restore: support restore empty databases and tables (pingcap#317)

kennytm · May 28, 2020 · 2bd3248 · 2bd3248
1 parent bc21c31
commit 2bd3248
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Showing 2 changed files with 32 additions and 4 deletions.
diff --git a/pkg/task/restore.go b/pkg/task/restore.go
@@ -171,8 +171,8 @@ func RunRestore(c context.Context, g glue.Glue, cmdName string, cfg *RestoreConf
 	}
 
 	// nothing to restore, maybe only ddl changes in incremental restore
-	if len(files) == 0 {
-		log.Info("all files are filtered out from the backup archive, nothing to restore")
+	if len(dbs) == 0 && len(tables) == 0 {
+		log.Info("nothing to restore, all databases and tables are filtered out")
 		// even nothing to restore, we show a success message since there is no failure.
 		summary.SetSuccessStatus(true)
 		return nil
@@ -189,6 +189,12 @@ func RunRestore(c context.Context, g glue.Glue, cmdName string, cfg *RestoreConf
 	if err != nil {
 		return err
 	}
+	if len(files) == 0 {
+		log.Info("no files, empty databases and tables are restored")
+		summary.SetSuccessStatus(true)
+		return nil
+	}
+
 	placementRules, err := client.GetPlacementRules(cfg.PD)
 	if err != nil {
 		return err
@@ -341,6 +347,9 @@ func filterRestoreFiles(
 			tables = append(tables, table)
 		}
 	}
+	if len(dbs) == 0 && len(tables) != 0 {
+		err = errors.New("invalid backup, contain tables but no databases")
+	}
 	return
 }
 

diff --git a/tests/br_backup_empty/run.sh b/tests/br_backup_empty/run.sh
@@ -14,21 +14,40 @@
 # limitations under the License.
 
 set -eu
+DB="$TEST_NAME"
 
 # backup empty.
 echo "backup start..."
-run_br --pd $PD_ADDR backup full -s "local://$TEST_DIR/empty" --ratelimit 5 --concurrency 4
+run_br --pd $PD_ADDR backup full -s "local://$TEST_DIR/empty_db" --ratelimit 5 --concurrency 4
 if [ $? -ne 0 ]; then
     echo "TEST: [$TEST_NAME] failed on backup empty cluster!"
     exit 1
 fi
 
 # restore empty.
 echo "restore start..."
-run_br restore full -s "local://$TEST_DIR/empty" --pd $PD_ADDR --ratelimit 1024
+run_br restore full -s "local://$TEST_DIR/empty_db" --pd $PD_ADDR --ratelimit 1024
 if [ $? -ne 0 ]; then
     echo "TEST: [$TEST_NAME] failed on restore empty cluster!"
     exit 1
 fi
 
+# backup and restore empty tables.
+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;"
+
+echo "backup start..."
+run_br --pd $PD_ADDR backup full -s "local://$TEST_DIR/empty_table" --ratelimit 5 --concurrency 4
+
+run_sql "DROP DATABASE $DB;"
+echo "restore start..."
+run_br --pd $PD_ADDR restore full -s "local://$TEST_DIR/empty_table" --ratelimit 5 --concurrency 4
+
+# insert one row to make sure table is restored.
+run_sql "INSERT INTO $DB.usertable1 VALUES (\"a\", \"b\");"
+
 echo "TEST: [$TEST_NAME] successed!"