From bf7c3efbd79424a5d778ea91c284e203247f4465 Mon Sep 17 00:00:00 2001
From: 3pointer <luancheng@pingcap.com>
Date: Tue, 10 May 2022 16:32:34 +0800
Subject: [PATCH] backup: fix the lost empty database (#34519)

ref pingcap/tidb#33866
---
 br/docker/Dockerfile            |  4 ++--
 br/pkg/metautil/metafile.go     |  2 +-
 br/tests/br_backup_empty/run.sh | 28 ++++++++++++++++++++++------
 3 files changed, 25 insertions(+), 9 deletions(-)

diff --git a/br/docker/Dockerfile b/br/docker/Dockerfile
index 73d19247a6..38e67e34b8 100644
--- a/br/docker/Dockerfile
+++ b/br/docker/Dockerfile
@@ -1,5 +1,5 @@
 # For loading data to TiDB
-FROM golang:1.16.4-buster as go-ycsb-builder
+FROM golang:1.18-buster as go-ycsb-builder
 WORKDIR /go/src/github.com/pingcap/
 RUN git clone https://github.com/pingcap/go-ycsb.git --depth=1 && \
     cd go-ycsb && \
@@ -8,7 +8,7 @@ RUN git clone https://github.com/pingcap/go-ycsb.git --depth=1 && \
 # For operating minio S3 compatible storage
 FROM minio/mc as mc-builder
 
-FROM golang:1.16.4-buster
+FROM golang:1.18-buster
 
 RUN apt-get update && apt-get install -y --no-install-recommends \
     git \
diff --git a/br/pkg/metautil/metafile.go b/br/pkg/metautil/metafile.go
index 5d24df35a3..6cf5b292df 100644
--- a/br/pkg/metautil/metafile.go
+++ b/br/pkg/metautil/metafile.go
@@ -335,7 +335,7 @@ func (reader *MetaReader) ReadSchemasFiles(ctx context.Context, output chan<- *T
 				tableMap[tableInfo.ID] = table
 			} else {
 				// empty database
-				tableMap[0] = table
+				tableMap[dbInfo.ID] = table
 			}
 			return nil
 		})
diff --git a/br/tests/br_backup_empty/run.sh b/br/tests/br_backup_empty/run.sh
index 42d910f41f..41ca818139 100644
--- a/br/tests/br_backup_empty/run.sh
+++ b/br/tests/br_backup_empty/run.sh
@@ -16,6 +16,7 @@
 
 set -eu
 DB="$TEST_NAME"
+DB_COUNT=10
 
 # backup empty.
 echo "backup empty cluster start..."
@@ -34,7 +35,12 @@ if [ $? -ne 0 ]; then
 fi
 
 # backup and restore empty tables.
-run_sql "CREATE DATABASE $DB;"
+i=1
+while [ $i -le $DB_COUNT ]; do
+    run_sql "CREATE DATABASE $DB$i;"
+    i=$(($i+1))
+done
+
 echo "backup empty db start..."
 run_br --pd $PD_ADDR backup full -s "local://$TEST_DIR/empty_db"
 if [ $? -ne 0 ]; then
@@ -42,7 +48,10 @@ if [ $? -ne 0 ]; then
     exit 1
 fi
 
-run_sql "DROP DATABASE $DB"
+while [ $i -le $DB_COUNT ]; do
+    run_sql "DROP DATABASE $DB$i;"
+    i=$(($i+1))
+done
 
 # restore empty.
 echo "restore empty db start..."
@@ -52,7 +61,7 @@ if [ $? -ne 0 ]; then
     exit 1
 fi
 
-run_sql "CREATE TABLE $DB.usertable1 ( \
+run_sql "CREATE TABLE ${DB}1.usertable1 ( \
   YCSB_KEY varchar(64) NOT NULL, \
   FIELD0 varchar(1) DEFAULT NULL, \
   PRIMARY KEY (YCSB_KEY) \
@@ -61,11 +70,18 @@ run_sql "CREATE TABLE $DB.usertable1 ( \
 echo "backup empty table start..."
 run_br --pd $PD_ADDR backup full -s "local://$TEST_DIR/empty_table"
 
-run_sql "DROP DATABASE $DB;"
+while [ $i -le $DB_COUNT ]; do
+    run_sql "DROP DATABASE $DB$i;"
+    i=$(($i+1))
+done
+
 echo "restore empty table start..."
 run_br --pd $PD_ADDR restore full -s "local://$TEST_DIR/empty_table"
 
 # insert one row to make sure table is restored.
-run_sql "INSERT INTO $DB.usertable1 VALUES (\"a\", \"b\");"
+run_sql "INSERT INTO ${DB}1.usertable1 VALUES (\"a\", \"b\");"
 
-run_sql "DROP DATABASE $DB"
+while [ $i -le $DB_COUNT ]; do
+    run_sql "DROP DATABASE $DB$i;"
+    i=$(($i+1))
+done