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Adjust the read snapshot when max_read_stale_time is valid

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This commit is contained in:
obdev
2023-06-05 08:56:46 +00:00
committed by ob-robot
parent a795853f8e
commit 843c5c9db3
4 changed files with 28 additions and 19 deletions
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2
src/observer/table/ob_table_rpc_processor.cpp
View File

@ -401,7 +401,7 @@ int ObTableApiProcessorBase::setup_tx_snapshot_(transaction::ObTxDesc &trans_des
} else {
SCN weak_read_snapshot;
if (OB_FAIL(txs->get_weak_read_snapshot_version(
transaction::ObWeakReadUtil::max_stale_time_for_weak_consistency(MTL_ID()),
-1, // system variable : max read stale time for user
weak_read_snapshot))) {
LOG_WARN("fail to get weak read snapshot", K(ret));
} else {

4
src/sql/ob_sql_trans_control.cpp
View File

@ -642,7 +642,7 @@ int ObSqlTransControl::stmt_setup_snapshot_(ObSQLSessionInfo *session,
if (cl == ObConsistencyLevel::WEAK || cl == ObConsistencyLevel::FROZEN) {
SCN snapshot_version = SCN::min_scn();
if (OB_FAIL(txs->get_weak_read_snapshot_version(session->get_ob_max_read_stale_time(),
snapshot_version))) {
snapshot_version))) {
TRANS_LOG(WARN, "get weak read snapshot fail", KPC(txs));
int64_t stale_time = session->get_ob_max_read_stale_time();
int64_t refresh_interval = GCONF.weak_read_version_refresh_interval;
@ -1188,7 +1188,7 @@ int ObSqlTransControl::check_ls_readable(const uint64_t tenant_id,
|| max_stale_time_us <= -2) {
ret = OB_INVALID_ARGUMENT;
LOG_WARN("invalid argument", K(ls_id), K(addr), K(max_stale_time_us));
} else if (-1 == max_stale_time_us) {
} else if (max_stale_time_us < 0) {
// no need check
can_read = true;
} else if (observer::ObServer::get_instance().get_self() == addr) {

2
src/storage/concurrency_control/ob_multi_version_garbage_collector.cpp
View File

@ -441,7 +441,7 @@ int ObMultiVersionGarbageCollector::study_min_unallocated_WRS(
transaction::ObWeakReadUtil::max_stale_time_for_weak_consistency(MTL_ID());
if (OB_FAIL(MTL(transaction::ObTransService*)->get_weak_read_snapshot_version(
max_read_stale_time,
-1, // system variable : max read stale time for user
min_unallocated_WRS))) {
MVCC_LOG(WARN, "fail to get weak read snapshot", K(ret));
if (OB_REPLICA_NOT_READABLE == ret) {

39
src/storage/tx/ob_tx_api.cpp
View File

@ -710,33 +710,42 @@ int ObTransService::get_ls_read_snapshot_version(const share::ObLSID &local_ls_i
return ret;
}
ERRSIM_POINT_DEF(ERRSIM_WEAK_READ_SNAPSHOT_DELAY_US);
int ObTransService::get_weak_read_snapshot_version(const int64_t max_read_stale_time,
int ObTransService::get_weak_read_snapshot_version(const int64_t max_read_stale_us_for_user,
SCN &snapshot)
{
int ret = OB_SUCCESS;
bool monotinic_read = true;;
SCN wrs_scn;
// server weak read version
if (!ObWeakReadUtil::enable_monotonic_weak_read(tenant_id_)) {
if (OB_FAIL(GCTX.weak_read_service_->get_server_version(tenant_id_, snapshot))) {
if (OB_FAIL(GCTX.weak_read_service_->get_server_version(tenant_id_, wrs_scn))) {
TRANS_LOG(WARN, "get server read snapshot fail", K(ret), KPC(this));
}
monotinic_read = false;
// wrs cluster version
} else if (OB_FAIL(GCTX.weak_read_service_->get_cluster_version(tenant_id_, snapshot))) {
} else if (OB_FAIL(GCTX.weak_read_service_->get_cluster_version(tenant_id_, wrs_scn))) {
TRANS_LOG(WARN, "get weak read snapshot fail", K(ret), KPC(this));
} else if (-1 == max_read_stale_time) {
// no need to check barrier version
// do nothing
} else {
// check snapshot version barrier which is setted by user system variable
const int64_t snapshot_barrier = ObTimeUtility::current_time() - max_read_stale_time
+ abs(ERRSIM_WEAK_READ_SNAPSHOT_DELAY_US);
if (snapshot.convert_to_ts() < snapshot_barrier) {
TRANS_LOG(WARN, "weak read snapshot too stale", K(snapshot),
K(snapshot_barrier), "delta", (snapshot_barrier - snapshot.convert_to_ts()));
ret = OB_REPLICA_NOT_READABLE;
// do nothing
}
if (OB_SUCC(ret)) {
if (max_read_stale_us_for_user < 0) {
// no need to check barrier version
snapshot = wrs_scn;
} else {
// check snapshot version barrier which is setted by user system variable
SCN gts_cache;
SCN current_scn;
if (OB_FAIL(OB_TS_MGR.get_gts(tenant_id_, NULL, gts_cache))) {
TRANS_LOG(WARN, "get ts sync error", K(ret), K(max_read_stale_us_for_user));
} else {
const int64_t current_time_us = MTL_IS_PRIMARY_TENANT()
? std::max(ObTimeUtility::current_time(), gts_cache.convert_to_ts())
: 0 ;
current_scn.convert_from_ts(current_time_us - max_read_stale_us_for_user);
snapshot = SCN::max(wrs_scn, current_scn);
}
}
}
TRANS_LOG(TRACE, "get weak-read snapshot", K(ret), K(snapshot), K(monotinic_read));