session: fix unsecessfully set the isolation read engines (pingcap#17258

) (pingcap#17322)
lzmhhh123 · Oct 21, 2020 · 1930573 · 1930573
1 parent beae9ef
commit 1930573
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Showing 2 changed files with 29 additions and 2 deletions.
diff --git a/sessionctx/variable/session.go b/sessionctx/variable/session.go
@@ -676,7 +676,7 @@ func NewSessionVars() *SessionVars {
 		AllowRemoveAutoInc:          DefTiDBAllowRemoveAutoInc,
 		UsePlanBaselines:            DefTiDBUsePlanBaselines,
 		EvolvePlanBaselines:         DefTiDBEvolvePlanBaselines,
-		IsolationReadEngines:        map[kv.StoreType]struct{}{kv.TiKV: {}, kv.TiFlash: {}, kv.TiDB: {}},
+		IsolationReadEngines:        make(map[kv.StoreType]struct{}),
 		LockWaitTimeout:             DefInnodbLockWaitTimeout * 1000,
 		MetricSchemaStep:            DefTiDBMetricSchemaStep,
 		MetricSchemaRangeDuration:   DefTiDBMetricSchemaRangeDuration,
@@ -733,6 +733,16 @@ func NewSessionVars() *SessionVars {
 		enableChunkRPC = "0"
 	}
 	terror.Log(vars.SetSystemVar(TiDBEnableChunkRPC, enableChunkRPC))
+	for _, engine := range config.GetGlobalConfig().IsolationRead.Engines {
+		switch engine {
+		case kv.TiFlash.Name():
+			vars.IsolationReadEngines[kv.TiFlash] = struct{}{}
+		case kv.TiKV.Name():
+			vars.IsolationReadEngines[kv.TiKV] = struct{}{}
+		case kv.TiDB.Name():
+			vars.IsolationReadEngines[kv.TiDB] = struct{}{}
+		}
+	}
 	return vars
 }
 

diff --git a/sessionctx/variable/session_test.go b/sessionctx/variable/session_test.go
@@ -19,14 +19,16 @@ import (
 	. "github.com/pingcap/check"
 	"github.com/pingcap/parser"
 	"github.com/pingcap/parser/auth"
+	"github.com/pingcap/tidb/config"
+	"github.com/pingcap/tidb/kv"
 	"github.com/pingcap/tidb/sessionctx/stmtctx"
 	"github.com/pingcap/tidb/sessionctx/variable"
 	"github.com/pingcap/tidb/types"
 	"github.com/pingcap/tidb/util/execdetails"
 	"github.com/pingcap/tidb/util/mock"
 )
 
-var _ = Suite(&testSessionSuite{})
+var _ = SerialSuites(&testSessionSuite{})
 
 type testSessionSuite struct {
 }
@@ -214,3 +216,18 @@ select * from t;`
 	})
 	c.Assert(logString, Equals, resultString)
 }
+
+func (*testSessionSuite) TestIsolationRead(c *C) {
+	originIsolationEngines := config.GetGlobalConfig().IsolationRead.Engines
+	defer func() {
+		config.GetGlobalConfig().IsolationRead.Engines = originIsolationEngines
+	}()
+	config.GetGlobalConfig().IsolationRead.Engines = []string{"tiflash", "tidb"}
+	sessVars := variable.NewSessionVars()
+	_, ok := sessVars.IsolationReadEngines[kv.TiDB]
+	c.Assert(ok, Equals, true)
+	_, ok = sessVars.IsolationReadEngines[kv.TiKV]
+	c.Assert(ok, Equals, false)
+	_, ok = sessVars.IsolationReadEngines[kv.TiFlash]
+	c.Assert(ok, Equals, true)
+}