// Copyright 2015 PingCAP, Inc. // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. // You may obtain a copy of the License at // // http://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. // See the License for the specific language governing permissions and // limitations under the License. // Copyright 2013 The ql Authors. All rights reserved. // Use of this source code is governed by a BSD-style // license that can be found in the LICENSES/QL-LICENSE file. package session import ( "bytes" "context" "crypto/tls" "encoding/hex" "encoding/json" stderrs "errors" "flag" "fmt" "math" "math/rand" "runtime/pprof" "runtime/trace" "strconv" "strings" "sync" "sync/atomic" "time" "github.com/ngaut/pools" "github.com/opentracing/opentracing-go" "github.com/pingcap/errors" "github.com/pingcap/failpoint" "github.com/pingcap/kvproto/pkg/kvrpcpb" "github.com/pingcap/tidb/bindinfo" "github.com/pingcap/tidb/config" "github.com/pingcap/tidb/ddl" "github.com/pingcap/tidb/ddl/placement" "github.com/pingcap/tidb/domain" "github.com/pingcap/tidb/domain/infosync" "github.com/pingcap/tidb/errno" "github.com/pingcap/tidb/executor" "github.com/pingcap/tidb/expression" "github.com/pingcap/tidb/extension" "github.com/pingcap/tidb/extension/extensionimpl" "github.com/pingcap/tidb/infoschema" "github.com/pingcap/tidb/kv" "github.com/pingcap/tidb/meta" "github.com/pingcap/tidb/metrics" "github.com/pingcap/tidb/owner" "github.com/pingcap/tidb/parser" "github.com/pingcap/tidb/parser/ast" "github.com/pingcap/tidb/parser/auth" "github.com/pingcap/tidb/parser/charset" "github.com/pingcap/tidb/parser/model" "github.com/pingcap/tidb/parser/mysql" "github.com/pingcap/tidb/parser/terror" "github.com/pingcap/tidb/planner" plannercore "github.com/pingcap/tidb/planner/core" "github.com/pingcap/tidb/plugin" "github.com/pingcap/tidb/privilege" "github.com/pingcap/tidb/privilege/privileges" "github.com/pingcap/tidb/session/txninfo" "github.com/pingcap/tidb/sessionctx" "github.com/pingcap/tidb/sessionctx/binloginfo" "github.com/pingcap/tidb/sessionctx/sessionstates" "github.com/pingcap/tidb/sessionctx/stmtctx" "github.com/pingcap/tidb/sessionctx/variable" "github.com/pingcap/tidb/sessiontxn" "github.com/pingcap/tidb/statistics" "github.com/pingcap/tidb/statistics/handle" storeerr "github.com/pingcap/tidb/store/driver/error" "github.com/pingcap/tidb/store/driver/txn" "github.com/pingcap/tidb/store/helper" "github.com/pingcap/tidb/table" "github.com/pingcap/tidb/table/temptable" "github.com/pingcap/tidb/tablecodec" "github.com/pingcap/tidb/telemetry" "github.com/pingcap/tidb/ttl/ttlworker" "github.com/pingcap/tidb/util" "github.com/pingcap/tidb/util/chunk" "github.com/pingcap/tidb/util/collate" "github.com/pingcap/tidb/util/dbterror" "github.com/pingcap/tidb/util/execdetails" "github.com/pingcap/tidb/util/kvcache" "github.com/pingcap/tidb/util/logutil" "github.com/pingcap/tidb/util/logutil/consistency" "github.com/pingcap/tidb/util/memory" "github.com/pingcap/tidb/util/sem" "github.com/pingcap/tidb/util/sli" "github.com/pingcap/tidb/util/sqlexec" "github.com/pingcap/tidb/util/syncutil" "github.com/pingcap/tidb/util/tableutil" "github.com/pingcap/tidb/util/timeutil" "github.com/pingcap/tidb/util/topsql" topsqlstate "github.com/pingcap/tidb/util/topsql/state" "github.com/pingcap/tidb/util/topsql/stmtstats" "github.com/pingcap/tipb/go-binlog" tikverr "github.com/tikv/client-go/v2/error" tikvstore "github.com/tikv/client-go/v2/kv" "github.com/tikv/client-go/v2/oracle" tikvutil "github.com/tikv/client-go/v2/util" "go.uber.org/zap" ) var ( statementPerTransactionPessimisticOK = metrics.StatementPerTransaction.WithLabelValues(metrics.LblPessimistic, metrics.LblOK) statementPerTransactionPessimisticError = metrics.StatementPerTransaction.WithLabelValues(metrics.LblPessimistic, metrics.LblError) statementPerTransactionOptimisticOK = metrics.StatementPerTransaction.WithLabelValues(metrics.LblOptimistic, metrics.LblOK) statementPerTransactionOptimisticError = metrics.StatementPerTransaction.WithLabelValues(metrics.LblOptimistic, metrics.LblError) transactionDurationPessimisticCommit = metrics.TransactionDuration.WithLabelValues(metrics.LblPessimistic, metrics.LblCommit) transactionDurationPessimisticAbort = metrics.TransactionDuration.WithLabelValues(metrics.LblPessimistic, metrics.LblAbort) transactionDurationOptimisticCommit = metrics.TransactionDuration.WithLabelValues(metrics.LblOptimistic, metrics.LblCommit) transactionDurationOptimisticAbort = metrics.TransactionDuration.WithLabelValues(metrics.LblOptimistic, metrics.LblAbort) sessionExecuteCompileDurationInternal = metrics.SessionExecuteCompileDuration.WithLabelValues(metrics.LblInternal) sessionExecuteCompileDurationGeneral = metrics.SessionExecuteCompileDuration.WithLabelValues(metrics.LblGeneral) sessionExecuteParseDurationInternal = metrics.SessionExecuteParseDuration.WithLabelValues(metrics.LblInternal) sessionExecuteParseDurationGeneral = metrics.SessionExecuteParseDuration.WithLabelValues(metrics.LblGeneral) telemetryCTEUsageRecurCTE = metrics.TelemetrySQLCTECnt.WithLabelValues("recurCTE") telemetryCTEUsageNonRecurCTE = metrics.TelemetrySQLCTECnt.WithLabelValues("nonRecurCTE") telemetryCTEUsageNotCTE = metrics.TelemetrySQLCTECnt.WithLabelValues("notCTE") telemetryMultiSchemaChangeUsage = metrics.TelemetryMultiSchemaChangeCnt telemetryFlashbackClusterUsage = metrics.TelemetryFlashbackClusterCnt telemetryTablePartitionUsage = metrics.TelemetryTablePartitionCnt telemetryTablePartitionListUsage = metrics.TelemetryTablePartitionListCnt telemetryTablePartitionRangeUsage = metrics.TelemetryTablePartitionRangeCnt telemetryTablePartitionHashUsage = metrics.TelemetryTablePartitionHashCnt telemetryTablePartitionRangeColumnsUsage = metrics.TelemetryTablePartitionRangeColumnsCnt telemetryTablePartitionRangeColumnsGt1Usage = metrics.TelemetryTablePartitionRangeColumnsGt1Cnt telemetryTablePartitionRangeColumnsGt2Usage = metrics.TelemetryTablePartitionRangeColumnsGt2Cnt telemetryTablePartitionRangeColumnsGt3Usage = metrics.TelemetryTablePartitionRangeColumnsGt3Cnt telemetryTablePartitionListColumnsUsage = metrics.TelemetryTablePartitionListColumnsCnt telemetryTablePartitionMaxPartitionsUsage = metrics.TelemetryTablePartitionMaxPartitionsCnt telemetryTablePartitionCreateIntervalUsage = metrics.TelemetryTablePartitionCreateIntervalPartitionsCnt telemetryTablePartitionAddIntervalUsage = metrics.TelemetryTablePartitionAddIntervalPartitionsCnt telemetryTablePartitionDropIntervalUsage = metrics.TelemetryTablePartitionDropIntervalPartitionsCnt telemetryExchangePartitionUsage = metrics.TelemetryExchangePartitionCnt telemetryTableCompactPartitionUsage = metrics.TelemetryCompactPartitionCnt telemetryLockUserUsage = metrics.TelemetryAccountLockCnt.WithLabelValues("lockUser") telemetryUnlockUserUsage = metrics.TelemetryAccountLockCnt.WithLabelValues("unlockUser") telemetryCreateOrAlterUserUsage = metrics.TelemetryAccountLockCnt.WithLabelValues("createOrAlterUser") telemetryIndexMerge = metrics.TelemetryIndexMergeUsage ) // Session context, it is consistent with the lifecycle of a client connection. type Session interface { sessionctx.Context Status() uint16 // Flag of current status, such as autocommit. LastInsertID() uint64 // LastInsertID is the last inserted auto_increment ID. LastMessage() string // LastMessage is the info message that may be generated by last command AffectedRows() uint64 // Affected rows by latest executed stmt. // Execute is deprecated, and only used by plugins. Use ExecuteStmt() instead. Execute(context.Context, string) ([]sqlexec.RecordSet, error) // Execute a sql statement. // ExecuteStmt executes a parsed statement. ExecuteStmt(context.Context, ast.StmtNode) (sqlexec.RecordSet, error) // Parse is deprecated, use ParseWithParams() instead. Parse(ctx context.Context, sql string) ([]ast.StmtNode, error) // ExecuteInternal is a helper around ParseWithParams() and ExecuteStmt(). It is not allowed to execute multiple statements. ExecuteInternal(context.Context, string, ...interface{}) (sqlexec.RecordSet, error) String() string // String is used to debug. CommitTxn(context.Context) error RollbackTxn(context.Context) // PrepareStmt executes prepare statement in binary protocol. PrepareStmt(sql string) (stmtID uint32, paramCount int, fields []*ast.ResultField, err error) // ExecutePreparedStmt executes a prepared statement. // Deprecated: please use ExecuteStmt, this function is left for testing only. // TODO: remove ExecutePreparedStmt. ExecutePreparedStmt(ctx context.Context, stmtID uint32, param []expression.Expression) (sqlexec.RecordSet, error) DropPreparedStmt(stmtID uint32) error // SetSessionStatesHandler sets SessionStatesHandler for type stateType. SetSessionStatesHandler(stateType sessionstates.SessionStateType, handler sessionctx.SessionStatesHandler) SetClientCapability(uint32) // Set client capability flags. SetConnectionID(uint64) SetCommandValue(byte) SetProcessInfo(string, time.Time, byte, uint64) SetTLSState(*tls.ConnectionState) SetCollation(coID int) error SetSessionManager(util.SessionManager) Close() Auth(user *auth.UserIdentity, auth, salt []byte) error AuthWithoutVerification(user *auth.UserIdentity) bool AuthPluginForUser(user *auth.UserIdentity) (string, error) MatchIdentity(username, remoteHost string) (*auth.UserIdentity, error) // Return the information of the txn current running TxnInfo() *txninfo.TxnInfo // PrepareTxnCtx is exported for test. PrepareTxnCtx(context.Context) error // FieldList returns fields list of a table. FieldList(tableName string) (fields []*ast.ResultField, err error) SetPort(port string) // set cur session operations allowed when tikv disk full happens. SetDiskFullOpt(level kvrpcpb.DiskFullOpt) GetDiskFullOpt() kvrpcpb.DiskFullOpt ClearDiskFullOpt() // SetExtensions sets the `*extension.SessionExtensions` object SetExtensions(extensions *extension.SessionExtensions) } var _ Session = (*session)(nil) type stmtRecord struct { st sqlexec.Statement stmtCtx *stmtctx.StatementContext } // StmtHistory holds all histories of statements in a txn. type StmtHistory struct { history []*stmtRecord } // Add appends a stmt to history list. func (h *StmtHistory) Add(st sqlexec.Statement, stmtCtx *stmtctx.StatementContext) { s := &stmtRecord{ st: st, stmtCtx: stmtCtx, } h.history = append(h.history, s) } // Count returns the count of the history. func (h *StmtHistory) Count() int { return len(h.history) } type session struct { // processInfo is used by ShowProcess(), and should be modified atomically. processInfo atomic.Value txn LazyTxn mu struct { sync.RWMutex values map[fmt.Stringer]interface{} } currentCtx context.Context // only use for runtime.trace, Please NEVER use it. currentPlan plannercore.Plan store kv.Storage preparedPlanCache sessionctx.PlanCache nonPreparedPlanCache sessionctx.PlanCache sessionVars *variable.SessionVars sessionManager util.SessionManager statsCollector *handle.SessionStatsCollector // ddlOwnerManager is used in `select tidb_is_ddl_owner()` statement; ddlOwnerManager owner.Manager // lockedTables use to record the table locks hold by the session. lockedTables map[int64]model.TableLockTpInfo // client shared coprocessor client per session client kv.Client mppClient kv.MPPClient // indexUsageCollector collects index usage information. idxUsageCollector *handle.SessionIndexUsageCollector functionUsageMu struct { syncutil.RWMutex builtinFunctionUsage telemetry.BuiltinFunctionsUsage } // allowed when tikv disk full happened. diskFullOpt kvrpcpb.DiskFullOpt // StmtStats is used to count various indicators of each SQL in this session // at each point in time. These data will be periodically taken away by the // background goroutine. The background goroutine will continue to aggregate // all the local data in each session, and finally report them to the remote // regularly. stmtStats *stmtstats.StatementStats // Used to encode and decode each type of session states. sessionStatesHandlers map[sessionstates.SessionStateType]sessionctx.SessionStatesHandler // Contains a list of sessions used to collect advisory locks. advisoryLocks map[string]*advisoryLock extensions *extension.SessionExtensions sandBoxMode bool } var parserPool = &sync.Pool{New: func() interface{} { return parser.New() }} // AddTableLock adds table lock to the session lock map. func (s *session) AddTableLock(locks []model.TableLockTpInfo) { for _, l := range locks { // read only lock is session unrelated, skip it when adding lock to session. if l.Tp != model.TableLockReadOnly { s.lockedTables[l.TableID] = l } } } // ReleaseTableLocks releases table lock in the session lock map. func (s *session) ReleaseTableLocks(locks []model.TableLockTpInfo) { for _, l := range locks { delete(s.lockedTables, l.TableID) } } // ReleaseTableLockByTableIDs releases table lock in the session lock map by table ID. func (s *session) ReleaseTableLockByTableIDs(tableIDs []int64) { for _, tblID := range tableIDs { delete(s.lockedTables, tblID) } } // CheckTableLocked checks the table lock. func (s *session) CheckTableLocked(tblID int64) (bool, model.TableLockType) { lt, ok := s.lockedTables[tblID] if !ok { return false, model.TableLockNone } return true, lt.Tp } // GetAllTableLocks gets all table locks table id and db id hold by the session. func (s *session) GetAllTableLocks() []model.TableLockTpInfo { lockTpInfo := make([]model.TableLockTpInfo, 0, len(s.lockedTables)) for _, tl := range s.lockedTables { lockTpInfo = append(lockTpInfo, tl) } return lockTpInfo } // HasLockedTables uses to check whether this session locked any tables. // If so, the session can only visit the table which locked by self. func (s *session) HasLockedTables() bool { b := len(s.lockedTables) > 0 return b } // ReleaseAllTableLocks releases all table locks hold by the session. func (s *session) ReleaseAllTableLocks() { s.lockedTables = make(map[int64]model.TableLockTpInfo) } // IsDDLOwner checks whether this session is DDL owner. func (s *session) IsDDLOwner() bool { return s.ddlOwnerManager.IsOwner() } func (s *session) cleanRetryInfo() { if s.sessionVars.RetryInfo.Retrying { return } retryInfo := s.sessionVars.RetryInfo defer retryInfo.Clean() if len(retryInfo.DroppedPreparedStmtIDs) == 0 { return } planCacheEnabled := s.GetSessionVars().EnablePreparedPlanCache var cacheKey kvcache.Key var err error var preparedAst *ast.Prepared var stmtText, stmtDB string if planCacheEnabled { firstStmtID := retryInfo.DroppedPreparedStmtIDs[0] if preparedPointer, ok := s.sessionVars.PreparedStmts[firstStmtID]; ok { preparedObj, ok := preparedPointer.(*plannercore.PlanCacheStmt) if ok { preparedAst = preparedObj.PreparedAst stmtText, stmtDB = preparedObj.StmtText, preparedObj.StmtDB bindSQL, _ := plannercore.GetBindSQL4PlanCache(s, preparedObj) cacheKey, err = plannercore.NewPlanCacheKey(s.sessionVars, stmtText, stmtDB, preparedAst.SchemaVersion, 0, bindSQL) if err != nil { logutil.Logger(s.currentCtx).Warn("clean cached plan failed", zap.Error(err)) return } } } } for i, stmtID := range retryInfo.DroppedPreparedStmtIDs { if planCacheEnabled { if i > 0 && preparedAst != nil { plannercore.SetPstmtIDSchemaVersion(cacheKey, stmtText, preparedAst.SchemaVersion, s.sessionVars.IsolationReadEngines) } if !s.sessionVars.IgnorePreparedCacheCloseStmt { // keep the plan in cache s.GetPlanCache(false).Delete(cacheKey) } } s.sessionVars.RemovePreparedStmt(stmtID) } } func (s *session) Status() uint16 { return s.sessionVars.Status } func (s *session) LastInsertID() uint64 { if s.sessionVars.StmtCtx.LastInsertID > 0 { return s.sessionVars.StmtCtx.LastInsertID } return s.sessionVars.StmtCtx.InsertID } func (s *session) LastMessage() string { return s.sessionVars.StmtCtx.GetMessage() } func (s *session) AffectedRows() uint64 { return s.sessionVars.StmtCtx.AffectedRows() } func (s *session) SetClientCapability(capability uint32) { s.sessionVars.ClientCapability = capability } func (s *session) SetConnectionID(connectionID uint64) { s.sessionVars.ConnectionID = connectionID } func (s *session) SetTLSState(tlsState *tls.ConnectionState) { // If user is not connected via TLS, then tlsState == nil. if tlsState != nil { s.sessionVars.TLSConnectionState = tlsState } } func (s *session) SetCommandValue(command byte) { atomic.StoreUint32(&s.sessionVars.CommandValue, uint32(command)) } func (s *session) SetCollation(coID int) error { cs, co, err := charset.GetCharsetInfoByID(coID) if err != nil { return err } // If new collations are enabled, switch to the default // collation if this one is not supported. co = collate.SubstituteMissingCollationToDefault(co) for _, v := range variable.SetNamesVariables { terror.Log(s.sessionVars.SetSystemVarWithoutValidation(v, cs)) } return s.sessionVars.SetSystemVarWithoutValidation(variable.CollationConnection, co) } func (s *session) GetPlanCache(isNonPrepared bool) sessionctx.PlanCache { if isNonPrepared { // use the non-prepared plan cache if !s.GetSessionVars().EnableNonPreparedPlanCache { return nil } if s.nonPreparedPlanCache == nil { // lazy construction s.nonPreparedPlanCache = plannercore.NewLRUPlanCache(uint(s.GetSessionVars().NonPreparedPlanCacheSize), variable.PreparedPlanCacheMemoryGuardRatio.Load(), plannercore.PreparedPlanCacheMaxMemory.Load(), s) } return s.nonPreparedPlanCache } // use the prepared plan cache if !s.GetSessionVars().EnablePreparedPlanCache { return nil } if s.preparedPlanCache == nil { // lazy construction s.preparedPlanCache = plannercore.NewLRUPlanCache(uint(s.GetSessionVars().PreparedPlanCacheSize), variable.PreparedPlanCacheMemoryGuardRatio.Load(), plannercore.PreparedPlanCacheMaxMemory.Load(), s) } return s.preparedPlanCache } func (s *session) SetSessionManager(sm util.SessionManager) { s.sessionManager = sm } func (s *session) GetSessionManager() util.SessionManager { return s.sessionManager } func (s *session) StoreQueryFeedback(feedback interface{}) { if variable.FeedbackProbability.Load() <= 0 { return } if fb, ok := feedback.(*statistics.QueryFeedback); !ok || fb == nil || !fb.Valid.Load() { return } if s.statsCollector != nil { do, err := GetDomain(s.store) if err != nil { logutil.BgLogger().Debug("domain not found", zap.Error(err)) metrics.StoreQueryFeedbackCounter.WithLabelValues(metrics.LblError).Inc() return } err = s.statsCollector.StoreQueryFeedback(feedback, do.StatsHandle(), s.GetSessionVars().GetEnablePseudoForOutdatedStats()) if err != nil { logutil.BgLogger().Debug("store query feedback", zap.Error(err)) metrics.StoreQueryFeedbackCounter.WithLabelValues(metrics.LblError).Inc() return } metrics.StoreQueryFeedbackCounter.WithLabelValues(metrics.LblOK).Inc() } } func (s *session) UpdateColStatsUsage(predicateColumns []model.TableItemID) { if s.statsCollector == nil { return } t := time.Now() colMap := make(map[model.TableItemID]time.Time, len(predicateColumns)) for _, col := range predicateColumns { if col.IsIndex { continue } colMap[col] = t } s.statsCollector.UpdateColStatsUsage(colMap) } // StoreIndexUsage stores index usage information in idxUsageCollector. func (s *session) StoreIndexUsage(tblID int64, idxID int64, rowsSelected int64) { if s.idxUsageCollector == nil { return } s.idxUsageCollector.Update(tblID, idxID, &handle.IndexUsageInformation{QueryCount: 1, RowsSelected: rowsSelected}) } // FieldList returns fields list of a table. func (s *session) FieldList(tableName string) ([]*ast.ResultField, error) { is := s.GetInfoSchema().(infoschema.InfoSchema) dbName := model.NewCIStr(s.GetSessionVars().CurrentDB) tName := model.NewCIStr(tableName) pm := privilege.GetPrivilegeManager(s) if pm != nil && s.sessionVars.User != nil { if !pm.RequestVerification(s.sessionVars.ActiveRoles, dbName.O, tName.O, "", mysql.AllPrivMask) { user := s.sessionVars.User u := user.Username h := user.Hostname if len(user.AuthUsername) > 0 && len(user.AuthHostname) > 0 { u = user.AuthUsername h = user.AuthHostname } return nil, plannercore.ErrTableaccessDenied.GenWithStackByArgs("SELECT", u, h, tableName) } } table, err := is.TableByName(dbName, tName) if err != nil { return nil, err } cols := table.Cols() fields := make([]*ast.ResultField, 0, len(cols)) for _, col := range table.Cols() { rf := &ast.ResultField{ ColumnAsName: col.Name, TableAsName: tName, DBName: dbName, Table: table.Meta(), Column: col.ColumnInfo, } fields = append(fields, rf) } return fields, nil } // TxnInfo returns a pointer to a *copy* of the internal TxnInfo, thus is *read only* func (s *session) TxnInfo() *txninfo.TxnInfo { s.txn.mu.RLock() // Copy on read to get a snapshot, this API shouldn't be frequently called. txnInfo := s.txn.mu.TxnInfo s.txn.mu.RUnlock() if txnInfo.StartTS == 0 { return nil } processInfo := s.ShowProcess() txnInfo.ConnectionID = processInfo.ID txnInfo.Username = processInfo.User txnInfo.CurrentDB = processInfo.DB txnInfo.RelatedTableIDs = make(map[int64]struct{}) s.GetSessionVars().GetRelatedTableForMDL().Range(func(key, value interface{}) bool { txnInfo.RelatedTableIDs[key.(int64)] = struct{}{} return true }) return &txnInfo } func (s *session) doCommit(ctx context.Context) error { if !s.txn.Valid() { return nil } // to avoid session set overlap the txn set. if s.GetDiskFullOpt() != kvrpcpb.DiskFullOpt_NotAllowedOnFull { s.txn.SetDiskFullOpt(s.GetDiskFullOpt()) } defer func() { s.txn.changeToInvalid() s.sessionVars.SetInTxn(false) s.ClearDiskFullOpt() }() // check if the transaction is read-only if s.txn.IsReadOnly() { return nil } // check if the cluster is read-only if !s.sessionVars.InRestrictedSQL && variable.RestrictedReadOnly.Load() || variable.VarTiDBSuperReadOnly.Load() { // It is not internal SQL, and the cluster has one of RestrictedReadOnly or SuperReadOnly // We need to privilege check again: a privilege check occurred during planning, but we need // to prevent the case that a long running auto-commit statement is now trying to commit. pm := privilege.GetPrivilegeManager(s) roles := s.sessionVars.ActiveRoles if pm != nil && !pm.HasExplicitlyGrantedDynamicPrivilege(roles, "RESTRICTED_REPLICA_WRITER_ADMIN", false) { s.RollbackTxn(ctx) return plannercore.ErrSQLInReadOnlyMode } } err := s.checkPlacementPolicyBeforeCommit() if err != nil { return err } // mockCommitError and mockGetTSErrorInRetry use to test PR #8743. failpoint.Inject("mockCommitError", func(val failpoint.Value) { if val.(bool) { if _, err := failpoint.Eval("tikvclient/mockCommitErrorOpt"); err == nil { failpoint.Return(kv.ErrTxnRetryable) } } }) if s.sessionVars.BinlogClient != nil { prewriteValue := binloginfo.GetPrewriteValue(s, false) if prewriteValue != nil { prewriteData, err := prewriteValue.Marshal() if err != nil { return errors.Trace(err) } info := &binloginfo.BinlogInfo{ Data: &binlog.Binlog{ Tp: binlog.BinlogType_Prewrite, PrewriteValue: prewriteData, }, Client: s.sessionVars.BinlogClient, } s.txn.SetOption(kv.BinlogInfo, info) } } sessVars := s.GetSessionVars() // Get the related table or partition IDs. relatedPhysicalTables := sessVars.TxnCtx.TableDeltaMap // Get accessed temporary tables in the transaction. temporaryTables := sessVars.TxnCtx.TemporaryTables physicalTableIDs := make([]int64, 0, len(relatedPhysicalTables)) for id := range relatedPhysicalTables { // Schema change on global temporary tables doesn't affect transactions. if _, ok := temporaryTables[id]; ok { continue } physicalTableIDs = append(physicalTableIDs, id) } needCheckSchema := true // Set this option for 2 phase commit to validate schema lease. if s.GetSessionVars().TxnCtx != nil { needCheckSchema = !s.GetSessionVars().TxnCtx.EnableMDL } s.txn.SetOption(kv.SchemaChecker, domain.NewSchemaChecker(domain.GetDomain(s), s.GetInfoSchema().SchemaMetaVersion(), physicalTableIDs, needCheckSchema)) s.txn.SetOption(kv.InfoSchema, s.sessionVars.TxnCtx.InfoSchema) s.txn.SetOption(kv.CommitHook, func(info string, _ error) { s.sessionVars.LastTxnInfo = info }) s.txn.SetOption(kv.EnableAsyncCommit, sessVars.EnableAsyncCommit) s.txn.SetOption(kv.Enable1PC, sessVars.Enable1PC) s.txn.SetOption(kv.ResourceGroupTagger, sessVars.StmtCtx.GetResourceGroupTagger()) s.txn.SetOption(kv.ResourceGroupName, sessVars.ResourceGroupName) if sessVars.StmtCtx.KvExecCounter != nil { // Bind an interceptor for client-go to count the number of SQL executions of each TiKV. s.txn.SetOption(kv.RPCInterceptor, sessVars.StmtCtx.KvExecCounter.RPCInterceptor()) } // priority of the sysvar is lower than `start transaction with causal consistency only` if val := s.txn.GetOption(kv.GuaranteeLinearizability); val == nil || val.(bool) { // We needn't ask the TiKV client to guarantee linearizability for auto-commit transactions // because the property is naturally holds: // We guarantee the commitTS of any transaction must not exceed the next timestamp from the TSO. // An auto-commit transaction fetches its startTS from the TSO so its commitTS > its startTS > the commitTS // of any previously committed transactions. s.txn.SetOption(kv.GuaranteeLinearizability, sessVars.TxnCtx.IsExplicit && sessVars.GuaranteeLinearizability) } if tables := sessVars.TxnCtx.TemporaryTables; len(tables) > 0 { s.txn.SetOption(kv.KVFilter, temporaryTableKVFilter(tables)) } s.txn.SetOption(kv.TxnSource, sessVars.CDCWriteSource) if tables := sessVars.TxnCtx.CachedTables; len(tables) > 0 { c := cachedTableRenewLease{tables: tables} now := time.Now() err := c.start(ctx) defer c.stop(ctx) sessVars.StmtCtx.WaitLockLeaseTime += time.Since(now) if err != nil { return errors.Trace(err) } s.txn.SetOption(kv.CommitTSUpperBoundCheck, c.commitTSCheck) } err = s.commitTxnWithTemporaryData(tikvutil.SetSessionID(ctx, sessVars.ConnectionID), &s.txn) if err != nil { err = s.handleAssertionFailure(ctx, err) } return err } type cachedTableRenewLease struct { tables map[int64]interface{} lease []uint64 // Lease for each visited cached tables. exit chan struct{} } func (c *cachedTableRenewLease) start(ctx context.Context) error { c.exit = make(chan struct{}) c.lease = make([]uint64, len(c.tables)) wg := make(chan error, len(c.tables)) ith := 0 for _, raw := range c.tables { tbl := raw.(table.CachedTable) go tbl.WriteLockAndKeepAlive(ctx, c.exit, &c.lease[ith], wg) ith++ } // Wait for all LockForWrite() return, this function can return. var err error for ; ith > 0; ith-- { tmp := <-wg if tmp != nil { err = tmp } } return err } func (c *cachedTableRenewLease) stop(ctx context.Context) { close(c.exit) } func (c *cachedTableRenewLease) commitTSCheck(commitTS uint64) bool { for i := 0; i < len(c.lease); i++ { lease := atomic.LoadUint64(&c.lease[i]) if commitTS >= lease { // Txn fails to commit because the write lease is expired. return false } } return true } // handleAssertionFailure extracts the possible underlying assertionFailed error, // gets the corresponding MVCC history and logs it. // If it's not an assertion failure, returns the original error. func (s *session) handleAssertionFailure(ctx context.Context, err error) error { var assertionFailure *tikverr.ErrAssertionFailed if !stderrs.As(err, &assertionFailure) { return err } key := assertionFailure.Key newErr := kv.ErrAssertionFailed.GenWithStackByArgs( hex.EncodeToString(key), assertionFailure.Assertion.String(), assertionFailure.StartTs, assertionFailure.ExistingStartTs, assertionFailure.ExistingCommitTs, ) if s.GetSessionVars().EnableRedactLog { return newErr } var decodeFunc func(kv.Key, *kvrpcpb.MvccGetByKeyResponse, map[string]interface{}) // if it's a record key or an index key, decode it if infoSchema, ok := s.sessionVars.TxnCtx.InfoSchema.(infoschema.InfoSchema); ok && infoSchema != nil && (tablecodec.IsRecordKey(key) || tablecodec.IsIndexKey(key)) { tableID := tablecodec.DecodeTableID(key) if table, ok := infoSchema.TableByID(tableID); ok { if tablecodec.IsRecordKey(key) { decodeFunc = consistency.DecodeRowMvccData(table.Meta()) } else { tableInfo := table.Meta() _, indexID, _, e := tablecodec.DecodeIndexKey(key) if e != nil { logutil.Logger(ctx).Error("assertion failed but cannot decode index key", zap.Error(e)) return err } var indexInfo *model.IndexInfo for _, idx := range tableInfo.Indices { if idx.ID == indexID { indexInfo = idx break } } if indexInfo == nil { return err } decodeFunc = consistency.DecodeIndexMvccData(indexInfo) } } else { logutil.Logger(ctx).Warn("assertion failed but table not found in infoschema", zap.Int64("tableID", tableID)) } } if store, ok := s.store.(helper.Storage); ok { content := consistency.GetMvccByKey(store, key, decodeFunc) logutil.Logger(ctx).Error("assertion failed", zap.String("message", newErr.Error()), zap.String("mvcc history", content)) } return newErr } func (s *session) commitTxnWithTemporaryData(ctx context.Context, txn kv.Transaction) error { sessVars := s.sessionVars txnTempTables := sessVars.TxnCtx.TemporaryTables if len(txnTempTables) == 0 { failpoint.Inject("mockSleepBeforeTxnCommit", func(v failpoint.Value) { ms := v.(int) time.Sleep(time.Millisecond * time.Duration(ms)) }) return txn.Commit(ctx) } sessionData := sessVars.TemporaryTableData var ( stage kv.StagingHandle localTempTables *infoschema.SessionTables ) if sessVars.LocalTemporaryTables != nil { localTempTables = sessVars.LocalTemporaryTables.(*infoschema.SessionTables) } else { localTempTables = new(infoschema.SessionTables) } defer func() { // stage != kv.InvalidStagingHandle means error occurs, we need to cleanup sessionData if stage != kv.InvalidStagingHandle { sessionData.Cleanup(stage) } }() for tblID, tbl := range txnTempTables { if !tbl.GetModified() { continue } if tbl.GetMeta().TempTableType != model.TempTableLocal { continue } if _, ok := localTempTables.TableByID(tblID); !ok { continue } if stage == kv.InvalidStagingHandle { stage = sessionData.Staging() } tblPrefix := tablecodec.EncodeTablePrefix(tblID) endKey := tablecodec.EncodeTablePrefix(tblID + 1) txnMemBuffer := s.txn.GetMemBuffer() iter, err := txnMemBuffer.Iter(tblPrefix, endKey) if err != nil { return err } for iter.Valid() { key := iter.Key() if !bytes.HasPrefix(key, tblPrefix) { break } value := iter.Value() if len(value) == 0 { err = sessionData.DeleteTableKey(tblID, key) } else { err = sessionData.SetTableKey(tblID, key, iter.Value()) } if err != nil { return err } err = iter.Next() if err != nil { return err } } } err := txn.Commit(ctx) if err != nil { return err } if stage != kv.InvalidStagingHandle { sessionData.Release(stage) stage = kv.InvalidStagingHandle } return nil } type temporaryTableKVFilter map[int64]tableutil.TempTable func (m temporaryTableKVFilter) IsUnnecessaryKeyValue(key, value []byte, flags tikvstore.KeyFlags) (bool, error) { tid := tablecodec.DecodeTableID(key) if _, ok := m[tid]; ok { return true, nil } // This is the default filter for all tables. defaultFilter := txn.TiDBKVFilter{} return defaultFilter.IsUnnecessaryKeyValue(key, value, flags) } // errIsNoisy is used to filter DUPLCATE KEY errors. // These can observed by users in INFORMATION_SCHEMA.CLIENT_ERRORS_SUMMARY_GLOBAL instead. // // The rationale for filtering these errors is because they are "client generated errors". i.e. // of the errors defined in kv/error.go, these look to be clearly related to a client-inflicted issue, // and the server is only responsible for handling the error correctly. It does not need to log. func errIsNoisy(err error) bool { if kv.ErrKeyExists.Equal(err) { return true } if storeerr.ErrLockAcquireFailAndNoWaitSet.Equal(err) { return true } return false } func (s *session) doCommitWithRetry(ctx context.Context) error { defer func() { s.GetSessionVars().SetTxnIsolationLevelOneShotStateForNextTxn() s.txn.changeToInvalid() s.cleanRetryInfo() sessiontxn.GetTxnManager(s).OnTxnEnd() }() if !s.txn.Valid() { // If the transaction is invalid, maybe it has already been rolled back by the client. return nil } var err error txnSize := s.txn.Size() isPessimistic := s.txn.IsPessimistic() if span := opentracing.SpanFromContext(ctx); span != nil && span.Tracer() != nil { span1 := span.Tracer().StartSpan("session.doCommitWitRetry", opentracing.ChildOf(span.Context())) defer span1.Finish() ctx = opentracing.ContextWithSpan(ctx, span1) } err = s.doCommit(ctx) if err != nil { // polish the Write Conflict error message newErr := s.tryReplaceWriteConflictError(err) if newErr != nil { err = newErr } commitRetryLimit := s.sessionVars.RetryLimit if !s.sessionVars.TxnCtx.CouldRetry { commitRetryLimit = 0 } // Don't retry in BatchInsert mode. As a counter-example, insert into t1 select * from t2, // BatchInsert already commit the first batch 1000 rows, then it commit 1000-2000 and retry the statement, // Finally t1 will have more data than t2, with no errors return to user! if s.isTxnRetryableError(err) && !s.sessionVars.BatchInsert && commitRetryLimit > 0 && !isPessimistic { logutil.Logger(ctx).Warn("sql", zap.String("label", s.GetSQLLabel()), zap.Error(err), zap.String("txn", s.txn.GoString())) // Transactions will retry 2 ~ commitRetryLimit times. // We make larger transactions retry less times to prevent cluster resource outage. txnSizeRate := float64(txnSize) / float64(kv.TxnTotalSizeLimit) maxRetryCount := commitRetryLimit - int64(float64(commitRetryLimit-1)*txnSizeRate) err = s.retry(ctx, uint(maxRetryCount)) } else if !errIsNoisy(err) { logutil.Logger(ctx).Warn("can not retry txn", zap.String("label", s.GetSQLLabel()), zap.Error(err), zap.Bool("IsBatchInsert", s.sessionVars.BatchInsert), zap.Bool("IsPessimistic", isPessimistic), zap.Bool("InRestrictedSQL", s.sessionVars.InRestrictedSQL), zap.Int64("tidb_retry_limit", s.sessionVars.RetryLimit), zap.Bool("tidb_disable_txn_auto_retry", s.sessionVars.DisableTxnAutoRetry)) } } counter := s.sessionVars.TxnCtx.StatementCount duration := time.Since(s.GetSessionVars().TxnCtx.CreateTime).Seconds() s.recordOnTransactionExecution(err, counter, duration) if err != nil { if !errIsNoisy(err) { logutil.Logger(ctx).Warn("commit failed", zap.String("finished txn", s.txn.GoString()), zap.Error(err)) } return err } s.updateStatsDeltaToCollector() return nil } // adds more information about the table in the error message // precondition: oldErr is a 9007:WriteConflict Error func (s *session) tryReplaceWriteConflictError(oldErr error) (newErr error) { if !kv.ErrWriteConflict.Equal(oldErr) { return nil } if errors.RedactLogEnabled.Load() { return nil } originErr := errors.Cause(oldErr) inErr, _ := originErr.(*errors.Error) args := inErr.Args() is := sessiontxn.GetTxnManager(s).GetTxnInfoSchema() if is == nil { return nil } newKeyTableField, ok := addTableNameInTableIDField(args[3], is) if ok { args[3] = newKeyTableField } newPrimaryKeyTableField, ok := addTableNameInTableIDField(args[5], is) if ok { args[5] = newPrimaryKeyTableField } return kv.ErrWriteConflict.FastGenByArgs(args...) } // precondition: is != nil func addTableNameInTableIDField(tableIDField interface{}, is infoschema.InfoSchema) (enhancedMsg string, done bool) { keyTableID, ok := tableIDField.(string) if !ok { return "", false } stringsInTableIDField := strings.Split(keyTableID, "=") if len(stringsInTableIDField) == 0 { return "", false } tableIDStr := stringsInTableIDField[len(stringsInTableIDField)-1] tableID, err := strconv.ParseInt(tableIDStr, 10, 64) if err != nil { return "", false } var tableName string tbl, ok := is.TableByID(tableID) if !ok { tableName = "unknown" } else { dbInfo, ok := is.SchemaByTable(tbl.Meta()) if !ok { tableName = "unknown." + tbl.Meta().Name.String() } else { tableName = dbInfo.Name.String() + "." + tbl.Meta().Name.String() } } enhancedMsg = keyTableID + ", tableName=" + tableName return enhancedMsg, true } func (s *session) updateStatsDeltaToCollector() { mapper := s.GetSessionVars().TxnCtx.TableDeltaMap if s.statsCollector != nil && mapper != nil { for _, item := range mapper { if item.TableID > 0 { s.statsCollector.Update(item.TableID, item.Delta, item.Count, &item.ColSize) } } } } func (s *session) CommitTxn(ctx context.Context) error { if span := opentracing.SpanFromContext(ctx); span != nil && span.Tracer() != nil { span1 := span.Tracer().StartSpan("session.CommitTxn", opentracing.ChildOf(span.Context())) defer span1.Finish() ctx = opentracing.ContextWithSpan(ctx, span1) } var commitDetail *tikvutil.CommitDetails ctx = context.WithValue(ctx, tikvutil.CommitDetailCtxKey, &commitDetail) err := s.doCommitWithRetry(ctx) if commitDetail != nil { s.sessionVars.StmtCtx.MergeExecDetails(nil, commitDetail) } failpoint.Inject("keepHistory", func(val failpoint.Value) { if val.(bool) { failpoint.Return(err) } }) s.sessionVars.TxnCtx.Cleanup() s.sessionVars.CleanupTxnReadTSIfUsed() return err } func (s *session) RollbackTxn(ctx context.Context) { if span := opentracing.SpanFromContext(ctx); span != nil && span.Tracer() != nil { span1 := span.Tracer().StartSpan("session.RollbackTxn", opentracing.ChildOf(span.Context())) defer span1.Finish() } if s.txn.Valid() { terror.Log(s.txn.Rollback()) } if ctx.Value(inCloseSession{}) == nil { s.cleanRetryInfo() } s.txn.changeToInvalid() s.sessionVars.TxnCtx.Cleanup() s.sessionVars.CleanupTxnReadTSIfUsed() s.sessionVars.SetInTxn(false) sessiontxn.GetTxnManager(s).OnTxnEnd() } func (s *session) GetClient() kv.Client { return s.client } func (s *session) GetMPPClient() kv.MPPClient { return s.mppClient } func (s *session) String() string { // TODO: how to print binded context in values appropriately? sessVars := s.sessionVars data := map[string]interface{}{ "id": sessVars.ConnectionID, "user": sessVars.User, "currDBName": sessVars.CurrentDB, "status": sessVars.Status, "strictMode": sessVars.StrictSQLMode, } if s.txn.Valid() { // if txn is committed or rolled back, txn is nil. data["txn"] = s.txn.String() } if sessVars.SnapshotTS != 0 { data["snapshotTS"] = sessVars.SnapshotTS } if sessVars.StmtCtx.LastInsertID > 0 { data["lastInsertID"] = sessVars.StmtCtx.LastInsertID } if len(sessVars.PreparedStmts) > 0 { data["preparedStmtCount"] = len(sessVars.PreparedStmts) } b, err := json.MarshalIndent(data, "", " ") terror.Log(errors.Trace(err)) return string(b) } const sqlLogMaxLen = 1024 // SchemaChangedWithoutRetry is used for testing. var SchemaChangedWithoutRetry uint32 func (s *session) GetSQLLabel() string { if s.sessionVars.InRestrictedSQL { return metrics.LblInternal } return metrics.LblGeneral } func (s *session) isInternal() bool { return s.sessionVars.InRestrictedSQL } func (s *session) isTxnRetryableError(err error) bool { if atomic.LoadUint32(&SchemaChangedWithoutRetry) == 1 { return kv.IsTxnRetryableError(err) } return kv.IsTxnRetryableError(err) || domain.ErrInfoSchemaChanged.Equal(err) } func (s *session) checkTxnAborted(stmt sqlexec.Statement) error { var err error if atomic.LoadUint32(&s.GetSessionVars().TxnCtx.LockExpire) > 0 { err = kv.ErrLockExpire } else { return nil } // If the transaction is aborted, the following statements do not need to execute, except `commit` and `rollback`, // because they are used to finish the aborted transaction. if _, ok := stmt.(*executor.ExecStmt).StmtNode.(*ast.CommitStmt); ok { return nil } if _, ok := stmt.(*executor.ExecStmt).StmtNode.(*ast.RollbackStmt); ok { return nil } return err } func (s *session) retry(ctx context.Context, maxCnt uint) (err error) { var retryCnt uint defer func() { s.sessionVars.RetryInfo.Retrying = false // retryCnt only increments on retryable error, so +1 here. metrics.SessionRetry.Observe(float64(retryCnt + 1)) s.sessionVars.SetInTxn(false) if err != nil { s.RollbackTxn(ctx) } s.txn.changeToInvalid() }() connID := s.sessionVars.ConnectionID s.sessionVars.RetryInfo.Retrying = true if atomic.LoadUint32(&s.sessionVars.TxnCtx.ForUpdate) == 1 { err = ErrForUpdateCantRetry.GenWithStackByArgs(connID) return err } nh := GetHistory(s) var schemaVersion int64 sessVars := s.GetSessionVars() orgStartTS := sessVars.TxnCtx.StartTS label := s.GetSQLLabel() for { if err = s.PrepareTxnCtx(ctx); err != nil { return err } s.sessionVars.RetryInfo.ResetOffset() for i, sr := range nh.history { st := sr.st s.sessionVars.StmtCtx = sr.stmtCtx s.sessionVars.StmtCtx.ResetForRetry() s.sessionVars.PreparedParams = s.sessionVars.PreparedParams[:0] schemaVersion, err = st.RebuildPlan(ctx) if err != nil { return err } if retryCnt == 0 { // We do not have to log the query every time. // We print the queries at the first try only. sql := sqlForLog(st.GetTextToLog()) if !sessVars.EnableRedactLog { sql += sessVars.PreparedParams.String() } logutil.Logger(ctx).Warn("retrying", zap.Int64("schemaVersion", schemaVersion), zap.Uint("retryCnt", retryCnt), zap.Int("queryNum", i), zap.String("sql", sql)) } else { logutil.Logger(ctx).Warn("retrying", zap.Int64("schemaVersion", schemaVersion), zap.Uint("retryCnt", retryCnt), zap.Int("queryNum", i)) } _, digest := s.sessionVars.StmtCtx.SQLDigest() s.txn.onStmtStart(digest.String()) if err = sessiontxn.GetTxnManager(s).OnStmtStart(ctx, st.GetStmtNode()); err == nil { _, err = st.Exec(ctx) } s.txn.onStmtEnd() if err != nil { s.StmtRollback(ctx, false) break } s.StmtCommit(ctx) } logutil.Logger(ctx).Warn("transaction association", zap.Uint64("retrying txnStartTS", s.GetSessionVars().TxnCtx.StartTS), zap.Uint64("original txnStartTS", orgStartTS)) failpoint.Inject("preCommitHook", func() { hook, ok := ctx.Value("__preCommitHook").(func()) if ok { hook() } }) if err == nil { err = s.doCommit(ctx) if err == nil { break } } if !s.isTxnRetryableError(err) { logutil.Logger(ctx).Warn("sql", zap.String("label", label), zap.Stringer("session", s), zap.Error(err)) metrics.SessionRetryErrorCounter.WithLabelValues(label, metrics.LblUnretryable).Inc() return err } retryCnt++ if retryCnt >= maxCnt { logutil.Logger(ctx).Warn("sql", zap.String("label", label), zap.Uint("retry reached max count", retryCnt)) metrics.SessionRetryErrorCounter.WithLabelValues(label, metrics.LblReachMax).Inc() return err } logutil.Logger(ctx).Warn("sql", zap.String("label", label), zap.Error(err), zap.String("txn", s.txn.GoString())) kv.BackOff(retryCnt) s.txn.changeToInvalid() s.sessionVars.SetInTxn(false) } return err } func sqlForLog(sql string) string { if len(sql) > sqlLogMaxLen { sql = sql[:sqlLogMaxLen] + fmt.Sprintf("(len:%d)", len(sql)) } return executor.QueryReplacer.Replace(sql) } type sessionPool interface { Get() (pools.Resource, error) Put(pools.Resource) } func (s *session) sysSessionPool() sessionPool { return domain.GetDomain(s).SysSessionPool() } func createSessionFunc(store kv.Storage) pools.Factory { return func() (pools.Resource, error) { se, err := createSession(store) if err != nil { return nil, err } err = se.sessionVars.SetSystemVar(variable.AutoCommit, "1") if err != nil { return nil, err } err = se.sessionVars.SetSystemVar(variable.MaxExecutionTime, "0") if err != nil { return nil, errors.Trace(err) } err = se.sessionVars.SetSystemVar(variable.MaxAllowedPacket, strconv.FormatUint(variable.DefMaxAllowedPacket, 10)) if err != nil { return nil, errors.Trace(err) } err = se.sessionVars.SetSystemVar(variable.TiDBEnableWindowFunction, variable.BoolToOnOff(variable.DefEnableWindowFunction)) if err != nil { return nil, errors.Trace(err) } err = se.sessionVars.SetSystemVar(variable.TiDBConstraintCheckInPlacePessimistic, variable.On) if err != nil { return nil, errors.Trace(err) } se.sessionVars.CommonGlobalLoaded = true se.sessionVars.InRestrictedSQL = true // Internal session uses default format to prevent memory leak problem. se.sessionVars.EnableChunkRPC = false return se, nil } } func createSessionWithDomainFunc(store kv.Storage) func(*domain.Domain) (pools.Resource, error) { return func(dom *domain.Domain) (pools.Resource, error) { se, err := CreateSessionWithDomain(store, dom) if err != nil { return nil, err } err = se.sessionVars.SetSystemVar(variable.AutoCommit, "1") if err != nil { return nil, err } err = se.sessionVars.SetSystemVar(variable.MaxExecutionTime, "0") if err != nil { return nil, errors.Trace(err) } err = se.sessionVars.SetSystemVar(variable.MaxAllowedPacket, strconv.FormatUint(variable.DefMaxAllowedPacket, 10)) if err != nil { return nil, errors.Trace(err) } err = se.sessionVars.SetSystemVar(variable.TiDBConstraintCheckInPlacePessimistic, variable.On) if err != nil { return nil, errors.Trace(err) } se.sessionVars.CommonGlobalLoaded = true se.sessionVars.InRestrictedSQL = true // Internal session uses default format to prevent memory leak problem. se.sessionVars.EnableChunkRPC = false return se, nil } } func drainRecordSet(ctx context.Context, se *session, rs sqlexec.RecordSet, alloc chunk.Allocator) ([]chunk.Row, error) { var rows []chunk.Row var req *chunk.Chunk req = rs.NewChunk(alloc) for { err := rs.Next(ctx, req) if err != nil || req.NumRows() == 0 { return rows, err } iter := chunk.NewIterator4Chunk(req) for r := iter.Begin(); r != iter.End(); r = iter.Next() { rows = append(rows, r) } req = chunk.Renew(req, se.sessionVars.MaxChunkSize) } } // getTableValue executes restricted sql and the result is one column. // It returns a string value. func (s *session) getTableValue(ctx context.Context, tblName string, varName string) (string, error) { if ctx.Value(kv.RequestSourceKey) == nil { ctx = kv.WithInternalSourceType(ctx, kv.InternalTxnSysVar) } rows, fields, err := s.ExecRestrictedSQL(ctx, nil, "SELECT VARIABLE_VALUE FROM %n.%n WHERE VARIABLE_NAME=%?", mysql.SystemDB, tblName, varName) if err != nil { return "", err } if len(rows) == 0 { return "", errResultIsEmpty } d := rows[0].GetDatum(0, &fields[0].Column.FieldType) value, err := d.ToString() if err != nil { return "", err } return value, nil } // replaceGlobalVariablesTableValue executes restricted sql updates the variable value // It will then notify the etcd channel that the value has changed. func (s *session) replaceGlobalVariablesTableValue(ctx context.Context, varName, val string, updateLocal bool) error { ctx = kv.WithInternalSourceType(ctx, kv.InternalTxnSysVar) _, _, err := s.ExecRestrictedSQL(ctx, nil, `REPLACE INTO %n.%n (variable_name, variable_value) VALUES (%?, %?)`, mysql.SystemDB, mysql.GlobalVariablesTable, varName, val) if err != nil { return err } domain.GetDomain(s).NotifyUpdateSysVarCache(updateLocal) return err } // GetGlobalSysVar implements GlobalVarAccessor.GetGlobalSysVar interface. func (s *session) GetGlobalSysVar(name string) (string, error) { if s.Value(sessionctx.Initing) != nil { // When running bootstrap or upgrade, we should not access global storage. return "", nil } sv := variable.GetSysVar(name) if sv == nil { // It might be a recently unregistered sysvar. We should return unknown // since GetSysVar is the canonical version, but we can update the cache // so the next request doesn't attempt to load this. logutil.BgLogger().Info("sysvar does not exist. sysvar cache may be stale", zap.String("name", name)) return "", variable.ErrUnknownSystemVar.GenWithStackByArgs(name) } sysVar, err := domain.GetDomain(s).GetGlobalVar(name) if err != nil { // The sysvar exists, but there is no cache entry yet. // This might be because the sysvar was only recently registered. // In which case it is safe to return the default, but we can also // update the cache for the future. logutil.BgLogger().Info("sysvar not in cache yet. sysvar cache may be stale", zap.String("name", name)) sysVar, err = s.getTableValue(context.TODO(), mysql.GlobalVariablesTable, name) if err != nil { return sv.Value, nil } } // It might have been written from an earlier TiDB version, so we should do type validation // See https://github.com/pingcap/tidb/issues/30255 for why we don't do full validation. // If validation fails, we should return the default value: // See: https://github.com/pingcap/tidb/pull/31566 sysVar, err = sv.ValidateFromType(s.GetSessionVars(), sysVar, variable.ScopeGlobal) if err != nil { return sv.Value, nil } return sysVar, nil } // SetGlobalSysVar implements GlobalVarAccessor.SetGlobalSysVar interface. // it is called (but skipped) when setting instance scope func (s *session) SetGlobalSysVar(ctx context.Context, name string, value string) (err error) { sv := variable.GetSysVar(name) if sv == nil { return variable.ErrUnknownSystemVar.GenWithStackByArgs(name) } if value, err = sv.Validate(s.sessionVars, value, variable.ScopeGlobal); err != nil { return err } if err = sv.SetGlobalFromHook(ctx, s.sessionVars, value, false); err != nil { return err } if sv.HasInstanceScope() { // skip for INSTANCE scope return nil } if sv.GlobalConfigName != "" { domain.GetDomain(s).NotifyGlobalConfigChange(sv.GlobalConfigName, variable.OnOffToTrueFalse(value)) } return s.replaceGlobalVariablesTableValue(context.TODO(), sv.Name, value, true) } // SetGlobalSysVarOnly updates the sysvar, but does not call the validation function or update aliases. // This is helpful to prevent duplicate warnings being appended from aliases, or recursion. // updateLocal indicates whether to rebuild the local SysVar Cache. This is helpful to prevent recursion. func (s *session) SetGlobalSysVarOnly(ctx context.Context, name string, value string, updateLocal bool) (err error) { sv := variable.GetSysVar(name) if sv == nil { return variable.ErrUnknownSystemVar.GenWithStackByArgs(name) } if err = sv.SetGlobalFromHook(ctx, s.sessionVars, value, true); err != nil { return err } if sv.HasInstanceScope() { // skip for INSTANCE scope return nil } return s.replaceGlobalVariablesTableValue(ctx, sv.Name, value, updateLocal) } // SetTiDBTableValue implements GlobalVarAccessor.SetTiDBTableValue interface. func (s *session) SetTiDBTableValue(name, value, comment string) error { ctx := kv.WithInternalSourceType(context.Background(), kv.InternalTxnSysVar) _, _, err := s.ExecRestrictedSQL(ctx, nil, `REPLACE INTO mysql.tidb (variable_name, variable_value, comment) VALUES (%?, %?, %?)`, name, value, comment) return err } // GetTiDBTableValue implements GlobalVarAccessor.GetTiDBTableValue interface. func (s *session) GetTiDBTableValue(name string) (string, error) { return s.getTableValue(context.TODO(), mysql.TiDBTable, name) } var _ sqlexec.SQLParser = &session{} func (s *session) ParseSQL(ctx context.Context, sql string, params ...parser.ParseParam) ([]ast.StmtNode, []error, error) { if span := opentracing.SpanFromContext(ctx); span != nil && span.Tracer() != nil { span1 := span.Tracer().StartSpan("session.ParseSQL", opentracing.ChildOf(span.Context())) defer span1.Finish() } defer trace.StartRegion(ctx, "ParseSQL").End() p := parserPool.Get().(*parser.Parser) defer parserPool.Put(p) p.SetSQLMode(s.sessionVars.SQLMode) p.SetParserConfig(s.sessionVars.BuildParserConfig()) tmp, warn, err := p.ParseSQL(sql, params...) // The []ast.StmtNode is referenced by the parser, to reuse the parser, make a copy of the result. res := make([]ast.StmtNode, len(tmp)) copy(res, tmp) return res, warn, err } func (s *session) SetProcessInfo(sql string, t time.Time, command byte, maxExecutionTime uint64) { // If command == mysql.ComSleep, it means the SQL execution is finished. The processinfo is reset to SLEEP. // If the SQL finished and the session is not in transaction, the current start timestamp need to reset to 0. // Otherwise, it should be set to the transaction start timestamp. // Why not reset the transaction start timestamp to 0 when transaction committed? // Because the select statement and other statements need this timestamp to read data, // after the transaction is committed. e.g. SHOW MASTER STATUS; var curTxnStartTS uint64 if command != mysql.ComSleep || s.GetSessionVars().InTxn() { curTxnStartTS = s.sessionVars.TxnCtx.StartTS } // Set curTxnStartTS to SnapshotTS directly when the session is trying to historic read. // It will avoid the session meet GC lifetime too short error. if s.GetSessionVars().SnapshotTS != 0 { curTxnStartTS = s.GetSessionVars().SnapshotTS } p := s.currentPlan if explain, ok := p.(*plannercore.Explain); ok && explain.Analyze && explain.TargetPlan != nil { p = explain.TargetPlan } pi := util.ProcessInfo{ ID: s.sessionVars.ConnectionID, Port: s.sessionVars.Port, DB: s.sessionVars.CurrentDB, Command: command, Plan: p, PlanExplainRows: plannercore.GetExplainRowsForPlan(p), RuntimeStatsColl: s.sessionVars.StmtCtx.RuntimeStatsColl, Time: t, State: s.Status(), Info: sql, CurTxnStartTS: curTxnStartTS, StmtCtx: s.sessionVars.StmtCtx, RefCountOfStmtCtx: &s.sessionVars.RefCountOfStmtCtx, MemTracker: s.sessionVars.MemTracker, DiskTracker: s.sessionVars.DiskTracker, StatsInfo: plannercore.GetStatsInfo, OOMAlarmVariablesInfo: s.getOomAlarmVariablesInfo(), MaxExecutionTime: maxExecutionTime, RedactSQL: s.sessionVars.EnableRedactLog, ProtectedTSList: &s.sessionVars.ProtectedTSList, } oldPi := s.ShowProcess() if p == nil { // Store the last valid plan when the current plan is nil. // This is for `explain for connection` statement has the ability to query the last valid plan. if oldPi != nil && oldPi.Plan != nil && len(oldPi.PlanExplainRows) > 0 { pi.Plan = oldPi.Plan pi.PlanExplainRows = oldPi.PlanExplainRows pi.RuntimeStatsColl = oldPi.RuntimeStatsColl } } // We set process info before building plan, so we extended execution time. if oldPi != nil && oldPi.Info == pi.Info { pi.Time = oldPi.Time } _, digest := s.sessionVars.StmtCtx.SQLDigest() pi.Digest = digest.String() // DO NOT reset the currentPlan to nil until this query finishes execution, otherwise reentrant calls // of SetProcessInfo would override Plan and PlanExplainRows to nil. if command == mysql.ComSleep { s.currentPlan = nil } if s.sessionVars.User != nil { pi.User = s.sessionVars.User.Username pi.Host = s.sessionVars.User.Hostname } s.processInfo.Store(&pi) } func (s *session) getOomAlarmVariablesInfo() util.OOMAlarmVariablesInfo { return util.OOMAlarmVariablesInfo{ SessionAnalyzeVersion: s.sessionVars.AnalyzeVersion, SessionEnabledRateLimitAction: s.sessionVars.EnabledRateLimitAction, SessionMemQuotaQuery: s.sessionVars.MemQuotaQuery, } } func (s *session) SetDiskFullOpt(level kvrpcpb.DiskFullOpt) { s.diskFullOpt = level } func (s *session) GetDiskFullOpt() kvrpcpb.DiskFullOpt { return s.diskFullOpt } func (s *session) ClearDiskFullOpt() { s.diskFullOpt = kvrpcpb.DiskFullOpt_NotAllowedOnFull } func (s *session) ExecuteInternal(ctx context.Context, sql string, args ...interface{}) (rs sqlexec.RecordSet, err error) { origin := s.sessionVars.InRestrictedSQL s.sessionVars.InRestrictedSQL = true defer func() { s.sessionVars.InRestrictedSQL = origin // Restore the goroutine label by using the original ctx after execution is finished. pprof.SetGoroutineLabels(ctx) }() if span := opentracing.SpanFromContext(ctx); span != nil && span.Tracer() != nil { span1 := span.Tracer().StartSpan("session.ExecuteInternal", opentracing.ChildOf(span.Context())) defer span1.Finish() ctx = opentracing.ContextWithSpan(ctx, span1) logutil.Eventf(ctx, "execute: %s", sql) } stmtNode, err := s.ParseWithParams(ctx, sql, args...) if err != nil { return nil, err } rs, err = s.ExecuteStmt(ctx, stmtNode) if err != nil { s.sessionVars.StmtCtx.AppendError(err) } if rs == nil { return nil, err } return rs, err } // Execute is deprecated, we can remove it as soon as plugins are migrated. func (s *session) Execute(ctx context.Context, sql string) (recordSets []sqlexec.RecordSet, err error) { if span := opentracing.SpanFromContext(ctx); span != nil && span.Tracer() != nil { span1 := span.Tracer().StartSpan("session.Execute", opentracing.ChildOf(span.Context())) defer span1.Finish() ctx = opentracing.ContextWithSpan(ctx, span1) logutil.Eventf(ctx, "execute: %s", sql) } stmtNodes, err := s.Parse(ctx, sql) if err != nil { return nil, err } if len(stmtNodes) != 1 { return nil, errors.New("Execute() API doesn't support multiple statements any more") } rs, err := s.ExecuteStmt(ctx, stmtNodes[0]) if err != nil { s.sessionVars.StmtCtx.AppendError(err) } if rs == nil { return nil, err } return []sqlexec.RecordSet{rs}, err } // Parse parses a query string to raw ast.StmtNode. func (s *session) Parse(ctx context.Context, sql string) ([]ast.StmtNode, error) { parseStartTime := time.Now() stmts, warns, err := s.ParseSQL(ctx, sql, s.sessionVars.GetParseParams()...) if err != nil { s.rollbackOnError(ctx) err = util.SyntaxError(err) // Only print log message when this SQL is from the user. // Mute the warning for internal SQLs. if !s.sessionVars.InRestrictedSQL { if s.sessionVars.EnableRedactLog { logutil.Logger(ctx).Debug("parse SQL failed", zap.Error(err), zap.String("SQL", sql)) } else { logutil.Logger(ctx).Warn("parse SQL failed", zap.Error(err), zap.String("SQL", sql)) } s.sessionVars.StmtCtx.AppendError(err) } return nil, err } durParse := time.Since(parseStartTime) s.GetSessionVars().DurationParse = durParse isInternal := s.isInternal() if isInternal { sessionExecuteParseDurationInternal.Observe(durParse.Seconds()) } else { sessionExecuteParseDurationGeneral.Observe(durParse.Seconds()) } for _, warn := range warns { s.sessionVars.StmtCtx.AppendWarning(util.SyntaxWarn(warn)) } return stmts, nil } // ParseWithParams parses a query string, with arguments, to raw ast.StmtNode. // Note that it will not do escaping if no variable arguments are passed. func (s *session) ParseWithParams(ctx context.Context, sql string, args ...interface{}) (ast.StmtNode, error) { var err error if len(args) > 0 { sql, err = sqlexec.EscapeSQL(sql, args...) if err != nil { return nil, err } } internal := s.isInternal() var stmts []ast.StmtNode var warns []error parseStartTime := time.Now() if internal { // Do no respect the settings from clients, if it is for internal usage. // Charsets from clients may give chance injections. // Refer to https://stackoverflow.com/questions/5741187/sql-injection-that-gets-around-mysql-real-escape-string/12118602. stmts, warns, err = s.ParseSQL(ctx, sql) } else { stmts, warns, err = s.ParseSQL(ctx, sql, s.sessionVars.GetParseParams()...) } if len(stmts) != 1 { err = errors.New("run multiple statements internally is not supported") } if err != nil { s.rollbackOnError(ctx) // Only print log message when this SQL is from the user. // Mute the warning for internal SQLs. if !s.sessionVars.InRestrictedSQL { if s.sessionVars.EnableRedactLog { logutil.Logger(ctx).Debug("parse SQL failed", zap.Error(err), zap.String("SQL", sql)) } else { logutil.Logger(ctx).Warn("parse SQL failed", zap.Error(err), zap.String("SQL", sql)) } } return nil, util.SyntaxError(err) } durParse := time.Since(parseStartTime) if internal { sessionExecuteParseDurationInternal.Observe(durParse.Seconds()) } else { sessionExecuteParseDurationGeneral.Observe(durParse.Seconds()) } for _, warn := range warns { s.sessionVars.StmtCtx.AppendWarning(util.SyntaxWarn(warn)) } if topsqlstate.TopSQLEnabled() { normalized, digest := parser.NormalizeDigest(sql) if digest != nil { // Reset the goroutine label when internal sql execute finish. // Specifically reset in ExecRestrictedStmt function. s.sessionVars.StmtCtx.IsSQLRegistered.Store(true) topsql.AttachAndRegisterSQLInfo(ctx, normalized, digest, s.sessionVars.InRestrictedSQL) } } return stmts[0], nil } // GetAdvisoryLock acquires an advisory lock of lockName. // Note that a lock can be acquired multiple times by the same session, // in which case we increment a reference count. // Each lock needs to be held in a unique session because // we need to be able to ROLLBACK in any arbitrary order // in order to release the locks. func (s *session) GetAdvisoryLock(lockName string, timeout int64) error { if lock, ok := s.advisoryLocks[lockName]; ok { lock.IncrReferences() return nil } sess, err := createSession(s.store) if err != nil { return err } infosync.StoreInternalSession(sess) lock := &advisoryLock{session: sess, ctx: context.TODO()} err = lock.GetLock(lockName, timeout) if err != nil { return err } s.advisoryLocks[lockName] = lock return nil } // ReleaseAdvisoryLock releases an advisory locks held by the session. // It returns FALSE if no lock by this name was held (by this session), // and TRUE if a lock was held and "released". // Note that the lock is not actually released if there are multiple // references to the same lockName by the session, instead the reference // count is decremented. func (s *session) ReleaseAdvisoryLock(lockName string) (released bool) { if lock, ok := s.advisoryLocks[lockName]; ok { lock.DecrReferences() if lock.ReferenceCount() <= 0 { lock.Close() delete(s.advisoryLocks, lockName) infosync.DeleteInternalSession(lock.session) } return true } return false } // ReleaseAllAdvisoryLocks releases all advisory locks held by the session // and returns a count of the locks that were released. // The count is based on unique locks held, so multiple references // to the same lock do not need to be accounted for. func (s *session) ReleaseAllAdvisoryLocks() int { var count int for lockName, lock := range s.advisoryLocks { lock.Close() count += lock.ReferenceCount() delete(s.advisoryLocks, lockName) infosync.DeleteInternalSession(lock.session) } return count } // GetExtensions returns the `*extension.SessionExtensions` object func (s *session) GetExtensions() *extension.SessionExtensions { return s.extensions } // SetExtensions sets the `*extension.SessionExtensions` object func (s *session) SetExtensions(extensions *extension.SessionExtensions) { s.extensions = extensions } // InSandBoxMode indicates that this session is in sandbox mode func (s *session) InSandBoxMode() bool { return s.sandBoxMode } // EnableSandBoxMode enable the sandbox mode. func (s *session) EnableSandBoxMode() { s.sandBoxMode = true } // DisableSandBoxMode enable the sandbox mode. func (s *session) DisableSandBoxMode() { s.sandBoxMode = false } // ParseWithParams4Test wrapper (s *session) ParseWithParams for test func ParseWithParams4Test(ctx context.Context, s Session, sql string, args ...interface{}) (ast.StmtNode, error) { return s.(*session).ParseWithParams(ctx, sql, args) } var _ sqlexec.RestrictedSQLExecutor = &session{} var _ sqlexec.SQLExecutor = &session{} // ExecRestrictedStmt implements RestrictedSQLExecutor interface. func (s *session) ExecRestrictedStmt(ctx context.Context, stmtNode ast.StmtNode, opts ...sqlexec.OptionFuncAlias) ( []chunk.Row, []*ast.ResultField, error) { defer pprof.SetGoroutineLabels(ctx) execOption := sqlexec.GetExecOption(opts) var se *session var clean func() var err error if execOption.UseCurSession { se, clean, err = s.useCurrentSession(execOption) } else { se, clean, err = s.getInternalSession(execOption) } if err != nil { return nil, nil, err } defer clean() startTime := time.Now() metrics.SessionRestrictedSQLCounter.Inc() ctx = context.WithValue(ctx, execdetails.StmtExecDetailKey, &execdetails.StmtExecDetails{}) ctx = context.WithValue(ctx, tikvutil.ExecDetailsKey, &tikvutil.ExecDetails{}) rs, err := se.ExecuteStmt(ctx, stmtNode) if err != nil { se.sessionVars.StmtCtx.AppendError(err) } if rs == nil { return nil, nil, err } defer func() { if closeErr := rs.Close(); closeErr != nil { err = closeErr } }() var rows []chunk.Row rows, err = drainRecordSet(ctx, se, rs, nil) if err != nil { return nil, nil, err } metrics.QueryDurationHistogram.WithLabelValues(metrics.LblInternal).Observe(time.Since(startTime).Seconds()) return rows, rs.Fields(), err } // ExecRestrictedStmt4Test wrapper `(s *session) ExecRestrictedStmt` for test. func ExecRestrictedStmt4Test(ctx context.Context, s Session, stmtNode ast.StmtNode, opts ...sqlexec.OptionFuncAlias) ( []chunk.Row, []*ast.ResultField, error) { ctx = kv.WithInternalSourceType(ctx, kv.InternalTxnOthers) return s.(*session).ExecRestrictedStmt(ctx, stmtNode, opts...) } // only set and clean session with execOption func (s *session) useCurrentSession(execOption sqlexec.ExecOption) (*session, func(), error) { var err error orgSnapshotInfoSchema, orgSnapshotTS := s.sessionVars.SnapshotInfoschema, s.sessionVars.SnapshotTS if execOption.SnapshotTS != 0 { if err = s.sessionVars.SetSystemVar(variable.TiDBSnapshot, strconv.FormatUint(execOption.SnapshotTS, 10)); err != nil { return nil, nil, err } s.sessionVars.SnapshotInfoschema, err = getSnapshotInfoSchema(s, execOption.SnapshotTS) if err != nil { return nil, nil, err } } prevStatsVer := s.sessionVars.AnalyzeVersion if execOption.AnalyzeVer != 0 { s.sessionVars.AnalyzeVersion = execOption.AnalyzeVer } prevAnalyzeSnapshot := s.sessionVars.EnableAnalyzeSnapshot if execOption.AnalyzeSnapshot != nil { s.sessionVars.EnableAnalyzeSnapshot = *execOption.AnalyzeSnapshot } prePruneMode := s.sessionVars.PartitionPruneMode.Load() if len(execOption.PartitionPruneMode) > 0 { s.sessionVars.PartitionPruneMode.Store(execOption.PartitionPruneMode) } prevSQL := s.sessionVars.StmtCtx.OriginalSQL prevStmtType := s.sessionVars.StmtCtx.StmtType prevTables := s.sessionVars.StmtCtx.Tables return s, func() { s.sessionVars.AnalyzeVersion = prevStatsVer s.sessionVars.EnableAnalyzeSnapshot = prevAnalyzeSnapshot if err := s.sessionVars.SetSystemVar(variable.TiDBSnapshot, ""); err != nil { logutil.BgLogger().Error("set tidbSnapshot error", zap.Error(err)) } s.sessionVars.SnapshotInfoschema = orgSnapshotInfoSchema s.sessionVars.SnapshotTS = orgSnapshotTS s.sessionVars.PartitionPruneMode.Store(prePruneMode) s.sessionVars.StmtCtx.OriginalSQL = prevSQL s.sessionVars.StmtCtx.StmtType = prevStmtType s.sessionVars.StmtCtx.Tables = prevTables s.sessionVars.MemTracker.Detach() }, nil } func (s *session) getInternalSession(execOption sqlexec.ExecOption) (*session, func(), error) { tmp, err := s.sysSessionPool().Get() if err != nil { return nil, nil, errors.Trace(err) } se := tmp.(*session) // The special session will share the `InspectionTableCache` with current session // if the current session in inspection mode. if cache := s.sessionVars.InspectionTableCache; cache != nil { se.sessionVars.InspectionTableCache = cache } if ok := s.sessionVars.OptimizerUseInvisibleIndexes; ok { se.sessionVars.OptimizerUseInvisibleIndexes = true } if execOption.SnapshotTS != 0 { if err := se.sessionVars.SetSystemVar(variable.TiDBSnapshot, strconv.FormatUint(execOption.SnapshotTS, 10)); err != nil { return nil, nil, err } se.sessionVars.SnapshotInfoschema, err = getSnapshotInfoSchema(s, execOption.SnapshotTS) if err != nil { return nil, nil, err } } prevStatsVer := se.sessionVars.AnalyzeVersion if execOption.AnalyzeVer != 0 { se.sessionVars.AnalyzeVersion = execOption.AnalyzeVer } prevAnalyzeSnapshot := se.sessionVars.EnableAnalyzeSnapshot if execOption.AnalyzeSnapshot != nil { se.sessionVars.EnableAnalyzeSnapshot = *execOption.AnalyzeSnapshot } prePruneMode := se.sessionVars.PartitionPruneMode.Load() if len(execOption.PartitionPruneMode) > 0 { se.sessionVars.PartitionPruneMode.Store(execOption.PartitionPruneMode) } return se, func() { se.sessionVars.AnalyzeVersion = prevStatsVer se.sessionVars.EnableAnalyzeSnapshot = prevAnalyzeSnapshot if err := se.sessionVars.SetSystemVar(variable.TiDBSnapshot, ""); err != nil { logutil.BgLogger().Error("set tidbSnapshot error", zap.Error(err)) } se.sessionVars.SnapshotInfoschema = nil se.sessionVars.SnapshotTS = 0 if !execOption.IgnoreWarning { if se != nil && se.GetSessionVars().StmtCtx.WarningCount() > 0 { warnings := se.GetSessionVars().StmtCtx.GetWarnings() s.GetSessionVars().StmtCtx.AppendWarnings(warnings) } } se.sessionVars.PartitionPruneMode.Store(prePruneMode) se.sessionVars.OptimizerUseInvisibleIndexes = false se.sessionVars.InspectionTableCache = nil se.sessionVars.MemTracker.Detach() s.sysSessionPool().Put(tmp) }, nil } func (s *session) withRestrictedSQLExecutor(ctx context.Context, opts []sqlexec.OptionFuncAlias, fn func(context.Context, *session) ([]chunk.Row, []*ast.ResultField, error)) ([]chunk.Row, []*ast.ResultField, error) { execOption := sqlexec.GetExecOption(opts) var se *session var clean func() var err error if execOption.UseCurSession { se, clean, err = s.useCurrentSession(execOption) } else { se, clean, err = s.getInternalSession(execOption) } if err != nil { return nil, nil, errors.Trace(err) } defer clean() if execOption.TrackSysProcID > 0 { err = execOption.TrackSysProc(execOption.TrackSysProcID, se) if err != nil { return nil, nil, errors.Trace(err) } // unTrack should be called before clean (return sys session) defer execOption.UnTrackSysProc(execOption.TrackSysProcID) } return fn(ctx, se) } func (s *session) ExecRestrictedSQL(ctx context.Context, opts []sqlexec.OptionFuncAlias, sql string, params ...interface{}) ([]chunk.Row, []*ast.ResultField, error) { return s.withRestrictedSQLExecutor(ctx, opts, func(ctx context.Context, se *session) ([]chunk.Row, []*ast.ResultField, error) { stmt, err := se.ParseWithParams(ctx, sql, params...) if err != nil { return nil, nil, errors.Trace(err) } defer pprof.SetGoroutineLabels(ctx) startTime := time.Now() metrics.SessionRestrictedSQLCounter.Inc() ctx = context.WithValue(ctx, execdetails.StmtExecDetailKey, &execdetails.StmtExecDetails{}) ctx = context.WithValue(ctx, tikvutil.ExecDetailsKey, &tikvutil.ExecDetails{}) rs, err := se.ExecuteInternalStmt(ctx, stmt) if err != nil { se.sessionVars.StmtCtx.AppendError(err) } if rs == nil { return nil, nil, err } defer func() { if closeErr := rs.Close(); closeErr != nil { err = closeErr } }() var rows []chunk.Row rows, err = drainRecordSet(ctx, se, rs, nil) if err != nil { return nil, nil, err } metrics.QueryDurationHistogram.WithLabelValues(metrics.LblInternal).Observe(time.Since(startTime).Seconds()) return rows, rs.Fields(), err }) } // ExecuteInternalStmt execute internal stmt func (s *session) ExecuteInternalStmt(ctx context.Context, stmtNode ast.StmtNode) (sqlexec.RecordSet, error) { origin := s.sessionVars.InRestrictedSQL s.sessionVars.InRestrictedSQL = true defer func() { s.sessionVars.InRestrictedSQL = origin // Restore the goroutine label by using the original ctx after execution is finished. pprof.SetGoroutineLabels(ctx) }() return s.ExecuteStmt(ctx, stmtNode) } func (s *session) ExecuteStmt(ctx context.Context, stmtNode ast.StmtNode) (sqlexec.RecordSet, error) { if span := opentracing.SpanFromContext(ctx); span != nil && span.Tracer() != nil { span1 := span.Tracer().StartSpan("session.ExecuteStmt", opentracing.ChildOf(span.Context())) defer span1.Finish() ctx = opentracing.ContextWithSpan(ctx, span1) } if err := s.PrepareTxnCtx(ctx); err != nil { return nil, err } if err := s.loadCommonGlobalVariablesIfNeeded(); err != nil { return nil, err } sessVars := s.sessionVars sessVars.StartTime = time.Now() // Some executions are done in compile stage, so we reset them before compile. if err := executor.ResetContextOfStmt(s, stmtNode); err != nil { return nil, err } normalizedSQL, digest := s.sessionVars.StmtCtx.SQLDigest() if topsqlstate.TopSQLEnabled() { s.sessionVars.StmtCtx.IsSQLRegistered.Store(true) ctx = topsql.AttachAndRegisterSQLInfo(ctx, normalizedSQL, digest, s.sessionVars.InRestrictedSQL) } if err := s.validateStatementReadOnlyInStaleness(stmtNode); err != nil { return nil, err } // Uncorrelated subqueries will execute once when building plan, so we reset process info before building plan. cmd32 := atomic.LoadUint32(&s.GetSessionVars().CommandValue) s.SetProcessInfo(stmtNode.Text(), time.Now(), byte(cmd32), 0) s.txn.onStmtStart(digest.String()) defer s.txn.onStmtEnd() if err := s.onTxnManagerStmtStartOrRetry(ctx, stmtNode); err != nil { return nil, err } failpoint.Inject("mockStmtSlow", func(val failpoint.Value) { if strings.Contains(stmtNode.Text(), "/* sleep */") { v, _ := val.(int) time.Sleep(time.Duration(v) * time.Millisecond) } }) stmtLabel := ast.GetStmtLabel(stmtNode) s.setRequestSource(ctx, stmtLabel, stmtNode) // Transform abstract syntax tree to a physical plan(stored in executor.ExecStmt). compiler := executor.Compiler{Ctx: s} stmt, err := compiler.Compile(ctx, stmtNode) if err != nil { s.rollbackOnError(ctx) // Only print log message when this SQL is from the user. // Mute the warning for internal SQLs. if !s.sessionVars.InRestrictedSQL { if !variable.ErrUnknownSystemVar.Equal(err) { logutil.Logger(ctx).Warn("compile SQL failed", zap.Error(err), zap.String("SQL", stmtNode.Text())) } } return nil, err } durCompile := time.Since(s.sessionVars.StartTime) s.GetSessionVars().DurationCompile = durCompile if s.isInternal() { sessionExecuteCompileDurationInternal.Observe(durCompile.Seconds()) } else { sessionExecuteCompileDurationGeneral.Observe(durCompile.Seconds()) } s.currentPlan = stmt.Plan if execStmt, ok := stmtNode.(*ast.ExecuteStmt); ok { if execStmt.Name == "" { // for exec-stmt on bin-protocol, ignore the plan detail in `show process` to gain performance benefits. s.currentPlan = nil } } // Execute the physical plan. logStmt(stmt, s) var recordSet sqlexec.RecordSet if stmt.PsStmt != nil { // point plan short path recordSet, err = stmt.PointGet(ctx) s.txn.changeToInvalid() } else { recordSet, err = runStmt(ctx, s, stmt) } if err != nil { if !errIsNoisy(err) { logutil.Logger(ctx).Warn("run statement failed", zap.Int64("schemaVersion", s.GetInfoSchema().SchemaMetaVersion()), zap.Error(err), zap.String("session", s.String())) } return recordSet, err } if !s.isInternal() && config.GetGlobalConfig().EnableTelemetry { telemetry.CurrentExecuteCount.Inc() tiFlashPushDown, tiFlashExchangePushDown := plannercore.IsTiFlashContained(stmt.Plan) if tiFlashPushDown { telemetry.CurrentTiFlashPushDownCount.Inc() } if tiFlashExchangePushDown { telemetry.CurrentTiFlashExchangePushDownCount.Inc() } } return recordSet, nil } func (s *session) onTxnManagerStmtStartOrRetry(ctx context.Context, node ast.StmtNode) error { if s.sessionVars.RetryInfo.Retrying { return sessiontxn.GetTxnManager(s).OnStmtRetry(ctx) } return sessiontxn.GetTxnManager(s).OnStmtStart(ctx, node) } func (s *session) validateStatementReadOnlyInStaleness(stmtNode ast.StmtNode) error { vars := s.GetSessionVars() if !vars.TxnCtx.IsStaleness && vars.TxnReadTS.PeakTxnReadTS() == 0 && !vars.EnableExternalTSRead || vars.InRestrictedSQL { return nil } errMsg := "only support read-only statement during read-only staleness transactions" node := stmtNode.(ast.Node) switch v := node.(type) { case *ast.SplitRegionStmt: return nil case *ast.SelectStmt: // select lock statement needs start a transaction which will be conflict to stale read, // we forbid select lock statement in stale read for now. if v.LockInfo != nil { return errors.New("select lock hasn't been supported in stale read yet") } if !planner.IsReadOnly(stmtNode, vars) { return errors.New(errMsg) } return nil case *ast.ExplainStmt, *ast.DoStmt, *ast.ShowStmt, *ast.SetOprStmt, *ast.ExecuteStmt, *ast.SetOprSelectList: if !planner.IsReadOnly(stmtNode, vars) { return errors.New(errMsg) } return nil default: } // covered DeleteStmt/InsertStmt/UpdateStmt/CallStmt/LoadDataStmt if _, ok := stmtNode.(ast.DMLNode); ok { return errors.New(errMsg) } return nil } // querySpecialKeys contains the keys of special query, the special query will handled by handleQuerySpecial method. var querySpecialKeys = []fmt.Stringer{ executor.LoadDataVarKey, executor.LoadStatsVarKey, executor.IndexAdviseVarKey, executor.PlanReplayerLoadVarKey, } func (s *session) hasQuerySpecial() bool { found := false s.mu.RLock() for _, k := range querySpecialKeys { v := s.mu.values[k] if v != nil { found = true break } } s.mu.RUnlock() return found } // runStmt executes the sqlexec.Statement and commit or rollback the current transaction. func runStmt(ctx context.Context, se *session, s sqlexec.Statement) (rs sqlexec.RecordSet, err error) { failpoint.Inject("assertTxnManagerInRunStmt", func() { sessiontxn.RecordAssert(se, "assertTxnManagerInRunStmt", true) if stmt, ok := s.(*executor.ExecStmt); ok { sessiontxn.AssertTxnManagerInfoSchema(se, stmt.InfoSchema) } }) if span := opentracing.SpanFromContext(ctx); span != nil && span.Tracer() != nil { span1 := span.Tracer().StartSpan("session.runStmt", opentracing.ChildOf(span.Context())) span1.LogKV("sql", s.OriginText()) defer span1.Finish() ctx = opentracing.ContextWithSpan(ctx, span1) } se.SetValue(sessionctx.QueryString, s.OriginText()) if _, ok := s.(*executor.ExecStmt).StmtNode.(ast.DDLNode); ok { se.SetValue(sessionctx.LastExecuteDDL, true) } else { se.ClearValue(sessionctx.LastExecuteDDL) } sessVars := se.sessionVars // Record diagnostic information for DML statements if stmt, ok := s.(*executor.ExecStmt).StmtNode.(ast.DMLNode); ok { // Keep the previous queryInfo for `show session_states` because the statement needs to encode it. if showStmt, ok := stmt.(*ast.ShowStmt); !ok || showStmt.Tp != ast.ShowSessionStates { defer func() { sessVars.LastQueryInfo = sessionstates.QueryInfo{ TxnScope: sessVars.CheckAndGetTxnScope(), StartTS: sessVars.TxnCtx.StartTS, ForUpdateTS: sessVars.TxnCtx.GetForUpdateTS(), } if err != nil { sessVars.LastQueryInfo.ErrMsg = err.Error() } }() } } // Save origTxnCtx here to avoid it reset in the transaction retry. origTxnCtx := sessVars.TxnCtx err = se.checkTxnAborted(s) if err != nil { return nil, err } rs, err = s.Exec(ctx) se.updateTelemetryMetric(s.(*executor.ExecStmt)) sessVars.TxnCtx.StatementCount++ if rs != nil { if se.GetSessionVars().StmtCtx.IsExplainAnalyzeDML { if !sessVars.InTxn() { se.StmtCommit(ctx) if err := se.CommitTxn(ctx); err != nil { return nil, err } } } return &execStmtResult{ RecordSet: rs, sql: s, se: se, }, err } err = finishStmt(ctx, se, err, s) if se.hasQuerySpecial() { // The special query will be handled later in handleQuerySpecial, // then should call the ExecStmt.FinishExecuteStmt to finish this statement. se.SetValue(ExecStmtVarKey, s.(*executor.ExecStmt)) } else { // If it is not a select statement or special query, we record its slow log here, // then it could include the transaction commit time. s.(*executor.ExecStmt).FinishExecuteStmt(origTxnCtx.StartTS, err, false) } return nil, err } // ExecStmtVarKeyType is a dummy type to avoid naming collision in context. type ExecStmtVarKeyType int // String defines a Stringer function for debugging and pretty printing. func (k ExecStmtVarKeyType) String() string { return "exec_stmt_var_key" } // ExecStmtVarKey is a variable key for ExecStmt. const ExecStmtVarKey ExecStmtVarKeyType = 0 // execStmtResult is the return value of ExecuteStmt and it implements the sqlexec.RecordSet interface. // Why we need a struct to wrap a RecordSet and provide another RecordSet? // This is because there are so many session state related things that definitely not belongs to the original // RecordSet, so this struct exists and RecordSet.Close() is overrided handle that. type execStmtResult struct { sqlexec.RecordSet se *session sql sqlexec.Statement } func (rs *execStmtResult) Close() error { se := rs.se if err := rs.RecordSet.Close(); err != nil { return finishStmt(context.Background(), se, err, rs.sql) } if err := resetCTEStorageMap(se); err != nil { return finishStmt(context.Background(), se, err, rs.sql) } return finishStmt(context.Background(), se, nil, rs.sql) } func resetCTEStorageMap(se *session) error { tmp := se.GetSessionVars().StmtCtx.CTEStorageMap if tmp == nil { // Close() is already called, so no need to reset. Such as TraceExec. return nil } storageMap, ok := tmp.(map[int]*executor.CTEStorages) if !ok { return errors.New("type assertion for CTEStorageMap failed") } for _, v := range storageMap { v.ResTbl.Lock() err1 := v.ResTbl.DerefAndClose() // Make sure we do not hold the lock for longer than necessary. v.ResTbl.Unlock() // No need to lock IterInTbl. err2 := v.IterInTbl.DerefAndClose() if err1 != nil { return err1 } if err2 != nil { return err2 } } se.GetSessionVars().StmtCtx.CTEStorageMap = nil return nil } // rollbackOnError makes sure the next statement starts a new transaction with the latest InfoSchema. func (s *session) rollbackOnError(ctx context.Context) { if !s.sessionVars.InTxn() { s.RollbackTxn(ctx) } } // PrepareStmt is used for executing prepare statement in binary protocol func (s *session) PrepareStmt(sql string) (stmtID uint32, paramCount int, fields []*ast.ResultField, err error) { if s.sessionVars.TxnCtx.InfoSchema == nil { // We don't need to create a transaction for prepare statement, just get information schema will do. s.sessionVars.TxnCtx.InfoSchema = domain.GetDomain(s).InfoSchema() } err = s.loadCommonGlobalVariablesIfNeeded() if err != nil { return } ctx := context.Background() // NewPrepareExec may need startTS to build the executor, for example prepare statement has subquery in int. // So we have to call PrepareTxnCtx here. if err = s.PrepareTxnCtx(ctx); err != nil { return } prepareStmt := &ast.PrepareStmt{SQLText: sql} if err = s.onTxnManagerStmtStartOrRetry(ctx, prepareStmt); err != nil { return } if err = sessiontxn.GetTxnManager(s).AdviseWarmup(); err != nil { return } prepareExec := executor.NewPrepareExec(s, sql) err = prepareExec.Next(ctx, nil) // Rollback even if err is nil. s.rollbackOnError(ctx) if err != nil { return } return prepareExec.ID, prepareExec.ParamCount, prepareExec.Fields, nil } // ExecutePreparedStmt executes a prepared statement. func (s *session) ExecutePreparedStmt(ctx context.Context, stmtID uint32, params []expression.Expression) (sqlexec.RecordSet, error) { prepStmt, err := s.sessionVars.GetPreparedStmtByID(stmtID) if err != nil { err = plannercore.ErrStmtNotFound logutil.Logger(ctx).Error("prepared statement not found", zap.Uint32("stmtID", stmtID)) return nil, err } stmt, ok := prepStmt.(*plannercore.PlanCacheStmt) if !ok { return nil, errors.Errorf("invalid PlanCacheStmt type") } execStmt := &ast.ExecuteStmt{ BinaryArgs: params, PrepStmt: stmt, } return s.ExecuteStmt(ctx, execStmt) } func (s *session) DropPreparedStmt(stmtID uint32) error { vars := s.sessionVars if _, ok := vars.PreparedStmts[stmtID]; !ok { return plannercore.ErrStmtNotFound } vars.RetryInfo.DroppedPreparedStmtIDs = append(vars.RetryInfo.DroppedPreparedStmtIDs, stmtID) return nil } func (s *session) Txn(active bool) (kv.Transaction, error) { if !active { return &s.txn, nil } _, err := sessiontxn.GetTxnManager(s).ActivateTxn() s.SetMemoryFootprintChangeHook() return &s.txn, err } func (s *session) SetValue(key fmt.Stringer, value interface{}) { s.mu.Lock() s.mu.values[key] = value s.mu.Unlock() } func (s *session) Value(key fmt.Stringer) interface{} { s.mu.RLock() value := s.mu.values[key] s.mu.RUnlock() return value } func (s *session) ClearValue(key fmt.Stringer) { s.mu.Lock() delete(s.mu.values, key) s.mu.Unlock() } type inCloseSession struct{} // Close function does some clean work when session end. // Close should release the table locks which hold by the session. func (s *session) Close() { // TODO: do clean table locks when session exited without execute Close. // TODO: do clean table locks when tidb-server was `kill -9`. if s.HasLockedTables() && config.TableLockEnabled() { if ds := config.TableLockDelayClean(); ds > 0 { time.Sleep(time.Duration(ds) * time.Millisecond) } lockedTables := s.GetAllTableLocks() err := domain.GetDomain(s).DDL().UnlockTables(s, lockedTables) if err != nil { logutil.BgLogger().Error("release table lock failed", zap.Uint64("conn", s.sessionVars.ConnectionID)) } } s.ReleaseAllAdvisoryLocks() if s.statsCollector != nil { s.statsCollector.Delete() } if s.idxUsageCollector != nil { s.idxUsageCollector.Delete() } telemetry.GlobalBuiltinFunctionsUsage.Collect(s.GetBuiltinFunctionUsage()) bindValue := s.Value(bindinfo.SessionBindInfoKeyType) if bindValue != nil { bindValue.(*bindinfo.SessionHandle).Close() } ctx := context.WithValue(context.TODO(), inCloseSession{}, struct{}{}) s.RollbackTxn(ctx) if s.sessionVars != nil { s.sessionVars.WithdrawAllPreparedStmt() } if s.stmtStats != nil { s.stmtStats.SetFinished() } s.ClearDiskFullOpt() if s.preparedPlanCache != nil { s.preparedPlanCache.Close() } } // GetSessionVars implements the context.Context interface. func (s *session) GetSessionVars() *variable.SessionVars { return s.sessionVars } func (s *session) AuthPluginForUser(user *auth.UserIdentity) (string, error) { pm := privilege.GetPrivilegeManager(s) authplugin, err := pm.GetAuthPluginForConnection(user.Username, user.Hostname) if err != nil { return "", err } return authplugin, nil } // Auth validates a user using an authentication string and salt. // If the password fails, it will keep trying other users until exhausted. // This means it can not be refactored to use MatchIdentity yet. func (s *session) Auth(user *auth.UserIdentity, authentication, salt []byte) error { hasPassword := "YES" if len(authentication) == 0 { hasPassword = "NO" } pm := privilege.GetPrivilegeManager(s) authUser, err := s.MatchIdentity(user.Username, user.Hostname) if err != nil { return privileges.ErrAccessDenied.FastGenByArgs(user.Username, user.Hostname, hasPassword) } // Check whether continuous login failure is enabled to lock the account. // If enabled, determine whether to unlock the account and notify TiDB to update the cache. enableAutoLock := pm.IsAccountAutoLockEnabled(authUser.Username, authUser.Hostname) if enableAutoLock { err = failedLoginTrackingBegin(s) if err != nil { return err } lockStatusChanged, err := verifyAccountAutoLock(s, authUser.Username, authUser.Hostname) if err != nil { rollbackErr := failedLoginTrackingRollback(s) if rollbackErr != nil { return rollbackErr } return err } err = failedLoginTrackingCommit(s) if err != nil { rollbackErr := failedLoginTrackingRollback(s) if rollbackErr != nil { return rollbackErr } return err } if lockStatusChanged { // Notification auto unlock. err = domain.GetDomain(s).NotifyUpdatePrivilege() if err != nil { return err } } } info, err := pm.ConnectionVerification(user, authUser.Username, authUser.Hostname, authentication, salt, s.sessionVars) if err != nil { if info.FailedDueToWrongPassword { // when user enables the account locking function for consecutive login failures, // the system updates the login failure count and determines whether to lock the account when authentication fails. if enableAutoLock { err := failedLoginTrackingBegin(s) if err != nil { return err } lockStatusChanged, passwordLocking, trackingErr := authFailedTracking(s, authUser.Username, authUser.Hostname) if trackingErr != nil { if rollBackErr := failedLoginTrackingRollback(s); rollBackErr != nil { return rollBackErr } return trackingErr } if err := failedLoginTrackingCommit(s); err != nil { if rollBackErr := failedLoginTrackingRollback(s); rollBackErr != nil { return rollBackErr } return err } if lockStatusChanged { // Notification auto lock. err := autolockAction(s, passwordLocking, authUser.Username, authUser.Hostname) if err != nil { return err } } } } return err } // If tidb_resource_control_enable is disabled, set resource group to empty if variable.EnableResourceControl.Load() { s.sessionVars.ResourceGroupName = strings.ToLower(info.ResourceGroupName) } else { s.sessionVars.ResourceGroupName = "" } if info.InSandBoxMode { // Enter sandbox mode, only execute statement for resetting password. s.EnableSandBoxMode() } if enableAutoLock { err := failedLoginTrackingBegin(s) if err != nil { return err } // The password is correct. If the account is not locked, the number of login failure statistics will be cleared. err = authSuccessClearCount(s, authUser.Username, authUser.Hostname) if err != nil { if rollBackErr := failedLoginTrackingRollback(s); rollBackErr != nil { return rollBackErr } return err } err = failedLoginTrackingCommit(s) if err != nil { if rollBackErr := failedLoginTrackingRollback(s); rollBackErr != nil { return rollBackErr } return err } } pm.AuthSuccess(authUser.Username, authUser.Hostname) user.AuthUsername = authUser.Username user.AuthHostname = authUser.Hostname s.sessionVars.User = user s.sessionVars.ActiveRoles = pm.GetDefaultRoles(user.AuthUsername, user.AuthHostname) return nil } func authSuccessClearCount(s *session, user string, host string) error { // Obtain accurate lock status and failure count information. passwordLocking, err := getFailedLoginUserAttributes(s, user, host) if err != nil { return err } // If the account is locked, it may be caused by the untimely update of the cache, // directly report the account lock. if passwordLocking.AutoAccountLocked { if passwordLocking.PasswordLockTimeDays == -1 { return privileges.GenerateAccountAutoLockErr(passwordLocking.FailedLoginAttempts, user, host, "unlimited", "unlimited") } lds := strconv.FormatInt(passwordLocking.PasswordLockTimeDays, 10) return privileges.GenerateAccountAutoLockErr(passwordLocking.FailedLoginAttempts, user, host, lds, lds) } if passwordLocking.FailedLoginCount != 0 { // If the number of account login failures is not zero, it will be updated to 0. passwordLockingJSON := privileges.BuildSuccessPasswordLockingJSON(passwordLocking.FailedLoginAttempts, passwordLocking.PasswordLockTimeDays) if passwordLockingJSON != "" { if err := s.passwordLocking(user, host, passwordLockingJSON); err != nil { return err } } } return nil } func verifyAccountAutoLock(s *session, user, host string) (bool, error) { pm := privilege.GetPrivilegeManager(s) // Use the cache to determine whether to unlock the account. // If the account needs to be unlocked, read the database information to determine whether // the account needs to be unlocked. Otherwise, an error message is displayed. lockStatusInMemory, err := pm.VerifyAccountAutoLockInMemory(user, host) if err != nil { return false, err } // If the lock status in the cache is Unlock, the automatic unlock is skipped. // If memory synchronization is slow and there is a lock in the database, it will be processed upon successful login. if !lockStatusInMemory { return false, nil } lockStatusChanged := false var plJSON string // After checking the cache, obtain the latest data from the database and determine // whether to automatically unlock the database to prevent repeated unlock errors. pl, err := getFailedLoginUserAttributes(s, user, host) if err != nil { return false, err } if pl.AutoAccountLocked { // If it is locked, need to check whether it can be automatically unlocked. lockTimeDay := pl.PasswordLockTimeDays if lockTimeDay == -1 { return false, privileges.GenerateAccountAutoLockErr(pl.FailedLoginAttempts, user, host, "unlimited", "unlimited") } lastChanged := pl.AutoLockedLastChanged d := time.Now().Unix() - lastChanged if d > lockTimeDay*24*60*60 { // Generate unlock json string. plJSON = privileges.BuildPasswordLockingJSON(pl.FailedLoginAttempts, pl.PasswordLockTimeDays, "N", 0, time.Now().Format(time.UnixDate)) } else { lds := strconv.FormatInt(lockTimeDay, 10) rds := strconv.FormatInt(int64(math.Ceil(float64(lockTimeDay)-float64(d)/(24*60*60))), 10) return false, privileges.GenerateAccountAutoLockErr(pl.FailedLoginAttempts, user, host, lds, rds) } } if plJSON != "" { lockStatusChanged = true if err = s.passwordLocking(user, host, plJSON); err != nil { return false, err } } return lockStatusChanged, nil } func authFailedTracking(s *session, user string, host string) (bool, *privileges.PasswordLocking, error) { // Obtain the number of consecutive password login failures. passwordLocking, err := getFailedLoginUserAttributes(s, user, host) if err != nil { return false, nil, err } // Consecutive wrong password login failure times +1, // If the lock condition is satisfied, the lock status is updated and the update cache is notified. lockStatusChanged, err := userAutoAccountLocked(s, user, host, passwordLocking) if err != nil { return false, nil, err } return lockStatusChanged, passwordLocking, nil } func autolockAction(s *session, passwordLocking *privileges.PasswordLocking, user, host string) error { // Don't want to update the cache frequently, and only trigger the update cache when the lock status is updated. err := domain.GetDomain(s).NotifyUpdatePrivilege() if err != nil { return err } // The number of failed login attempts reaches FAILED_LOGIN_ATTEMPTS. // An error message is displayed indicating permission denial and account lock. if passwordLocking.PasswordLockTimeDays == -1 { return privileges.GenerateAccountAutoLockErr(passwordLocking.FailedLoginAttempts, user, host, "unlimited", "unlimited") } lds := strconv.FormatInt(passwordLocking.PasswordLockTimeDays, 10) return privileges.GenerateAccountAutoLockErr(passwordLocking.FailedLoginAttempts, user, host, lds, lds) } func (s *session) passwordLocking(user string, host string, newAttributesStr string) error { sql := new(strings.Builder) sqlexec.MustFormatSQL(sql, "UPDATE %n.%n SET ", mysql.SystemDB, mysql.UserTable) sqlexec.MustFormatSQL(sql, "user_attributes=json_merge_patch(coalesce(user_attributes, '{}'), %?)", newAttributesStr) sqlexec.MustFormatSQL(sql, " WHERE Host=%? and User=%?;", host, user) ctx := kv.WithInternalSourceType(context.Background(), kv.InternalTxnPrivilege) _, err := s.ExecuteInternal(ctx, sql.String()) return err } func failedLoginTrackingBegin(s *session) error { ctx := kv.WithInternalSourceType(context.Background(), kv.InternalTxnPrivilege) _, err := s.ExecuteInternal(ctx, "BEGIN PESSIMISTIC") return err } func failedLoginTrackingCommit(s *session) error { ctx := kv.WithInternalSourceType(context.Background(), kv.InternalTxnPrivilege) _, err := s.ExecuteInternal(ctx, "COMMIT") if err != nil { _, rollBackErr := s.ExecuteInternal(ctx, "ROLLBACK") if rollBackErr != nil { return rollBackErr } } return err } func failedLoginTrackingRollback(s *session) error { ctx := kv.WithInternalSourceType(context.Background(), kv.InternalTxnPrivilege) _, err := s.ExecuteInternal(ctx, "ROLLBACK") return err } // getFailedLoginUserAttributes queries the exact number of consecutive password login failures (concurrency is not allowed). func getFailedLoginUserAttributes(s *session, user string, host string) (*privileges.PasswordLocking, error) { passwordLocking := &privileges.PasswordLocking{} ctx := kv.WithInternalSourceType(context.Background(), kv.InternalTxnPrivilege) rs, err := s.ExecuteInternal(ctx, `SELECT user_attributes from mysql.user WHERE USER = %? AND HOST = %? for update`, user, host) if err != nil { return passwordLocking, err } defer func() { if closeErr := rs.Close(); closeErr != nil { err = closeErr } }() req := rs.NewChunk(nil) iter := chunk.NewIterator4Chunk(req) err = rs.Next(ctx, req) if err != nil { return passwordLocking, err } if req.NumRows() == 0 { return passwordLocking, fmt.Errorf("user_attributes by `%s`@`%s` not found", user, host) } row := iter.Begin() if !row.IsNull(0) { passwordLockingJSON := row.GetJSON(0) return passwordLocking, passwordLocking.ParseJSON(passwordLockingJSON) } return passwordLocking, fmt.Errorf("user_attributes by `%s`@`%s` not found", user, host) } func userAutoAccountLocked(s *session, user string, host string, pl *privileges.PasswordLocking) (bool, error) { // Indicates whether the user needs to update the lock status change. lockStatusChanged := false // The number of consecutive login failures is stored in the database. // If the current login fails, one is added to the number of consecutive login failures // stored in the database to determine whether the user needs to be locked and the number of update failures. failedLoginCount := pl.FailedLoginCount + 1 // If the cache is not updated, but it is already locked, it will report that the account is locked. if pl.AutoAccountLocked { if pl.PasswordLockTimeDays == -1 { return false, privileges.GenerateAccountAutoLockErr(pl.FailedLoginAttempts, user, host, "unlimited", "unlimited") } lds := strconv.FormatInt(pl.PasswordLockTimeDays, 10) return false, privileges.GenerateAccountAutoLockErr(pl.FailedLoginAttempts, user, host, lds, lds) } autoAccountLocked := "N" autoLockedLastChanged := "" if pl.FailedLoginAttempts == 0 || pl.PasswordLockTimeDays == 0 { return false, nil } if failedLoginCount >= pl.FailedLoginAttempts { autoLockedLastChanged = time.Now().Format(time.UnixDate) autoAccountLocked = "Y" lockStatusChanged = true } newAttributesStr := privileges.BuildPasswordLockingJSON(pl.FailedLoginAttempts, pl.PasswordLockTimeDays, autoAccountLocked, failedLoginCount, autoLockedLastChanged) if newAttributesStr != "" { return lockStatusChanged, s.passwordLocking(user, host, newAttributesStr) } return lockStatusChanged, nil } // MatchIdentity finds the matching username + password in the MySQL privilege tables // for a username + hostname, since MySQL can have wildcards. func (s *session) MatchIdentity(username, remoteHost string) (*auth.UserIdentity, error) { pm := privilege.GetPrivilegeManager(s) var success bool var skipNameResolve bool var user = &auth.UserIdentity{} varVal, err := s.GetSessionVars().GlobalVarsAccessor.GetGlobalSysVar(variable.SkipNameResolve) if err == nil && variable.TiDBOptOn(varVal) { skipNameResolve = true } user.Username, user.Hostname, success = pm.MatchIdentity(username, remoteHost, skipNameResolve) if success { return user, nil } // This error will not be returned to the user, access denied will be instead return nil, fmt.Errorf("could not find matching user in MatchIdentity: %s, %s", username, remoteHost) } // AuthWithoutVerification is required by the ResetConnection RPC func (s *session) AuthWithoutVerification(user *auth.UserIdentity) bool { pm := privilege.GetPrivilegeManager(s) authUser, err := s.MatchIdentity(user.Username, user.Hostname) if err != nil { return false } if pm.GetAuthWithoutVerification(authUser.Username, authUser.Hostname) { user.AuthUsername = authUser.Username user.AuthHostname = authUser.Hostname s.sessionVars.User = user s.sessionVars.ActiveRoles = pm.GetDefaultRoles(user.AuthUsername, user.AuthHostname) return true } return false } // RefreshVars implements the sessionctx.Context interface. func (s *session) RefreshVars(ctx context.Context) error { pruneMode, err := s.GetSessionVars().GlobalVarsAccessor.GetGlobalSysVar(variable.TiDBPartitionPruneMode) if err != nil { return err } s.sessionVars.PartitionPruneMode.Store(pruneMode) return nil } // SetSessionStatesHandler implements the Session.SetSessionStatesHandler interface. func (s *session) SetSessionStatesHandler(stateType sessionstates.SessionStateType, handler sessionctx.SessionStatesHandler) { s.sessionStatesHandlers[stateType] = handler } // CreateSession4Test creates a new session environment for test. func CreateSession4Test(store kv.Storage) (Session, error) { se, err := CreateSession4TestWithOpt(store, nil) if err == nil { // Cover both chunk rpc encoding and default encoding. // nolint:gosec if rand.Intn(2) == 0 { se.GetSessionVars().EnableChunkRPC = false } else { se.GetSessionVars().EnableChunkRPC = true } } return se, err } // Opt describes the option for creating session type Opt struct { PreparedPlanCache sessionctx.PlanCache } // CreateSession4TestWithOpt creates a new session environment for test. func CreateSession4TestWithOpt(store kv.Storage, opt *Opt) (Session, error) { s, err := CreateSessionWithOpt(store, opt) if err == nil { // initialize session variables for test. s.GetSessionVars().InitChunkSize = 2 s.GetSessionVars().MaxChunkSize = 32 s.GetSessionVars().MinPagingSize = variable.DefMinPagingSize s.GetSessionVars().EnablePaging = variable.DefTiDBEnablePaging err = s.GetSessionVars().SetSystemVarWithoutValidation(variable.CharacterSetConnection, "utf8mb4") } return s, err } // CreateSession creates a new session environment. func CreateSession(store kv.Storage) (Session, error) { return CreateSessionWithOpt(store, nil) } // CreateSessionWithOpt creates a new session environment with option. // Use default option if opt is nil. func CreateSessionWithOpt(store kv.Storage, opt *Opt) (Session, error) { s, err := createSessionWithOpt(store, opt) if err != nil { return nil, err } // Add auth here. do, err := domap.Get(store) if err != nil { return nil, err } extensions, err := extension.GetExtensions() if err != nil { return nil, err } pm := privileges.NewUserPrivileges(do.PrivilegeHandle(), extensions) privilege.BindPrivilegeManager(s, pm) // Add stats collector, and it will be freed by background stats worker // which periodically updates stats using the collected data. if do.StatsHandle() != nil && do.StatsUpdating() { s.statsCollector = do.StatsHandle().NewSessionStatsCollector() if GetIndexUsageSyncLease() > 0 { s.idxUsageCollector = do.StatsHandle().NewSessionIndexUsageCollector() } } return s, nil } // loadCollationParameter loads collation parameter from mysql.tidb func loadCollationParameter(ctx context.Context, se *session) (bool, error) { para, err := se.getTableValue(ctx, mysql.TiDBTable, tidbNewCollationEnabled) if err != nil { return false, err } if para == varTrue { return true, nil } else if para == varFalse { return false, nil } logutil.BgLogger().Warn( "Unexpected value of 'new_collation_enabled' in 'mysql.tidb', use 'False' instead", zap.String("value", para)) return false, nil } type tableBasicInfo struct { SQL string id int64 } var ( errResultIsEmpty = dbterror.ClassExecutor.NewStd(errno.ErrResultIsEmpty) // DDLJobTables is a list of tables definitions used in concurrent DDL. DDLJobTables = []tableBasicInfo{ {ddl.JobTableSQL, ddl.JobTableID}, {ddl.ReorgTableSQL, ddl.ReorgTableID}, {ddl.HistoryTableSQL, ddl.HistoryTableID}, } // BackfillTables is a list of tables definitions used in dist reorg DDL. BackfillTables = []tableBasicInfo{ {ddl.BackfillTableSQL, ddl.BackfillTableID}, {ddl.BackfillHistoryTableSQL, ddl.BackfillHistoryTableID}, } mdlTable = "create table mysql.tidb_mdl_info(job_id BIGINT NOT NULL PRIMARY KEY, version BIGINT NOT NULL, table_ids text(65535));" ) func splitAndScatterTable(store kv.Storage, tableIDs []int64) { if s, ok := store.(kv.SplittableStore); ok && atomic.LoadUint32(&ddl.EnableSplitTableRegion) == 1 { ctxWithTimeout, cancel := context.WithTimeout(context.Background(), variable.DefWaitSplitRegionTimeout*time.Second) var regionIDs []uint64 for _, id := range tableIDs { regionIDs = append(regionIDs, ddl.SplitRecordRegion(ctxWithTimeout, s, id, variable.DefTiDBScatterRegion)) } if variable.DefTiDBScatterRegion { ddl.WaitScatterRegionFinish(ctxWithTimeout, s, regionIDs...) } cancel() } } // InitDDLJobTables is to create tidb_ddl_job, tidb_ddl_reorg, tidb_ddl_history, tidb_ddl_backfill and tidb_ddl_backfill_history. func InitDDLJobTables(store kv.Storage) error { return kv.RunInNewTxn(kv.WithInternalSourceType(context.Background(), kv.InternalTxnDDL), store, true, func(ctx context.Context, txn kv.Transaction) error { t := meta.NewMeta(txn) exists, err := t.CheckDDLTableExists() if err != nil { return errors.Trace(err) } dbID, err := t.CreateMySQLDatabaseIfNotExists() if err != nil { return err } if exists { return initBackfillJobTables(store, t, dbID) } if err = createAndSplitTables(store, t, dbID, DDLJobTables); err != nil { return err } if err = initBackfillJobTables(store, t, dbID); err != nil { return err } return t.SetDDLTables() }) } // initBackfillJobTables is to create tidb_ddl_backfill and tidb_ddl_backfill_history. func initBackfillJobTables(store kv.Storage, t *meta.Meta, dbID int64) error { tblExist, err := t.CheckTableExists(dbID, BackfillTables[0].id) if err != nil || tblExist { return errors.Trace(err) } return createAndSplitTables(store, t, dbID, BackfillTables) } func createAndSplitTables(store kv.Storage, t *meta.Meta, dbID int64, tables []tableBasicInfo) error { tableIDs := make([]int64, 0, len(tables)) for _, tbl := range tables { tableIDs = append(tableIDs, tbl.id) } splitAndScatterTable(store, tableIDs) p := parser.New() for _, tbl := range tables { stmt, err := p.ParseOneStmt(tbl.SQL, "", "") if err != nil { return errors.Trace(err) } tblInfo, err := ddl.BuildTableInfoFromAST(stmt.(*ast.CreateTableStmt)) if err != nil { return errors.Trace(err) } tblInfo.State = model.StatePublic tblInfo.ID = tbl.id tblInfo.UpdateTS = t.StartTS err = t.CreateTableOrView(dbID, tblInfo) if err != nil { return errors.Trace(err) } } return nil } // InitMDLTable is to create tidb_mdl_info, which is used for metadata lock. func InitMDLTable(store kv.Storage) error { return kv.RunInNewTxn(kv.WithInternalSourceType(context.Background(), kv.InternalTxnDDL), store, true, func(ctx context.Context, txn kv.Transaction) error { t := meta.NewMeta(txn) exists, err := t.CheckMDLTableExists() if err != nil || exists { return errors.Trace(err) } dbID, err := t.CreateMySQLDatabaseIfNotExists() if err != nil { return err } splitAndScatterTable(store, []int64{ddl.MDLTableID}) p := parser.New() stmt, err := p.ParseOneStmt(mdlTable, "", "") if err != nil { return errors.Trace(err) } tblInfo, err := ddl.BuildTableInfoFromAST(stmt.(*ast.CreateTableStmt)) if err != nil { return errors.Trace(err) } tblInfo.State = model.StatePublic tblInfo.ID = ddl.MDLTableID tblInfo.UpdateTS = t.StartTS err = t.CreateTableOrView(dbID, tblInfo) if err != nil { return errors.Trace(err) } return t.SetMDLTables() }) } // InitMDLVariableForBootstrap initializes the metadata lock variable. func InitMDLVariableForBootstrap(store kv.Storage) error { err := kv.RunInNewTxn(kv.WithInternalSourceType(context.Background(), kv.InternalTxnDDL), store, true, func(ctx context.Context, txn kv.Transaction) error { t := meta.NewMeta(txn) return t.SetMetadataLock(true) }) if err != nil { return err } variable.EnableMDL.Store(true) return nil } // InitMDLVariableForUpgrade initializes the metadata lock variable. func InitMDLVariableForUpgrade(store kv.Storage) (bool, error) { isNull := false enable := false var err error err = kv.RunInNewTxn(kv.WithInternalSourceType(context.Background(), kv.InternalTxnDDL), store, true, func(ctx context.Context, txn kv.Transaction) error { t := meta.NewMeta(txn) enable, isNull, err = t.GetMetadataLock() if err != nil { return err } return nil }) if isNull || !enable { variable.EnableMDL.Store(false) } else { variable.EnableMDL.Store(true) } return isNull, err } // InitMDLVariable initializes the metadata lock variable. func InitMDLVariable(store kv.Storage) error { isNull := false enable := false var err error err = kv.RunInNewTxn(kv.WithInternalSourceType(context.Background(), kv.InternalTxnDDL), store, true, func(ctx context.Context, txn kv.Transaction) error { t := meta.NewMeta(txn) enable, isNull, err = t.GetMetadataLock() if err != nil { return err } if isNull { // Workaround for version: nightly-2022-11-07 to nightly-2022-11-17. enable = true logutil.BgLogger().Warn("metadata lock is null") err = t.SetMetadataLock(true) if err != nil { return err } } return nil }) variable.EnableMDL.Store(enable) return err } // BootstrapSession runs the first time when the TiDB server start. func BootstrapSession(store kv.Storage) (*domain.Domain, error) { ctx := kv.WithInternalSourceType(context.Background(), kv.InternalTxnBootstrap) cfg := config.GetGlobalConfig() if len(cfg.Instance.PluginLoad) > 0 { err := plugin.Load(context.Background(), plugin.Config{ Plugins: strings.Split(cfg.Instance.PluginLoad, ","), PluginDir: cfg.Instance.PluginDir, }) if err != nil { return nil, err } } err := InitDDLJobTables(store) if err != nil { return nil, err } err = InitMDLTable(store) if err != nil { return nil, err } ver := getStoreBootstrapVersion(store) if ver == notBootstrapped { runInBootstrapSession(store, bootstrap) } else if ver < currentBootstrapVersion { runInBootstrapSession(store, upgrade) } else { err = InitMDLVariable(store) if err != nil { return nil, err } } analyzeConcurrencyQuota := int(config.GetGlobalConfig().Performance.AnalyzePartitionConcurrencyQuota) concurrency := int(config.GetGlobalConfig().Performance.StatsLoadConcurrency) ses, err := createSessions(store, 10) if err != nil { return nil, err } ses[0].GetSessionVars().InRestrictedSQL = true // get system tz from mysql.tidb tz, err := ses[0].getTableValue(ctx, mysql.TiDBTable, tidbSystemTZ) if err != nil { return nil, err } timeutil.SetSystemTZ(tz) // get the flag from `mysql`.`tidb` which indicating if new collations are enabled. newCollationEnabled, err := loadCollationParameter(ctx, ses[0]) if err != nil { return nil, err } collate.SetNewCollationEnabledForTest(newCollationEnabled) // To deal with the location partition failure caused by inconsistent NewCollationEnabled values(see issue #32416). rebuildAllPartitionValueMapAndSorted(ses[0]) dom := domain.GetDomain(ses[0]) // We should make the load bind-info loop before other loops which has internal SQL. // Because the internal SQL may access the global bind-info handler. As the result, the data race occurs here as the // LoadBindInfoLoop inits global bind-info handler. err = dom.LoadBindInfoLoop(ses[1], ses[2]) if err != nil { return nil, err } if !config.GetGlobalConfig().Security.SkipGrantTable { err = dom.LoadPrivilegeLoop(ses[3]) if err != nil { return nil, err } } // Rebuild sysvar cache in a loop err = dom.LoadSysVarCacheLoop(ses[4]) if err != nil { return nil, err } if config.GetGlobalConfig().DisaggregatedTiFlash { // Invalid client-go tiflash_compute store cache if necessary. err = dom.WatchTiFlashComputeNodeChange() if err != nil { return nil, err } } if err = extensionimpl.Bootstrap(context.Background(), dom); err != nil { return nil, err } if len(cfg.Instance.PluginLoad) > 0 { err := plugin.Init(context.Background(), plugin.Config{EtcdClient: dom.GetEtcdClient()}) if err != nil { return nil, err } } err = executor.LoadExprPushdownBlacklist(ses[5]) if err != nil { return nil, err } err = executor.LoadOptRuleBlacklist(ctx, ses[5]) if err != nil { return nil, err } if dom.GetEtcdClient() != nil { // We only want telemetry data in production-like clusters. When TiDB is deployed over other engines, // for example, unistore engine (used for local tests), we just skip it. Its etcd client is nil. if config.GetGlobalConfig().EnableTelemetry { // There is no way to turn telemetry on with global variable `tidb_enable_telemetry` // when it is disabled in config. See IsTelemetryEnabled function in telemetry/telemetry.go go func() { dom.TelemetryReportLoop(ses[5]) dom.TelemetryRotateSubWindowLoop(ses[5]) }() } } planReplayerWorkerCnt := config.GetGlobalConfig().Performance.PlanReplayerDumpWorkerConcurrency planReplayerWorkersSctx := make([]sessionctx.Context, planReplayerWorkerCnt) pworkerSes, err := createSessions(store, int(planReplayerWorkerCnt)) if err != nil { return nil, err } for i := 0; i < int(planReplayerWorkerCnt); i++ { planReplayerWorkersSctx[i] = pworkerSes[i] } // setup plan replayer handle dom.SetupPlanReplayerHandle(ses[6], planReplayerWorkersSctx) dom.StartPlanReplayerHandle() // setup dumpFileGcChecker dom.SetupDumpFileGCChecker(ses[7]) dom.DumpFileGcCheckerLoop() // setup historical stats worker dom.SetupHistoricalStatsWorker(ses[8]) dom.StartHistoricalStatsWorker() if runBootstrapSQLFile { pm := &privileges.UserPrivileges{ Handle: dom.PrivilegeHandle(), } privilege.BindPrivilegeManager(ses[9], pm) doBootstrapSQLFile(ses[9]) } // A sub context for update table stats, and other contexts for concurrent stats loading. cnt := 1 + concurrency syncStatsCtxs, err := createSessions(store, cnt) if err != nil { return nil, err } subCtxs := make([]sessionctx.Context, cnt) for i := 0; i < cnt; i++ { subCtxs[i] = sessionctx.Context(syncStatsCtxs[i]) } initStatsCtx, err := createSession(store) if err != nil { return nil, err } if err = dom.LoadAndUpdateStatsLoop(subCtxs, initStatsCtx); err != nil { return nil, err } // start TTL job manager after setup stats collector // because TTL could modify a lot of columns, and need to trigger auto analyze ttlworker.AttachStatsCollector = func(s sqlexec.SQLExecutor) sqlexec.SQLExecutor { if s, ok := s.(*session); ok { return attachStatsCollector(s, dom) } return s } ttlworker.DetachStatsCollector = func(s sqlexec.SQLExecutor) sqlexec.SQLExecutor { if s, ok := s.(*session); ok { return detachStatsCollector(s) } return s } dom.StartTTLJobManager() analyzeCtxs, err := createSessions(store, analyzeConcurrencyQuota) if err != nil { return nil, err } subCtxs2 := make([]sessionctx.Context, analyzeConcurrencyQuota) for i := 0; i < analyzeConcurrencyQuota; i++ { subCtxs2[i] = analyzeCtxs[i] } dom.SetupAnalyzeExec(subCtxs2) dom.LoadSigningCertLoop(cfg.Security.SessionTokenSigningCert, cfg.Security.SessionTokenSigningKey) if raw, ok := store.(kv.EtcdBackend); ok { err = raw.StartGCWorker() if err != nil { return nil, err } } return dom, err } // GetDomain gets the associated domain for store. func GetDomain(store kv.Storage) (*domain.Domain, error) { return domap.Get(store) } // runInBootstrapSession create a special session for bootstrap to run. // If no bootstrap and storage is remote, we must use a little lease time to // bootstrap quickly, after bootstrapped, we will reset the lease time. // TODO: Using a bootstrap tool for doing this may be better later. func runInBootstrapSession(store kv.Storage, bootstrap func(Session)) { s, err := createSession(store) if err != nil { // Bootstrap fail will cause program exit. logutil.BgLogger().Fatal("createSession error", zap.Error(err)) } // For the bootstrap SQLs, the following variables should be compatible with old TiDB versions. s.sessionVars.EnableClusteredIndex = variable.ClusteredIndexDefModeIntOnly s.SetValue(sessionctx.Initing, true) bootstrap(s) finishBootstrap(store) s.ClearValue(sessionctx.Initing) dom := domain.GetDomain(s) dom.Close() domap.Delete(store) } func createSessions(store kv.Storage, cnt int) ([]*session, error) { ses := make([]*session, cnt) for i := 0; i < cnt; i++ { se, err := createSession(store) if err != nil { return nil, err } ses[i] = se } return ses, nil } // createSession creates a new session. // Please note that such a session is not tracked by the internal session list. // This means the min ts reporter is not aware of it and may report a wrong min start ts. // In most cases you should use a session pool in domain instead. func createSession(store kv.Storage) (*session, error) { return createSessionWithOpt(store, nil) } func createSessionWithOpt(store kv.Storage, opt *Opt) (*session, error) { dom, err := domap.Get(store) if err != nil { return nil, err } s := &session{ store: store, ddlOwnerManager: dom.DDL().OwnerManager(), client: store.GetClient(), mppClient: store.GetMPPClient(), stmtStats: stmtstats.CreateStatementStats(), sessionStatesHandlers: make(map[sessionstates.SessionStateType]sessionctx.SessionStatesHandler), } s.sessionVars = variable.NewSessionVars(s) s.functionUsageMu.builtinFunctionUsage = make(telemetry.BuiltinFunctionsUsage) if opt != nil && opt.PreparedPlanCache != nil { s.preparedPlanCache = opt.PreparedPlanCache } s.mu.values = make(map[fmt.Stringer]interface{}) s.lockedTables = make(map[int64]model.TableLockTpInfo) s.advisoryLocks = make(map[string]*advisoryLock) domain.BindDomain(s, dom) // session implements variable.GlobalVarAccessor. Bind it to ctx. s.sessionVars.GlobalVarsAccessor = s s.sessionVars.BinlogClient = binloginfo.GetPumpsClient() s.txn.init() sessionBindHandle := bindinfo.NewSessionBindHandle() s.SetValue(bindinfo.SessionBindInfoKeyType, sessionBindHandle) s.SetSessionStatesHandler(sessionstates.StateBinding, sessionBindHandle) return s, nil } // attachStatsCollector attaches the stats collector in the dom for the session func attachStatsCollector(s *session, dom *domain.Domain) *session { if dom.StatsHandle() != nil && dom.StatsUpdating() { s.statsCollector = dom.StatsHandle().NewSessionStatsCollector() if GetIndexUsageSyncLease() > 0 { s.idxUsageCollector = dom.StatsHandle().NewSessionIndexUsageCollector() } } return s } // detachStatsCollector removes the stats collector in the session func detachStatsCollector(s *session) *session { s.statsCollector = nil s.idxUsageCollector = nil return s } // CreateSessionWithDomain creates a new Session and binds it with a Domain. // We need this because when we start DDL in Domain, the DDL need a session // to change some system tables. But at that time, we have been already in // a lock context, which cause we can't call createSession directly. func CreateSessionWithDomain(store kv.Storage, dom *domain.Domain) (*session, error) { s := &session{ store: store, sessionVars: variable.NewSessionVars(nil), client: store.GetClient(), mppClient: store.GetMPPClient(), stmtStats: stmtstats.CreateStatementStats(), sessionStatesHandlers: make(map[sessionstates.SessionStateType]sessionctx.SessionStatesHandler), } s.functionUsageMu.builtinFunctionUsage = make(telemetry.BuiltinFunctionsUsage) s.mu.values = make(map[fmt.Stringer]interface{}) s.lockedTables = make(map[int64]model.TableLockTpInfo) domain.BindDomain(s, dom) // session implements variable.GlobalVarAccessor. Bind it to ctx. s.sessionVars.GlobalVarsAccessor = s s.txn.init() return s, nil } const ( notBootstrapped = 0 ) func getStoreBootstrapVersion(store kv.Storage) int64 { storeBootstrappedLock.Lock() defer storeBootstrappedLock.Unlock() // check in memory _, ok := storeBootstrapped[store.UUID()] if ok { return currentBootstrapVersion } var ver int64 // check in kv store ctx := kv.WithInternalSourceType(context.Background(), kv.InternalTxnBootstrap) err := kv.RunInNewTxn(ctx, store, false, func(ctx context.Context, txn kv.Transaction) error { var err error t := meta.NewMeta(txn) ver, err = t.GetBootstrapVersion() return err }) if err != nil { logutil.BgLogger().Fatal("check bootstrapped failed", zap.Error(err)) } if ver > notBootstrapped { // here mean memory is not ok, but other server has already finished it storeBootstrapped[store.UUID()] = true } return ver } func finishBootstrap(store kv.Storage) { setStoreBootstrapped(store.UUID()) ctx := kv.WithInternalSourceType(context.Background(), kv.InternalTxnBootstrap) err := kv.RunInNewTxn(ctx, store, true, func(ctx context.Context, txn kv.Transaction) error { t := meta.NewMeta(txn) err := t.FinishBootstrap(currentBootstrapVersion) return err }) if err != nil { logutil.BgLogger().Fatal("finish bootstrap failed", zap.Error(err)) } } const quoteCommaQuote = "', '" // loadCommonGlobalVariablesIfNeeded loads and applies commonly used global variables for the session. func (s *session) loadCommonGlobalVariablesIfNeeded() error { vars := s.sessionVars if vars.CommonGlobalLoaded { return nil } if s.Value(sessionctx.Initing) != nil { // When running bootstrap or upgrade, we should not access global storage. return nil } vars.CommonGlobalLoaded = true // Deep copy sessionvar cache sessionCache, err := domain.GetDomain(s).GetSessionCache() if err != nil { return err } for varName, varVal := range sessionCache { if _, ok := vars.GetSystemVar(varName); !ok { err = vars.SetSystemVarWithRelaxedValidation(varName, varVal) if err != nil { if variable.ErrUnknownSystemVar.Equal(err) { continue // sessionCache is stale; sysvar has likely been unregistered } return err } } } // when client set Capability Flags CLIENT_INTERACTIVE, init wait_timeout with interactive_timeout if vars.ClientCapability&mysql.ClientInteractive > 0 { if varVal, ok := vars.GetSystemVar(variable.InteractiveTimeout); ok { if err := vars.SetSystemVar(variable.WaitTimeout, varVal); err != nil { return err } } } return nil } // PrepareTxnCtx begins a transaction, and creates a new transaction context. // It is called before we execute a sql query. func (s *session) PrepareTxnCtx(ctx context.Context) error { s.currentCtx = ctx if s.txn.validOrPending() { return nil } txnMode := ast.Optimistic if !s.sessionVars.IsAutocommit() || config.GetGlobalConfig().PessimisticTxn.PessimisticAutoCommit.Load() { if s.sessionVars.TxnMode == ast.Pessimistic { txnMode = ast.Pessimistic } } if s.sessionVars.RetryInfo.Retrying { txnMode = ast.Pessimistic } return sessiontxn.GetTxnManager(s).EnterNewTxn(ctx, &sessiontxn.EnterNewTxnRequest{ Type: sessiontxn.EnterNewTxnBeforeStmt, TxnMode: txnMode, }) } // PrepareTSFuture uses to try to get ts future. func (s *session) PrepareTSFuture(ctx context.Context, future oracle.Future, scope string) error { if s.txn.Valid() { return errors.New("cannot prepare ts future when txn is valid") } failpoint.Inject("assertTSONotRequest", func() { if _, ok := future.(sessiontxn.ConstantFuture); !ok { panic("tso shouldn't be requested") } }) failpoint.InjectContext(ctx, "mockGetTSFail", func() { future = txnFailFuture{} }) s.txn.changeToPending(&txnFuture{ future: future, store: s.store, txnScope: scope, }) return nil } // GetPreparedTxnFuture returns the TxnFuture if it is valid or pending. // It returns nil otherwise. func (s *session) GetPreparedTxnFuture() sessionctx.TxnFuture { if !s.txn.validOrPending() { return nil } return &s.txn } // RefreshTxnCtx implements context.RefreshTxnCtx interface. func (s *session) RefreshTxnCtx(ctx context.Context) error { var commitDetail *tikvutil.CommitDetails ctx = context.WithValue(ctx, tikvutil.CommitDetailCtxKey, &commitDetail) err := s.doCommit(ctx) if commitDetail != nil { s.GetSessionVars().StmtCtx.MergeExecDetails(nil, commitDetail) } if err != nil { return err } s.updateStatsDeltaToCollector() return sessiontxn.NewTxn(ctx, s) } // GetStore gets the store of session. func (s *session) GetStore() kv.Storage { return s.store } func (s *session) ShowProcess() *util.ProcessInfo { var pi *util.ProcessInfo tmp := s.processInfo.Load() if tmp != nil { pi = tmp.(*util.ProcessInfo) } return pi } // GetStartTSFromSession returns the startTS in the session `se` func GetStartTSFromSession(se interface{}) (uint64, uint64) { var startTS, processInfoID uint64 tmp, ok := se.(*session) if !ok { logutil.BgLogger().Error("GetStartTSFromSession failed, can't transform to session struct") return 0, 0 } processInfo := tmp.ShowProcess() if processInfo != nil { processInfoID = processInfo.ID } txnInfo := tmp.TxnInfo() if txnInfo != nil { startTS = txnInfo.StartTS } logutil.BgLogger().Debug( "GetStartTSFromSession getting startTS of internal session", zap.Uint64("startTS", startTS), zap.Time("start time", oracle.GetTimeFromTS(startTS))) return startTS, processInfoID } // logStmt logs some crucial SQL including: CREATE USER/GRANT PRIVILEGE/CHANGE PASSWORD/DDL etc and normal SQL // if variable.ProcessGeneralLog is set. func logStmt(execStmt *executor.ExecStmt, s *session) { vars := s.GetSessionVars() switch stmt := execStmt.StmtNode.(type) { case *ast.CreateUserStmt, *ast.DropUserStmt, *ast.AlterUserStmt, *ast.SetPwdStmt, *ast.GrantStmt, *ast.RevokeStmt, *ast.AlterTableStmt, *ast.CreateDatabaseStmt, *ast.CreateIndexStmt, *ast.CreateTableStmt, *ast.DropDatabaseStmt, *ast.DropIndexStmt, *ast.DropTableStmt, *ast.RenameTableStmt, *ast.TruncateTableStmt, *ast.RenameUserStmt: user := vars.User schemaVersion := s.GetInfoSchema().SchemaMetaVersion() if ss, ok := execStmt.StmtNode.(ast.SensitiveStmtNode); ok { logutil.BgLogger().Info("CRUCIAL OPERATION", zap.Uint64("conn", vars.ConnectionID), zap.Int64("schemaVersion", schemaVersion), zap.String("secure text", ss.SecureText()), zap.Stringer("user", user)) } else { logutil.BgLogger().Info("CRUCIAL OPERATION", zap.Uint64("conn", vars.ConnectionID), zap.Int64("schemaVersion", schemaVersion), zap.String("cur_db", vars.CurrentDB), zap.String("sql", stmt.Text()), zap.Stringer("user", user)) } default: logGeneralQuery(execStmt, s, false) } } func logGeneralQuery(execStmt *executor.ExecStmt, s *session, isPrepared bool) { vars := s.GetSessionVars() if variable.ProcessGeneralLog.Load() && !vars.InRestrictedSQL { var query string if isPrepared { query = execStmt.OriginText() } else { query = execStmt.GetTextToLog() } query = executor.QueryReplacer.Replace(query) if !vars.EnableRedactLog { query += vars.PreparedParams.String() } logutil.BgLogger().Info("GENERAL_LOG", zap.Uint64("conn", vars.ConnectionID), zap.String("user", vars.User.LoginString()), zap.Int64("schemaVersion", s.GetInfoSchema().SchemaMetaVersion()), zap.Uint64("txnStartTS", vars.TxnCtx.StartTS), zap.Uint64("forUpdateTS", vars.TxnCtx.GetForUpdateTS()), zap.Bool("isReadConsistency", vars.IsIsolation(ast.ReadCommitted)), zap.String("currentDB", vars.CurrentDB), zap.Bool("isPessimistic", vars.TxnCtx.IsPessimistic), zap.String("sessionTxnMode", vars.GetReadableTxnMode()), zap.String("sql", query)) } } func (s *session) recordOnTransactionExecution(err error, counter int, duration float64) { if s.sessionVars.TxnCtx.IsPessimistic { if err != nil { statementPerTransactionPessimisticError.Observe(float64(counter)) transactionDurationPessimisticAbort.Observe(duration) } else { statementPerTransactionPessimisticOK.Observe(float64(counter)) transactionDurationPessimisticCommit.Observe(duration) } } else { if err != nil { statementPerTransactionOptimisticError.Observe(float64(counter)) transactionDurationOptimisticAbort.Observe(duration) } else { statementPerTransactionOptimisticOK.Observe(float64(counter)) transactionDurationOptimisticCommit.Observe(duration) } } } func (s *session) checkPlacementPolicyBeforeCommit() error { var err error // Get the txnScope of the transaction we're going to commit. txnScope := s.GetSessionVars().TxnCtx.TxnScope if txnScope == "" { txnScope = kv.GlobalTxnScope } if txnScope != kv.GlobalTxnScope { is := s.GetInfoSchema().(infoschema.InfoSchema) deltaMap := s.GetSessionVars().TxnCtx.TableDeltaMap for physicalTableID := range deltaMap { var tableName string var partitionName string tblInfo, _, partInfo := is.FindTableByPartitionID(physicalTableID) if tblInfo != nil && partInfo != nil { tableName = tblInfo.Meta().Name.String() partitionName = partInfo.Name.String() } else { tblInfo, _ := is.TableByID(physicalTableID) tableName = tblInfo.Meta().Name.String() } bundle, ok := is.PlacementBundleByPhysicalTableID(physicalTableID) if !ok { errMsg := fmt.Sprintf("table %v doesn't have placement policies with txn_scope %v", tableName, txnScope) if len(partitionName) > 0 { errMsg = fmt.Sprintf("table %v's partition %v doesn't have placement policies with txn_scope %v", tableName, partitionName, txnScope) } err = dbterror.ErrInvalidPlacementPolicyCheck.GenWithStackByArgs(errMsg) break } dcLocation, ok := bundle.GetLeaderDC(placement.DCLabelKey) if !ok { errMsg := fmt.Sprintf("table %v's leader placement policy is not defined", tableName) if len(partitionName) > 0 { errMsg = fmt.Sprintf("table %v's partition %v's leader placement policy is not defined", tableName, partitionName) } err = dbterror.ErrInvalidPlacementPolicyCheck.GenWithStackByArgs(errMsg) break } if dcLocation != txnScope { errMsg := fmt.Sprintf("table %v's leader location %v is out of txn_scope %v", tableName, dcLocation, txnScope) if len(partitionName) > 0 { errMsg = fmt.Sprintf("table %v's partition %v's leader location %v is out of txn_scope %v", tableName, partitionName, dcLocation, txnScope) } err = dbterror.ErrInvalidPlacementPolicyCheck.GenWithStackByArgs(errMsg) break } // FIXME: currently we assume the physicalTableID is the partition ID. In future, we should consider the situation // if the physicalTableID belongs to a Table. partitionID := physicalTableID tbl, _, partitionDefInfo := is.FindTableByPartitionID(partitionID) if tbl != nil { tblInfo := tbl.Meta() state := tblInfo.Partition.GetStateByID(partitionID) if state == model.StateGlobalTxnOnly { err = dbterror.ErrInvalidPlacementPolicyCheck.GenWithStackByArgs( fmt.Sprintf("partition %s of table %s can not be written by local transactions when its placement policy is being altered", tblInfo.Name, partitionDefInfo.Name)) break } } } } return err } func (s *session) SetPort(port string) { s.sessionVars.Port = port } // GetTxnWriteThroughputSLI implements the Context interface. func (s *session) GetTxnWriteThroughputSLI() *sli.TxnWriteThroughputSLI { return &s.txn.writeSLI } // GetInfoSchema returns snapshotInfoSchema if snapshot schema is set. // Transaction infoschema is returned if inside an explicit txn. // Otherwise the latest infoschema is returned. func (s *session) GetInfoSchema() sessionctx.InfoschemaMetaVersion { vars := s.GetSessionVars() var is infoschema.InfoSchema if snap, ok := vars.SnapshotInfoschema.(infoschema.InfoSchema); ok { logutil.BgLogger().Info("use snapshot schema", zap.Uint64("conn", vars.ConnectionID), zap.Int64("schemaVersion", snap.SchemaMetaVersion())) is = snap } else if vars.TxnCtx != nil && vars.InTxn() { if tmp, ok := vars.TxnCtx.InfoSchema.(infoschema.InfoSchema); ok { is = tmp } } if is == nil { is = domain.GetDomain(s).InfoSchema() } // Override the infoschema if the session has temporary table. return temptable.AttachLocalTemporaryTableInfoSchema(s, is) } func (s *session) GetDomainInfoSchema() sessionctx.InfoschemaMetaVersion { is := domain.GetDomain(s).InfoSchema() extIs := &infoschema.SessionExtendedInfoSchema{InfoSchema: is} return temptable.AttachLocalTemporaryTableInfoSchema(s, extIs) } func getSnapshotInfoSchema(s sessionctx.Context, snapshotTS uint64) (infoschema.InfoSchema, error) { is, err := domain.GetDomain(s).GetSnapshotInfoSchema(snapshotTS) if err != nil { return nil, err } // Set snapshot does not affect the witness of the local temporary table. // The session always see the latest temporary tables. return temptable.AttachLocalTemporaryTableInfoSchema(s, is), nil } func (s *session) updateTelemetryMetric(es *executor.ExecStmt) { if es.Ti == nil { return } if s.isInternal() { return } ti := es.Ti if ti.UseRecursive { telemetryCTEUsageRecurCTE.Inc() } else if ti.UseNonRecursive { telemetryCTEUsageNonRecurCTE.Inc() } else { telemetryCTEUsageNotCTE.Inc() } if ti.UseIndexMerge { telemetryIndexMerge.Inc() } if ti.UseMultiSchemaChange { telemetryMultiSchemaChangeUsage.Inc() } if ti.UseFlashbackToCluster { telemetryFlashbackClusterUsage.Inc() } if ti.UesExchangePartition { telemetryExchangePartitionUsage.Inc() } if ti.PartitionTelemetry != nil { if ti.PartitionTelemetry.UseTablePartition { telemetryTablePartitionUsage.Inc() telemetryTablePartitionMaxPartitionsUsage.Add(float64(ti.PartitionTelemetry.TablePartitionMaxPartitionsNum)) } if ti.PartitionTelemetry.UseTablePartitionList { telemetryTablePartitionListUsage.Inc() } if ti.PartitionTelemetry.UseTablePartitionRange { telemetryTablePartitionRangeUsage.Inc() } if ti.PartitionTelemetry.UseTablePartitionHash { telemetryTablePartitionHashUsage.Inc() } if ti.PartitionTelemetry.UseTablePartitionRangeColumns { telemetryTablePartitionRangeColumnsUsage.Inc() } if ti.PartitionTelemetry.UseTablePartitionRangeColumnsGt1 { telemetryTablePartitionRangeColumnsGt1Usage.Inc() } if ti.PartitionTelemetry.UseTablePartitionRangeColumnsGt2 { telemetryTablePartitionRangeColumnsGt2Usage.Inc() } if ti.PartitionTelemetry.UseTablePartitionRangeColumnsGt3 { telemetryTablePartitionRangeColumnsGt3Usage.Inc() } if ti.PartitionTelemetry.UseTablePartitionListColumns { telemetryTablePartitionListColumnsUsage.Inc() } if ti.PartitionTelemetry.UseCreateIntervalPartition { telemetryTablePartitionCreateIntervalUsage.Inc() } if ti.PartitionTelemetry.UseAddIntervalPartition { telemetryTablePartitionAddIntervalUsage.Inc() } if ti.PartitionTelemetry.UseDropIntervalPartition { telemetryTablePartitionDropIntervalUsage.Inc() } if ti.PartitionTelemetry.UseCompactTablePartition { telemetryTableCompactPartitionUsage.Inc() } } if ti.AccountLockTelemetry != nil { telemetryLockUserUsage.Add(float64(ti.AccountLockTelemetry.LockUser)) telemetryUnlockUserUsage.Add(float64(ti.AccountLockTelemetry.UnlockUser)) telemetryCreateOrAlterUserUsage.Add(float64(ti.AccountLockTelemetry.CreateOrAlterUser)) } } // GetBuiltinFunctionUsage returns the replica of counting of builtin function usage func (s *session) GetBuiltinFunctionUsage() map[string]uint32 { replica := make(map[string]uint32) s.functionUsageMu.RLock() defer s.functionUsageMu.RUnlock() for key, value := range s.functionUsageMu.builtinFunctionUsage { replica[key] = value } return replica } // BuiltinFunctionUsageInc increase the counting of the builtin function usage func (s *session) BuiltinFunctionUsageInc(scalarFuncSigName string) { s.functionUsageMu.Lock() defer s.functionUsageMu.Unlock() s.functionUsageMu.builtinFunctionUsage.Inc(scalarFuncSigName) } func (s *session) GetStmtStats() *stmtstats.StatementStats { return s.stmtStats } // SetMemoryFootprintChangeHook sets the hook that is called when the memdb changes its size. // Call this after s.txn becomes valid, since TxnInfo is initialized when the txn becomes valid. func (s *session) SetMemoryFootprintChangeHook() { if config.GetGlobalConfig().Performance.TxnTotalSizeLimit != config.DefTxnTotalSizeLimit { // if the user manually specifies the config, don't involve the new memory tracker mechanism, let the old config // work as before. return } hook := func(mem uint64) { if s.sessionVars.MemDBFootprint == nil { tracker := memory.NewTracker(memory.LabelForMemDB, -1) tracker.AttachTo(s.sessionVars.MemTracker) s.sessionVars.MemDBFootprint = tracker } s.sessionVars.MemDBFootprint.ReplaceBytesUsed(int64(mem)) } s.txn.SetMemoryFootprintChangeHook(hook) } // EncodeSessionStates implements SessionStatesHandler.EncodeSessionStates interface. func (s *session) EncodeSessionStates(ctx context.Context, sctx sessionctx.Context, sessionStates *sessionstates.SessionStates) error { // Transaction status is hard to encode, so we do not support it. s.txn.mu.Lock() valid := s.txn.Valid() s.txn.mu.Unlock() if valid { return sessionstates.ErrCannotMigrateSession.GenWithStackByArgs("session has an active transaction") } // Data in local temporary tables is hard to encode, so we do not support it. // Check temporary tables here to avoid circle dependency. if s.sessionVars.LocalTemporaryTables != nil { localTempTables := s.sessionVars.LocalTemporaryTables.(*infoschema.SessionTables) if localTempTables.Count() > 0 { return sessionstates.ErrCannotMigrateSession.GenWithStackByArgs("session has local temporary tables") } } // The advisory locks will be released when the session is closed. if len(s.advisoryLocks) > 0 { return sessionstates.ErrCannotMigrateSession.GenWithStackByArgs("session has advisory locks") } // The TableInfo stores session ID and server ID, so the session cannot be migrated. if len(s.lockedTables) > 0 { return sessionstates.ErrCannotMigrateSession.GenWithStackByArgs("session has locked tables") } // It's insecure to migrate sandBoxMode because users can fake it. if s.InSandBoxMode() { return sessionstates.ErrCannotMigrateSession.GenWithStackByArgs("session is in sandbox mode") } if err := s.sessionVars.EncodeSessionStates(ctx, sessionStates); err != nil { return err } // Encode session variables. We put it here instead of SessionVars to avoid cycle import. sessionStates.SystemVars = make(map[string]string) for _, sv := range variable.GetSysVars() { switch { case sv.Hidden, sv.HasNoneScope(), sv.HasInstanceScope(), !sv.HasSessionScope(): // Hidden and none-scoped variables cannot be modified. // Instance-scoped variables don't need to be encoded. // Noop variables should also be migrated even if they are noop. continue case sv.ReadOnly: // Skip read-only variables here. We encode them into SessionStates manually. continue case sem.IsEnabled() && sem.IsInvisibleSysVar(sv.Name): // If they are shown, there will be a security issue. continue } // Get all session variables because the default values may change between versions. if val, keep, err := s.sessionVars.GetSessionStatesSystemVar(sv.Name); err != nil { return err } else if keep { sessionStates.SystemVars[sv.Name] = val } } // Encode prepared statements and sql bindings. for _, handler := range s.sessionStatesHandlers { if err := handler.EncodeSessionStates(ctx, s, sessionStates); err != nil { return err } } return nil } // DecodeSessionStates implements SessionStatesHandler.DecodeSessionStates interface. func (s *session) DecodeSessionStates(ctx context.Context, sctx sessionctx.Context, sessionStates *sessionstates.SessionStates) error { // Decode prepared statements and sql bindings. for _, handler := range s.sessionStatesHandlers { if err := handler.DecodeSessionStates(ctx, s, sessionStates); err != nil { return err } } // Decode session variables. for name, val := range sessionStates.SystemVars { if err := s.sessionVars.SetSystemVarWithoutValidation(name, val); err != nil { return err } } // Decoding session vars / prepared statements may override stmt ctx, such as warnings, // so we decode stmt ctx at last. return s.sessionVars.DecodeSessionStates(ctx, sessionStates) } func (s *session) setRequestSource(ctx context.Context, stmtLabel string, stmtNode ast.StmtNode) { if !s.isInternal() { if txn, _ := s.Txn(false); txn != nil && txn.Valid() { txn.SetOption(kv.RequestSourceType, stmtLabel) } else { s.sessionVars.RequestSourceType = stmtLabel } return } if source := ctx.Value(kv.RequestSourceKey); source != nil { requestSource := source.(kv.RequestSource) if requestSource.RequestSourceType != "" { s.sessionVars.RequestSourceType = requestSource.RequestSourceType return } } // panic in test mode in case there are requests without source in the future. // log warnings in production mode. if flag.Lookup("test.v") != nil || flag.Lookup("check.v") != nil { panic("unexpected no source type context, if you see this error, " + "the `RequestSourceTypeKey` is missing in your context") } else { logutil.Logger(ctx).Warn("unexpected no source type context, if you see this warning, "+ "the `RequestSourceTypeKey` is missing in the context", zap.Bool("internal", s.isInternal()), zap.String("sql", stmtNode.Text())) } } // RemoveLockDDLJobs removes the DDL jobs which doesn't get the metadata lock from job2ver. func RemoveLockDDLJobs(s Session, job2ver map[int64]int64, job2ids map[int64]string) { sv := s.GetSessionVars() if sv.InRestrictedSQL { return } sv.TxnCtxMu.Lock() defer sv.TxnCtxMu.Unlock() if sv.TxnCtx == nil { return } sv.GetRelatedTableForMDL().Range(func(tblID, value any) bool { for jobID, ver := range job2ver { ids := util.Str2Int64Map(job2ids[jobID]) if _, ok := ids[tblID.(int64)]; ok && value.(int64) < ver { delete(job2ver, jobID) logutil.BgLogger().Debug("old running transaction block DDL", zap.Int64("table ID", tblID.(int64)), zap.Uint64("conn ID", sv.ConnectionID)) } } return true }) }