From 10e6c4ea60a3c59687687b327f5efb2906a6d2e7 Mon Sep 17 00:00:00 2001
From: Yiding Cui <winoros@gmail.com>
Date: Fri, 28 Oct 2022 15:36:51 +0800
Subject: [PATCH] cherry pick #37078

---
 executor/adapter.go              | 12 ++++++++++++
 sessionctx/variable/sysvar.go    |  2 ++
 sessionctx/variable/tidb_vars.go |  7 +++++++
 3 files changed, 21 insertions(+)

diff --git a/executor/adapter.go b/executor/adapter.go
index b8f616e773a72..30143421b4e0f 100644
--- a/executor/adapter.go
+++ b/executor/adapter.go
@@ -460,6 +460,18 @@ func (a *ExecStmt) Exec(ctx context.Context) (_ sqlexec.RecordSet, err error) {
 			oriStats = strconv.Itoa(variable.DefBuildStatsConcurrency)
 		}
 		oriScan := sctx.GetSessionVars().DistSQLScanConcurrency()
+		autoConcurrency, err1 := sctx.GetSessionVars().GetSessionOrGlobalSystemVar(variable.TiDBAutoBuildStatsConcurrency)
+		terror.Log(err1)
+		if err1 == nil {
+			terror.Log(sctx.GetSessionVars().SetSystemVar(variable.TiDBBuildStatsConcurrency, autoConcurrency))
+		}
+		sVal, err2 := sctx.GetSessionVars().GetSessionOrGlobalSystemVar(variable.TiDBSysProcScanConcurrency)
+		terror.Log(err2)
+		if err2 == nil {
+			concurrency, err3 := strconv.ParseInt(sVal, 10, 64)
+			terror.Log(err3)
+			sctx.GetSessionVars().SetDistSQLScanConcurrency(int(concurrency))
+		}
 		oriIndex := sctx.GetSessionVars().IndexSerialScanConcurrency()
 		oriIso, ok := sctx.GetSessionVars().GetSystemVar(variable.TxnIsolation)
 		if !ok {
diff --git a/sessionctx/variable/sysvar.go b/sessionctx/variable/sysvar.go
index 37fd015fce28f..0e9c2913f978e 100644
--- a/sessionctx/variable/sysvar.go
+++ b/sessionctx/variable/sysvar.go
@@ -672,6 +672,8 @@ var defaultSysVars = []*SysVar{
 		TableCacheLease.Store(val)
 		return nil
 	}},
+	{Scope: ScopeGlobal, Name: TiDBAutoBuildStatsConcurrency, Value: strconv.Itoa(DefTiDBAutoBuildStatsConcurrency), Type: TypeInt, MinValue: 1, MaxValue: MaxConfigurableConcurrency},
+	{Scope: ScopeGlobal, Name: TiDBSysProcScanConcurrency, Value: strconv.Itoa(DefTiDBSysProcScanConcurrency), Type: TypeInt, MinValue: 1, MaxValue: MaxConfigurableConcurrency},
 	// variable for top SQL feature.
 	// TopSQL enable only be controlled by TopSQL pub/sub sinker.
 	// This global variable only uses to update the global config which store in PD(ETCD).
diff --git a/sessionctx/variable/tidb_vars.go b/sessionctx/variable/tidb_vars.go
index 06da8d8c53ce8..b0f751d5e7397 100644
--- a/sessionctx/variable/tidb_vars.go
+++ b/sessionctx/variable/tidb_vars.go
@@ -765,6 +765,11 @@ const (
 	// ranges would exceed the limit, it chooses less accurate ranges such as full range. 0 indicates that there is no memory
 	// limit for ranges.
 	TiDBOptRangeMaxSize = "tidb_opt_range_max_size"
+
+	// TiDBAutoBuildStatsConcurrency is used to set the build concurrency of auto-analyze.
+	TiDBAutoBuildStatsConcurrency = "tidb_auto_build_stats_concurrency"
+	// TiDBSysProcScanConcurrency is used to set the scan concurrency of for backend system processes, like auto-analyze.
+	TiDBSysProcScanConcurrency = "tidb_sysproc_scan_concurrency"
 )
 
 // TiDB vars that have only global scope
@@ -1072,6 +1077,8 @@ const (
 	DefTiDBForeignKeyChecks                         = false
 	DefTiDBOptRangeMaxSize                          = 0
 	DefTiDBCostModelVer                             = 1
+	DefTiDBAutoBuildStatsConcurrency                = 1
+	DefTiDBSysProcScanConcurrency                   = 1
 )
 
 // Process global variables.