br: make table existence check unified on different br client (#58211)

br/pkg/task/BUILD.bazel

@@ -43,6 +43,7 @@ go_library(
         "//br/pkg/version",
         "//config",
         "//ddl",
+        "//infoschema",
         "//kv",
         "//parser/model",
         "//parser/mysql",

br/pkg/task/restore.go

@@ -4,6 +4,7 @@ package task
 
 import (
 	"context"
+	"fmt"
 	"strings"
 	"time"
 
@@ -26,6 +27,7 @@ import (
 	"github.com/pingcap/tidb/br/pkg/utils"
 	"github.com/pingcap/tidb/br/pkg/version"
 	"github.com/pingcap/tidb/config"
+	"github.com/pingcap/tidb/infoschema"
 	"github.com/pingcap/tidb/util"
 	"github.com/pingcap/tidb/util/mathutil"
 	"github.com/spf13/cobra"
@@ -627,6 +629,10 @@ func runRestore(c context.Context, g glue.Glue, cmdName string, cfg *RestoreConf
 		if err = client.CheckSysTableCompatibility(mgr.GetDomain(), tables); err != nil {
 			return errors.Trace(err)
 		}
+	} else if !client.IsIncremental() && cfg.CheckRequirements {
+		if err := checkTableExistence(ctx, mgr, tables, g); err != nil {
+			return errors.Trace(err)
+		}
 	}
 
 	sp := utils.BRServiceSafePoint{
@@ -846,6 +852,24 @@ func runRestore(c context.Context, g glue.Glue, cmdName string, cfg *RestoreConf
 	return nil
 }
 
+func checkTableExistence(ctx context.Context, mgr *conn.Mgr, tables []*metautil.Table, g glue.Glue) error {
+	message := "table already exists: "
+	allUnique := true
+	for _, table := range tables {
+		_, err := mgr.GetDomain().InfoSchema().TableByName(table.DB.Name, table.Info.Name)
+		if err == nil {
+			message += fmt.Sprintf("%s.%s ", table.DB.Name, table.Info.Name)
+			allUnique = false
+		} else if !infoschema.ErrTableNotExists.Equal(err) {
+			return errors.Trace(err)
+		}
+	}
+	if !allUnique {
+		return fmt.Errorf(message)
+	}
+	return nil
+}
+
 // dropToBlackhole drop all incoming tables into black hole,
 // i.e. don't execute checksum, just increase the process anyhow.
 func dropToBlackhole(

br/tests/br_300_small_tables/run.sh

@@ -73,16 +73,15 @@ else
 fi
 
 # truncate every table
-# (FIXME: drop instead of truncate. if we drop then create-table will still be executed and wastes time executing DDLs)
 i=1
 while [ $i -le $TABLES_COUNT ]; do
-    run_sql "truncate $DB.sbtest$i;"
+    run_sql "drop table $DB.sbtest$i;"
     i=$(($i+1))
 done
 
 rm -rf $RESTORE_LOG
 echo "restore 1/300 of the table start..."
-run_br restore table --db $DB  --table "sbtest100" --log-file $RESTORE_LOG -s "local://$TEST_DIR/$DB" --pd $PD_ADDR --no-schema
+run_br restore table --db $DB  --table "sbtest100" --log-file $RESTORE_LOG -s "local://$TEST_DIR/$DB" --pd $PD_ADDR
 restore_size=`grep "restore-data-size" "${RESTORE_LOG}" | grep -oP '\[\K[^\]]+' | grep "restore-data-size" | awk -F '=' '{print $2}' | grep -oP '\d*\.?\d+'`
 echo "restore data size is ${restore_size}"
 
@@ -98,9 +97,10 @@ else
     exit 1 
 fi
 
+run_sql "drop table $DB.sbtest100;"
+
 # restore db
-# (FIXME: shouldn't need --no-schema to be fast, currently the alter-auto-id DDL slows things down)
 echo "restore start..."
-run_br restore db --db $DB -s "local://$TEST_DIR/$DB" --pd $PD_ADDR --no-schema
+run_br restore db --db $DB -s "local://$TEST_DIR/$DB" --pd $PD_ADDR
 
 run_sql "DROP DATABASE $DB;"

br/tests/br_check_dup_table/run.sh

@@ -0,0 +1,68 @@
+#!/bin/sh
+#
+# 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
+DB="$TEST_NAME"
+
+run_sql "CREATE DATABASE $DB;"
+
+run_sql "CREATE TABLE $DB.usertable1 ( \
+  YCSB_KEY varchar(64) NOT NULL, \
+  FIELD0 varchar(1) DEFAULT NULL, \
+  PRIMARY KEY (YCSB_KEY) \
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin;"
+
+run_sql "INSERT INTO $DB.usertable1 VALUES (\"a\", \"b\");"
+run_sql "INSERT INTO $DB.usertable1 VALUES (\"aa\", \"b\");"
+
+run_sql "CREATE TABLE $DB.usertable2 ( \
+  YCSB_KEY varchar(64) NOT NULL, \
+  FIELD0 varchar(1) DEFAULT NULL, \
+  PRIMARY KEY (YCSB_KEY) \
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin;"
+
+run_sql "INSERT INTO $DB.usertable2 VALUES (\"c\", \"d\");"
+# backup db
+echo "backup start..."
+run_br --pd $PD_ADDR backup db --db "$DB" -s "local://$TEST_DIR/$DB"
+
+run_sql "DROP DATABASE $DB;"
+
+# restore db
+echo "restore start..."
+run_br restore db --db $DB -s "local://$TEST_DIR/$DB" --pd $PD_ADDR
+
+table_count=$(run_sql "use $DB; show tables;" | grep "Tables_in" | wc -l)
+if [ "$table_count" -ne "2" ];then
+    echo "TEST: [$TEST_NAME] failed!"
+    exit 1
+fi
+
+# restore db again
+echo "restore start..."
+LOG_OUTPUT=$(run_br restore db --db "$DB" -s "local://$TEST_DIR/$DB" --pd "$PD_ADDR" 2>&1 || true)
+
+# Check if the log contains 'ErrTableAlreadyExisted'
+if ! echo "$LOG_OUTPUT" | grep -q "BR:Restore:ErrTablesAlreadyExisted"; then
+    echo "Error: 'ErrTableAlreadyExisted' not found in logs."
+    echo "Log output:"
+    echo "$LOG_OUTPUT"
+    exit 1
+else
+    echo "restore failed as expect" 
+fi
+
+run_sql "DROP DATABASE $DB;"

br/tests/br_incompatible_tidb_config/run.sh

@@ -54,14 +54,14 @@ run_br --pd $PD_ADDR backup db --db "$DB" -s "local://$TEST_DIR/$DB$INCREMENTAL_
 run_sql "drop schema $DB;"
 # restore with ddl(create table) job one by one
 run_br --pd $PD_ADDR restore db --db "$DB" -s "local://$TEST_DIR/$DB$TABLE" --ddl-batch-size=1
-
+run_sql "drop schema $DB;"
 run_br --pd $PD_ADDR restore db --db "$DB" -s "local://$TEST_DIR/$DB$INCREMENTAL_TABLE" --ddl-batch-size=1
 
 # restore
 run_sql "drop schema $DB;"
 # restore with batch create table
 run_br --pd $PD_ADDR restore db --db "$DB" -s "local://$TEST_DIR/$DB$TABLE" --ddl-batch-size=128
-
+run_sql "drop schema $DB;"
 run_br --pd $PD_ADDR restore db --db "$DB" -s "local://$TEST_DIR/$DB$INCREMENTAL_TABLE" --ddl-batch-size=128
 
 run_sql "drop schema $DB;"