ddl: don't write binlog for 'ALTER TABLE t CACHE|NOCACHE' (#31106)

close pingcap/tidb#31105

ddl/ddl_worker.go

@@ -621,6 +621,10 @@ func skipWriteBinlog(job *model.Job) bool {
 	// it's used to update table's TiFlash replica available status.
 	case model.ActionUpdateTiFlashReplicaStatus:
 		return true
+	// Don't sync 'alter table cache|nocache' to other tools.
+	// It's internal to the current cluster.
+	case model.ActionAlterCacheTable, model.ActionAlterNoCacheTable:
+		return true
 	}
 
 	return false

sessionctx/binloginfo/binloginfo_test.go

@@ -675,6 +675,14 @@ func TestAddSpecialComment(t *testing.T) {
 			"alter table t force, auto_increment = 12;",
 			"alter table t force, auto_increment = 12;",
 		},
+		{
+			"alter table t cache",
+			"alter table t cache",
+		},
+		{
+			"alter table t nocache",
+			"alter table t nocache",
+		},
 	}
 	for _, ca := range testCase {
 		re := binloginfo.AddSpecialComment(ca.input)
@@ -785,6 +793,32 @@ func TestTempTableBinlog(t *testing.T) {
 	require.True(t, ok)
 }
 
+func TestAlterTableCache(t *testing.T) {
+	s, clean := createBinlogSuite(t)
+	defer clean()
+
+	// Don't write binlog for 'ALTER TABLE t CACHE|NOCACHE'.
+	// Cached table is regarded as normal table.
+
+	tk := testkit.NewTestKit(t, s.store)
+	tk.MustExec("use test")
+	tk.Session().GetSessionVars().BinlogClient = s.client
+	tk.MustExec("drop table if exists t")
+	ddlQuery := "create table t (id int)"
+	tk.MustExec(ddlQuery)
+
+	tk.MustExec(`alter table t cache`)
+	// The latest DDL is still the previous one.
+	getLatestDDLBinlog(t, s.pump, ddlQuery)
+
+	tk.MustExec("insert into t values (?)", 666)
+	prewriteVal := getLatestBinlogPrewriteValue(t, s.pump)
+	require.Equal(t, 1, len(prewriteVal.Mutations))
+
+	tk.MustExec(`alter table t nocache`)
+	getLatestDDLBinlog(t, s.pump, ddlQuery)
+}
+
 func TestIssue28292(t *testing.T) {
 	s, clean := createBinlogSuite(t)
 	defer clean()