br: fix insert gc failed due to slow schema reload (pingcap#57742)

close pingcap#57743

(cherry picked from commit 8fe0618)

br/pkg/task/stream.go

@@ -75,6 +75,12 @@ const (
 		"You may check the metadata and continue by wait other task finish or manually delete the lock file " + truncateLockPath + " at the external storage."
 )
 
+const (
+	waitInfoSchemaReloadCheckInterval = 1 * time.Second
+	// a million tables should take a few minutes to load all DDL change, making 15 to make sure we don't exit early
+	waitInfoSchemaReloadTimeout = 15 * time.Minute
+)
+
 var (
 	StreamStart    = "log start"
 	StreamStop     = "log stop"
@@ -1450,6 +1456,21 @@ func restoreStream(
 		return errors.Annotate(err, "failed to restore kv files")
 	}
 
+	// failpoint to stop for a while after restoring kvs
+	// this is to mimic the scenario that restore takes long time and the lease in schemaInfo has expired and needs refresh
+	failpoint.Inject("post-restore-kv-pending", func(val failpoint.Value) {
+		if val.(bool) {
+			// not ideal to use sleep but not sure what's the better way right now
+			log.Info("sleep after restoring kv")
+			time.Sleep(2 * time.Second)
+		}
+	})
+
+	// make sure schema reload finishes before proceeding
+	if err = waitUntilSchemaReload(ctx, client); err != nil {
+		return errors.Trace(err)
+	}
+
 	if err = client.CleanUpKVFiles(ctx); err != nil {
 		return errors.Annotate(err, "failed to clean up")
 	}
@@ -1860,3 +1881,16 @@ func checkPiTRTaskInfo(
 
 	return curTaskInfo, doFullRestore, nil
 }
+
+func waitUntilSchemaReload(ctx context.Context, client *logclient.LogClient) error {
+	log.Info("waiting for schema info finishes reloading")
+	reloadStart := time.Now()
+	conditionFunc := func() bool {
+		return !client.GetDomain().IsLeaseExpired()
+	}
+	if err := utils.WaitUntil(ctx, conditionFunc, waitInfoSchemaReloadCheckInterval, waitInfoSchemaReloadTimeout); err != nil {
+		return errors.Annotate(err, "failed to wait until schema reload")
+	}
+	log.Info("reloading schema finished", zap.Duration("timeTaken", time.Since(reloadStart)))
+	return nil
+}

br/pkg/utils/BUILD.bazel

@@ -24,6 +24,7 @@ go_library(
         "schema.go",
         "sensitive.go",
         "store_manager.go",
+        "wait.go",
         "worker.go",
     ],
     importpath = "github.com/pingcap/tidb/br/pkg/utils",

br/pkg/utils/wait.go

@@ -0,0 +1,49 @@
+// Copyright 2024 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.
+
+package utils
+
+import (
+	"context"
+	"time"
+
+	"github.com/pingcap/errors"
+)
+
+func WaitUntil(ctx context.Context, condition func() bool, checkInterval, maxTimeout time.Duration) error {
+	// do a quick check before starting the ticker
+	if condition() {
+		return nil
+	}
+
+	timeoutCtx, cancel := context.WithTimeout(ctx, maxTimeout)
+	defer cancel()
+
+	ticker := time.NewTicker(checkInterval)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-timeoutCtx.Done():
+			if ctx.Err() != nil {
+				return ctx.Err()
+			}
+			return errors.Errorf("waitUntil timed out after waiting for %v", maxTimeout)
+		case <-ticker.C:
+			if condition() {
+				return nil
+			}
+		}
+	}
+}

br/tests/br_pitr_long_running_schema_loading/run.sh

@@ -0,0 +1,51 @@
+#!/bin/bash
+#
+# Copyright 2024 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.
+
+set -eu
+. run_services
+CUR=$(cd `dirname $0`; pwd)
+
+TASK_NAME="pitr_long_running_schema_loading"
+res_file="$TEST_DIR/sql_res.$TEST_NAME.txt"
+DB="$TEST_NAME"
+
+restart_services
+
+run_sql "CREATE SCHEMA $DB;"
+
+# start the log backup
+run_br --pd $PD_ADDR log start --task-name $TASK_NAME -s "local://$TEST_DIR/$TASK_NAME/log"
+
+run_sql "USE $DB; CREATE TABLE t1 (id INT PRIMARY KEY, value VARCHAR(255));"
+run_sql "USE $DB; INSERT INTO t1 VALUES (1, 'before-backup-1'), (2, 'before-backup-2');"
+
+
+# do a full backup
+run_br --pd "$PD_ADDR" backup full -s "local://$TEST_DIR/$TASK_NAME/full"
+
+run_sql "USE $DB; INSERT INTO t1 VALUES (3, 'after-backup-1'), (4, 'after-backup-2');"
+run_sql "USE $DB; DROP TABLE t1;"
+run_sql "USE $DB; CREATE TABLE t2 (id INT PRIMARY KEY, data TEXT);"
+run_sql "USE $DB; INSERT INTO t2 VALUES (1, 'new-table-data');"
+
+echo "wait checkpoint advance"
+. "$CUR/../br_test_utils.sh" && wait_log_checkpoint_advance $TASK_NAME
+
+restart_services
+
+export GO_FAILPOINTS="github.com/pingcap/tidb/pkg/domain/mock-load-schema-long-time=return(true);github.com/pingcap/tidb/br/pkg/task/post-restore-kv-pending=return(true)"
+run_br --pd "$PD_ADDR" restore point -s "local://$TEST_DIR/$TASK_NAME/log" --full-backup-storage "local://$TEST_DIR/$TASK_NAME/full"
+export GO_FAILPOINTS=""

br/tests/run_group.sh

@@ -22,7 +22,7 @@ declare -A groups
 groups=(
 	["G00"]="br_300_small_tables br_backup_empty br_backup_version br_cache_table br_case_sensitive br_charset_gbk br_check_new_collocation_enable"
 	["G01"]="br_autoid br_crypter2 br_db br_db_online br_db_online_newkv br_db_skip br_debug_meta br_ebs br_foreign_key br_full"
-	["G02"]="br_full_cluster_restore br_full_ddl br_full_index br_gcs br_history br_pitr_failpoint"
+	["G02"]="br_full_cluster_restore br_full_ddl br_full_index br_gcs br_history br_pitr_failpoint br_pitr_long_running_schema_loading"
 	["G03"]='br_incompatible_tidb_config br_incremental br_incremental_ddl br_incremental_index br_pitr'
 	["G04"]='br_incremental_only_ddl br_incremental_same_table br_insert_after_restore br_key_locked br_log_test br_move_backup br_mv_index br_other br_partition_add_index'
 	["G05"]='br_range br_rawkv br_replica_read br_restore_TDE_enable br_restore_log_task_enable br_s3 br_shuffle_leader br_shuffle_region br_single_table'

pkg/domain/domain.go

@@ -279,6 +279,16 @@ func (do *Domain) loadInfoSchema(startTS uint64) (infoschema.InfoSchema, bool, i
 		logutil.BgLogger().Error("failed to load schema diff", zap.Error(err))
 	}
 
+	// add failpoint to simulate long-running schema loading scenario
+	failpoint.Inject("mock-load-schema-long-time", func(val failpoint.Value) {
+		if val.(bool) {
+			// not ideal to use sleep, but not sure if there is a better way
+			logutil.BgLogger().Error("sleep before doing a full load")
+			time.Sleep(15 * time.Second)
+		}
+	})
+
+	// full load.
 	schemas, err := do.fetchAllSchemasWithTables(m)
 	if err != nil {
 		return nil, false, currentSchemaVersion, nil, err
@@ -1291,6 +1301,11 @@ func (do *Domain) Init(
 	return nil
 }
 
+// IsLeaseExpired returns whether lease has expired
+func (do *Domain) IsLeaseExpired() bool {
+	return do.SchemaValidator.IsLeaseExpired()
+}
+
 // InitInfo4Test init infosync for distributed execution test.
 func (do *Domain) InitInfo4Test() {
 	infosync.MockGlobalServerInfoManagerEntry.Add(do.ddl.GetID(), do.ServerID)

pkg/domain/schema_validator.go

@@ -57,6 +57,8 @@ type SchemaValidator interface {
 	Reset()
 	// IsStarted indicates whether SchemaValidator is started.
 	IsStarted() bool
+	// IsLeaseExpired checks whether the current lease has expired
+	IsLeaseExpired() bool
 }
 
 type deltaSchemaInfo struct {
@@ -172,6 +174,10 @@ func (s *schemaValidator) Update(leaseGrantTS uint64, oldVer, currVer int64, cha
 	}
 }
 
+func (s *schemaValidator) IsLeaseExpired() bool {
+	return time.Now().After(s.latestSchemaExpire)
+}
+
 // isRelatedTablesChanged returns the result whether relatedTableIDs is changed
 // from usedVer to the latest schema version.
 // NOTE, this function should be called under lock!