ddl: make test TestRenameTableAutoIDs more stable (#54695)

close #53765

Author: tiancaiamao

pkg/ddl/schema_test.go

@@ -372,7 +372,7 @@ func testCheckJobCancelled(t *testing.T, store kv.Storage, job *model.Job, state
 }
 
 func TestRenameTableAutoIDs(t *testing.T) {
-	store := testkit.CreateMockStore(t)
+	store, dom := testkit.CreateMockStoreAndDomain(t)
 	tk1 := testkit.NewTestKit(t, store)
 	tk2 := testkit.NewTestKit(t, store)
 	tk3 := testkit.NewTestKit(t, store)
@@ -396,6 +396,7 @@ func TestRenameTableAutoIDs(t *testing.T) {
 			if len(res) == 1 && res[0][col] == s {
 				break
 			}
+
 			logutil.DDLLogger().Info("Could not find match", zap.String("tableName", tableName), zap.String("s", s), zap.Int("colNum", col))
 
 			for i := range res {
@@ -412,19 +413,32 @@ func TestRenameTableAutoIDs(t *testing.T) {
 	tk2.MustExec(`set @@session.innodb_lock_wait_timeout = 0`)
 	tk2.MustExec(`BEGIN`)
 	tk2.MustExec(`insert into t values (null, 4)`)
+
+	v1 := dom.InfoSchema().SchemaMetaVersion()
+
 	go func() {
 		alterChan <- tk1.ExecToErr(`rename table t to ` + dbName + `2.t2`)
 	}()
 	waitFor(11, "t", "running")
 	waitFor(4, "t", "public")
+
+	// ddl finish does not mean the infoschema loaded.
+	// when infoschema v1->v2 switch, it take more time, so we must wait to ensure
+	// the new infoschema is used.
+	require.Eventually(t, func() bool { return dom.InfoSchema().SchemaMetaVersion() > v1 }, time.Minute, 2*time.Millisecond)
+
 	tk3.MustExec(`BEGIN`)
 	tk3.MustExec(`insert into ` + dbName + `2.t2 values (50, 5)`)
-
+	// TODO: still unstable here.
+	// This is caused by a known rename table and autoid compatibility issue.
+	// In the past we try to fix it by the same auto id allocator before and after table renames.
+	//     https://github.com/pingcap/tidb/pull/47892
+	// But during infoschema v1->v2 switch, infoschema full load happen, then both the old and new
+	// autoid instance exists. tk2 here use the old autoid allocator, cause txn conflict on index key
+	// b=20, conflicting with the next line insert values (20, 5)
 	tk2.MustExec(`insert into t values (null, 6)`)
 	tk3.MustExec(`insert into ` + dbName + `2.t2 values (20, 5)`)
-
 	// Done: Fix https://github.com/pingcap/tidb/issues/46904
-	//tk2.MustContainErrMsg(`insert into t values (null, 6)`, "[tikv:1205]Lock wait timeout exceeded; try restarting transaction")
 	tk2.MustExec(`insert into t values (null, 6)`)
 	tk3.MustExec(`insert into ` + dbName + `2.t2 values (null, 7)`)
 	tk2.MustExec(`COMMIT`)