Files
tidb/br/pkg/utils/db.go
2023-01-22 11:09:50 +08:00

232 lines
6.8 KiB
Go

// Copyright 2021 PingCAP, Inc. Licensed under Apache-2.0.
package utils
import (
"context"
"database/sql"
"strconv"
"strings"
"sync"
"github.com/docker/go-units"
"github.com/pingcap/errors"
"github.com/pingcap/log"
"github.com/pingcap/tidb/br/pkg/logutil"
"github.com/pingcap/tidb/kv"
"github.com/pingcap/tidb/sessionctx"
"github.com/pingcap/tidb/util/sqlexec"
"go.uber.org/zap"
)
const (
tidbNewCollationEnabled = "new_collation_enabled"
)
var (
// check sql.DB and sql.Conn implement QueryExecutor and DBExecutor
_ DBExecutor = &sql.DB{}
_ DBExecutor = &sql.Conn{}
LogBackupTaskMutex sync.Mutex
logBackupTaskCount int
)
// QueryExecutor is a interface for exec query
type QueryExecutor interface {
QueryContext(ctx context.Context, query string, args ...interface{}) (*sql.Rows, error)
QueryRowContext(ctx context.Context, query string, args ...interface{}) *sql.Row
}
// StmtExecutor define both query and exec methods
type StmtExecutor interface {
QueryExecutor
ExecContext(ctx context.Context, query string, args ...interface{}) (sql.Result, error)
}
// DBExecutor is a interface for statements and txn
type DBExecutor interface {
StmtExecutor
BeginTx(ctx context.Context, opts *sql.TxOptions) (*sql.Tx, error)
}
// CheckLogBackupEnabled checks if LogBackup is enabled in cluster.
// this mainly used in three places.
// 1. GC worker resolve locks to scan more locks after safepoint. (every minute)
// 2. Add index skipping use lightning.(every add index ddl)
// 3. Telemetry of log backup feature usage (every 6 hours).
// NOTE: this result shouldn't be cached by caller. because it may change every time in one cluster.
func CheckLogBackupEnabled(ctx sessionctx.Context) bool {
executor, ok := ctx.(sqlexec.RestrictedSQLExecutor)
if !ok {
// shouldn't happen
log.Error("[backup] unable to translate executor from sessionctx")
return false
}
enabled, err := IsLogBackupEnabled(executor)
if err != nil {
// if it failed by any reason. we can simply return true this time.
// for GC worker it will scan more locks in one tick.
// for Add index it will skip using lightning this time.
// for Telemetry it will get a false positive usage count.
log.Warn("[backup] check log backup config failed, ignore it", zap.Error(err))
return true
}
return enabled
}
// IsLogBackupEnabled is used for br to check whether tikv has enabled log backup.
// we use `sqlexec.RestrictedSQLExecutor` as parameter because it's easy to mock.
// it should return error.
func IsLogBackupEnabled(ctx sqlexec.RestrictedSQLExecutor) (bool, error) {
valStr := "show config where name = 'log-backup.enable' and type = 'tikv'"
internalCtx := kv.WithInternalSourceType(context.Background(), kv.InternalTxnBR)
rows, fields, errSQL := ctx.ExecRestrictedSQL(internalCtx, nil, valStr)
if errSQL != nil {
return false, errSQL
}
if len(rows) == 0 {
// no rows mean not support log backup.
return false, nil
}
for _, row := range rows {
d := row.GetDatum(3, &fields[3].Column.FieldType)
value, errField := d.ToString()
if errField != nil {
return false, errField
}
if strings.ToLower(value) == "false" {
return false, nil
}
}
return true, nil
}
func GetRegionSplitInfo(ctx sqlexec.RestrictedSQLExecutor) (uint64, int64) {
return GetSplitSize(ctx), GetSplitKeys(ctx)
}
func GetSplitSize(ctx sqlexec.RestrictedSQLExecutor) uint64 {
const defaultSplitSize = 96 * 1024 * 1024
varStr := "show config where name = 'coprocessor.region-split-size' and type = 'tikv'"
rows, fields, err := ctx.ExecRestrictedSQL(
kv.WithInternalSourceType(context.Background(), kv.InternalTxnBR),
nil,
varStr,
)
if err != nil {
log.Warn("failed to get split size, use default value", logutil.ShortError(err))
return defaultSplitSize
}
if len(rows) == 0 {
// use the default value
return defaultSplitSize
}
d := rows[0].GetDatum(3, &fields[3].Column.FieldType)
splitSizeStr, err := d.ToString()
if err != nil {
log.Warn("failed to get split size, use default value", logutil.ShortError(err))
return defaultSplitSize
}
splitSize, err := units.FromHumanSize(splitSizeStr)
if err != nil {
log.Warn("failed to get split size, use default value", logutil.ShortError(err))
return defaultSplitSize
}
return uint64(splitSize)
}
func GetSplitKeys(ctx sqlexec.RestrictedSQLExecutor) int64 {
const defaultSplitKeys = 960000
varStr := "show config where name = 'coprocessor.region-split-keys' and type = 'tikv'"
rows, fields, err := ctx.ExecRestrictedSQL(
kv.WithInternalSourceType(context.Background(), kv.InternalTxnBR),
nil,
varStr,
)
if err != nil {
log.Warn("failed to get split keys, use default value", logutil.ShortError(err))
return defaultSplitKeys
}
if len(rows) == 0 {
// use the default value
return defaultSplitKeys
}
d := rows[0].GetDatum(3, &fields[3].Column.FieldType)
splitKeysStr, err := d.ToString()
if err != nil {
log.Warn("failed to get split keys, use default value", logutil.ShortError(err))
return defaultSplitKeys
}
splitKeys, err := strconv.ParseInt(splitKeysStr, 10, 64)
if err != nil {
log.Warn("failed to get split keys, use default value", logutil.ShortError(err))
return defaultSplitKeys
}
return splitKeys
}
func GetGcRatio(ctx sqlexec.RestrictedSQLExecutor) (string, error) {
valStr := "show config where name = 'gc.ratio-threshold' and type = 'tikv'"
rows, fields, errSQL := ctx.ExecRestrictedSQL(
kv.WithInternalSourceType(context.Background(), kv.InternalTxnBR),
nil,
valStr,
)
if errSQL != nil {
return "", errSQL
}
if len(rows) == 0 {
// no rows mean not support log backup.
return "", nil
}
d := rows[0].GetDatum(3, &fields[3].Column.FieldType)
return d.ToString()
}
func SetGcRatio(ctx sqlexec.RestrictedSQLExecutor, ratio string) error {
_, _, err := ctx.ExecRestrictedSQL(
kv.WithInternalSourceType(context.Background(), kv.InternalTxnBR),
nil,
"set config tikv `gc.ratio-threshold`=%?",
ratio,
)
if err != nil {
return errors.Annotatef(err, "failed to set config `gc.ratio-threshold`=%s", ratio)
}
log.Warn("set config tikv gc.ratio-threshold", zap.String("ratio", ratio))
return nil
}
// LogBackupTaskCountInc increases the count of log backup task.
func LogBackupTaskCountInc() {
LogBackupTaskMutex.Lock()
logBackupTaskCount++
LogBackupTaskMutex.Unlock()
}
// LogBackupTaskCountDec decreases the count of log backup task.
func LogBackupTaskCountDec() {
LogBackupTaskMutex.Lock()
logBackupTaskCount--
LogBackupTaskMutex.Unlock()
}
// CheckLogBackupTaskExist checks that whether log-backup is existed.
func CheckLogBackupTaskExist() bool {
return logBackupTaskCount > 0
}
// IsLogBackupInUse checks the log backup task existed.
func IsLogBackupInUse(ctx sessionctx.Context) bool {
return CheckLogBackupEnabled(ctx) && CheckLogBackupTaskExist()
}
// GetTidbNewCollationEnabled returns the variable name of NewCollationEnabled.
func GetTidbNewCollationEnabled() string {
return tidbNewCollationEnabled
}