tidb session 源码
tidb session 代码
文件路径：/session/session.go
// 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/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/errno"
"github.com/pingcap/tidb/executor"
"github.com/pingcap/tidb/expression"
"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/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/sem"
"github.com/pingcap/tidb/util/sli"
"github.com/pingcap/tidb/util/sqlexec"
"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
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
telemetryLockUserUsage = metrics.TelemetryAccountLockCnt.WithLabelValues("lockUser")
telemetryUnlockUserUsage = metrics.TelemetryAccountLockCnt.WithLabelValues("unlockUser")
telemetryCreateOrAlterUserUsage = metrics.TelemetryAccountLockCnt.WithLabelValues("createOrAlterUser")
)
// 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)
// CacheGeneralStmt parses the sql, generates the corresponding PlanCacheStmt and cache it.
CacheGeneralStmt(sql string) (interface{}, 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 []byte, 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()
}
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
generalPlanCache 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 {
sync.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
}
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(isGeneralPlanCache bool) sessionctx.PlanCache {
if isGeneralPlanCache { // use the general plan cache
if !s.GetSessionVars().EnableGeneralPlanCache {
return nil
}
if s.generalPlanCache == nil { // lazy construction
s.generalPlanCache = plannercore.NewLRUPlanCache(uint(s.GetSessionVars().GeneralPlanCacheSize),
variable.PreparedPlanCacheMemoryGuardRatio.Load(), plannercore.PreparedPlanCacheMaxMemory.Load(),
plannercore.PickPlanFromBucket)
}
return s.generalPlanCache
}
// 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(),
plannercore.PickPlanFromBucket)
}
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 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
}
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 })
if sessVars.EnableAmendPessimisticTxn {
s.txn.SetOption(kv.SchemaAmender, NewSchemaAmenderForTikvTxn(s))
}
s.txn.SetOption(kv.EnableAsyncCommit, sessVars.EnableAsyncCommit)
s.txn.SetOption(kv.Enable1PC, sessVars.Enable1PC)
s.txn.SetOption(kv.ResourceGroupTagger, sessVars.StmtCtx.GetResourceGroupTagger())
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))
}
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 {
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 {
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
}
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()
break
}
s.StmtCommit()
}
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)
}
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)
}
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) 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()
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(name, 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(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)
}
// 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.
func (s *session) SetGlobalSysVarOnly(name, value string) (err error) {
sv := variable.GetSysVar(name)
if sv == nil {
return variable.ErrUnknownSystemVar.GenWithStackByArgs(name)
}
if err = sv.SetGlobalFromHook(s.sessionVars, value, true); err != nil {
return err
}
if sv.HasInstanceScope() { // skip for INSTANCE scope
return nil
}
return s.replaceGlobalVariablesTableValue(context.TODO(), sv.Name, value)
}
// 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,
StatsInfo: plannercore.GetStatsInfo,
MaxExecutionTime: maxExecutionTime,
RedactSQL: s.sessionVars.EnableRedactLog,
}
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) 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.GetStore())
if err != nil {
return err
}
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)
}
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)
}
return count
}
// 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
}, 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
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.ExecuteStmt(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
})
}
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
}
s.sessionVars.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 {
err = sessiontxn.OptimizeWithPlanAndThenWarmUp(s, stmt.Plan)
}
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 {
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 {
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)
}
}
// CacheGeneralStmt parses the sql, generates the corresponding PlanCacheStmt and cache it.
// The sql have to be parameterized, e.g. select * from t where a>?.
func (s *session) CacheGeneralStmt(sql string) (interface{}, error) {
if stmt := s.sessionVars.GetGeneralPlanCacheStmt(sql); stmt != nil {
// skip this step if there is already a PlanCacheStmt for this ql
return stmt, nil
}
prepareExec := executor.NewPrepareExec(s, sql)
prepareExec.IsGeneralStmt = true
if err := prepareExec.Next(context.Background(), nil); err != nil {
return nil, err
}
return prepareExec.Stmt, nil
}
// 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()
inTxn := s.GetSessionVars().InTxn()
// 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)
if err != nil {
return
}
if !inTxn {
// We could start a transaction to build the prepare executor before, we should rollback it here.
s.RollbackTxn(ctx)
}
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()
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()
}
// 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.GetAuthPlugin(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 []byte, 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)
}
if err = pm.ConnectionVerification(user, authUser.Username, authUser.Hostname, authentication, salt, s.sessionVars.TLSConnectionState); err != nil {
return err
}
user.AuthUsername = authUser.Username
user.AuthHostname = authUser.Hostname
s.sessionVars.User = user
s.sessionVars.ActiveRoles = pm.GetDefaultRoles(user.AuthUsername, user.AuthHostname)
return 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
}
pm := &privileges.UserPrivileges{
Handle: do.PrivilegeHandle(),
}
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
}
var (
errResultIsEmpty = dbterror.ClassExecutor.NewStd(errno.ErrResultIsEmpty)
// DDLJobTables is a list of tables definitions used in concurrent DDL.
DDLJobTables = []struct {
SQL string
id int64
}{
{ddl.JobTableSQL, ddl.JobTableID},
{ddl.ReorgTableSQL, ddl.ReorgTableID},
{ddl.HistoryTableSQL, ddl.HistoryTableID},
}
mdlTable = "create table mysql.tidb_mdl_info(job_id BIGINT NOT NULL PRIMARY KEY, version BIGINT NOT NULL, table_ids text(65535));"
)
// InitDDLJobTables is to create tidb_ddl_job, tidb_ddl_reorg and tidb_ddl_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 || exists {
return errors.Trace(err)
}
dbID, err := t.CreateMySQLDatabaseIfNotExists()
if err != nil {
return err
}
p := parser.New()
for _, tbl := range DDLJobTables {
id, err := t.GetGlobalID()
if err != nil {
return errors.Trace(err)
}
if id >= meta.MaxGlobalID {
return errors.Errorf("It is unreasonable that the global ID grows such a big value: %d, please contact TiDB team", id)
}
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 t.SetDDLTables()
})
}
// 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
}
p := parser.New()
id, err := t.GetGlobalID()
if err != nil {
return errors.Trace(err)
}
if id >= meta.MaxGlobalID {
return errors.Errorf("It is unreasonable that the global ID grows such a big value: %d, please contact TiDB team", id)
}
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()
})
}
// 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)
}
concurrency := int(config.GetGlobalConfig().Performance.StatsLoadConcurrency)
ses, err := createSessions(store, 7+concurrency)
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 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.
go func() {
dom.TelemetryReportLoop(ses[5])
dom.TelemetryRotateSubWindowLoop(ses[5])
}()
}
// A sub context for update table stats, and other contexts for concurrent stats loading.
cnt := 1 + concurrency
subCtxs := make([]sessionctx.Context, cnt)
for i := 0; i < cnt; i++ {
subCtxs[i] = sessionctx.Context(ses[6+i])
}
if err = dom.LoadAndUpdateStatsLoop(subCtxs); err != nil {
return nil, err
}
dom.DumpFileGcCheckerLoop()
dom.LoadSigningCertLoop()
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
}
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,
sessionVars: variable.NewSessionVars(),
ddlOwnerManager: dom.DDL().OwnerManager(),
client: store.GetClient(),
mppClient: store.GetMPPClient(),
stmtStats: stmtstats.CreateStatementStats(),
sessionStatesHandlers: make(map[sessionstates.SessionStateType]sessionctx.SessionStatesHandler),
}
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(parser.New())
s.SetValue(bindinfo.SessionBindInfoKeyType, sessionBindHandle)
s.SetSessionStatesHandler(sessionstates.StateBinding, sessionBindHandle)
return s, nil
}
// 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(),
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() || s.sessionVars.RetryInfo.Retrying ||
config.GetGlobalConfig().PessimisticTxn.PessimisticAutoCommit.Load() {
if s.sessionVars.TxnMode == ast.Pessimistic {
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()
return temptable.AttachLocalTemporaryTableInfoSchema(s, is)
}
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.UseMultiSchemaChange {
telemetryMultiSchemaChangeUsage.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.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
}
// 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")
}
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
}
} else {
if source := ctx.Value(kv.RequestSourceKey); source != nil {
s.sessionVars.RequestSourceType = source.(kv.RequestSource).RequestSourceType
} else {
// 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) {
if s.GetSessionVars().InRestrictedSQL {
return
}
s.GetSessionVars().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", s.GetSessionVars().ConnectionID))
}
}
return true
})
}
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