MDEV-20939: Race condition between mysqldump import and InnoDB persistent

statistics calculation

 Analysis: When --replace or --insert-ignore is not given, dumping of
mysql.innodb_index_stats and mysql.innodb_table_stats will result into race
condition.
Fix: Check if these options are present with --system=stats (because dumping
under --system=stats is safe). Otherwise, dump only structure, ignoring data
because innodb will recalculate data anyway.

3 files changed, 304 insertions, 0 deletions

diff --git a/client/mysqldump.c b/client/mysqldump.c
index 2eaec829867..ecca380777f 100644
--- a/client/mysqldump.c
+++ b/client/mysqldump.c
@@ -1052,6 +1052,20 @@ static int get_options(int *argc, char ***argv)
   if ((ho_error= handle_options(argc, argv, my_long_options, get_one_option)))
     return(ho_error);
 
+  /*
+    Dumping under --system=stats with --replace or --inser-ignore is safe and will not
+    retult into race condition. Otherwise dump only structure and ignore data by default
+    while dumping.
+  */
+  if (!(opt_system & OPT_SYSTEM_STATS) && !(opt_ignore || opt_replace_into))
+  {
+    if (my_hash_insert(&ignore_data,
+                       (uchar*) my_strdup("mysql.innodb_index_stats", MYF(MY_WME))) ||
+        my_hash_insert(&ignore_data,
+                       (uchar*) my_strdup("mysql.innodb_table_stats", MYF(MY_WME))))
+      return(EX_EOM);
+  }
+
   if (opt_system & OPT_SYSTEM_ALL)
       opt_system|= ~0;
 
diff --git a/mysql-test/r/mysqldump.result b/mysql-test/r/mysqldump.result
index 974ff200e68..da80ff09db9 100644
--- a/mysql-test/r/mysqldump.result
+++ b/mysql-test/r/mysqldump.result
@@ -5714,4 +5714,271 @@ DELIMITER ;
 /*!40111 SET SQL_NOTES=@OLD_SQL_NOTES */;
 
 DROP TABLE t1;
+#
+# MDEV-20939: Race condition between mysqldump import and InnoDB
+#             persistent statistics calculation
+#
+#
+# Without --replace and --insert-ignore
+#
+
+/*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT */;
+/*!40101 SET @OLD_CHARACTER_SET_RESULTS=@@CHARACTER_SET_RESULTS */;
+/*!40101 SET @OLD_COLLATION_CONNECTION=@@COLLATION_CONNECTION */;
+/*!40101 SET NAMES utf8 */;
+/*!40103 SET @OLD_TIME_ZONE=@@TIME_ZONE */;
+/*!40103 SET TIME_ZONE='+00:00' */;
+/*!40014 SET @OLD_UNIQUE_CHECKS=@@UNIQUE_CHECKS, UNIQUE_CHECKS=0 */;
+/*!40014 SET @OLD_FOREIGN_KEY_CHECKS=@@FOREIGN_KEY_CHECKS, FOREIGN_KEY_CHECKS=0 */;
+/*!40101 SET @OLD_SQL_MODE=@@SQL_MODE, SQL_MODE='NO_AUTO_VALUE_ON_ZERO' */;
+/*!40111 SET @OLD_SQL_NOTES=@@SQL_NOTES, SQL_NOTES=0 */;
+DROP TABLE IF EXISTS `innodb_index_stats`;
+/*!40101 SET @saved_cs_client     = @@character_set_client */;
+/*!40101 SET character_set_client = utf8 */;
+CREATE TABLE `innodb_index_stats` (
+  `database_name` varchar(64) COLLATE utf8_bin NOT NULL,
+  `table_name` varchar(199) COLLATE utf8_bin NOT NULL,
+  `index_name` varchar(64) COLLATE utf8_bin NOT NULL,
+  `last_update` timestamp NOT NULL DEFAULT current_timestamp() ON UPDATE current_timestamp(),
+  `stat_name` varchar(64) COLLATE utf8_bin NOT NULL,
+  `stat_value` bigint(20) unsigned NOT NULL,
+  `sample_size` bigint(20) unsigned DEFAULT NULL,
+  `stat_description` varchar(1024) COLLATE utf8_bin NOT NULL,
+  PRIMARY KEY (`database_name`,`table_name`,`index_name`,`stat_name`)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin STATS_PERSISTENT=0;
+/*!40101 SET character_set_client = @saved_cs_client */;
+DROP TABLE IF EXISTS `innodb_table_stats`;
+/*!40101 SET @saved_cs_client     = @@character_set_client */;
+/*!40101 SET character_set_client = utf8 */;
+CREATE TABLE `innodb_table_stats` (
+  `database_name` varchar(64) COLLATE utf8_bin NOT NULL,
+  `table_name` varchar(199) COLLATE utf8_bin NOT NULL,
+  `last_update` timestamp NOT NULL DEFAULT current_timestamp() ON UPDATE current_timestamp(),
+  `n_rows` bigint(20) unsigned NOT NULL,
+  `clustered_index_size` bigint(20) unsigned NOT NULL,
+  `sum_of_other_index_sizes` bigint(20) unsigned NOT NULL,
+  PRIMARY KEY (`database_name`,`table_name`)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin STATS_PERSISTENT=0;
+/*!40101 SET character_set_client = @saved_cs_client */;
+/*!40101 SET @saved_cs_client     = @@character_set_client */;
+/*!40101 SET character_set_client = utf8 */;
+CREATE TABLE IF NOT EXISTS `general_log` (
+  `event_time` timestamp(6) NOT NULL DEFAULT current_timestamp(6) ON UPDATE current_timestamp(6),
+  `user_host` mediumtext NOT NULL,
+  `thread_id` bigint(21) unsigned NOT NULL,
+  `server_id` int(10) unsigned NOT NULL,
+  `command_type` varchar(64) NOT NULL,
+  `argument` mediumtext NOT NULL
+) ENGINE=CSV DEFAULT CHARSET=utf8 COMMENT='General log';
+/*!40101 SET character_set_client = @saved_cs_client */;
+/*!40101 SET @saved_cs_client     = @@character_set_client */;
+/*!40101 SET character_set_client = utf8 */;
+CREATE TABLE IF NOT EXISTS `slow_log` (
+  `start_time` timestamp(6) NOT NULL DEFAULT current_timestamp(6) ON UPDATE current_timestamp(6),
+  `user_host` mediumtext NOT NULL,
+  `query_time` time(6) NOT NULL,
+  `lock_time` time(6) NOT NULL,
+  `rows_sent` int(11) NOT NULL,
+  `rows_examined` int(11) NOT NULL,
+  `db` varchar(512) NOT NULL,
+  `last_insert_id` int(11) NOT NULL,
+  `insert_id` int(11) NOT NULL,
+  `server_id` int(10) unsigned NOT NULL,
+  `sql_text` mediumtext NOT NULL,
+  `thread_id` bigint(21) unsigned NOT NULL,
+  `rows_affected` int(11) NOT NULL
+) ENGINE=CSV DEFAULT CHARSET=utf8 COMMENT='Slow log';
+/*!40101 SET character_set_client = @saved_cs_client */;
+/*!40103 SET TIME_ZONE=@OLD_TIME_ZONE */;
+
+/*!40101 SET SQL_MODE=@OLD_SQL_MODE */;
+/*!40014 SET FOREIGN_KEY_CHECKS=@OLD_FOREIGN_KEY_CHECKS */;
+/*!40014 SET UNIQUE_CHECKS=@OLD_UNIQUE_CHECKS */;
+/*!40101 SET CHARACTER_SET_CLIENT=@OLD_CHARACTER_SET_CLIENT */;
+/*!40101 SET CHARACTER_SET_RESULTS=@OLD_CHARACTER_SET_RESULTS */;
+/*!40101 SET COLLATION_CONNECTION=@OLD_COLLATION_CONNECTION */;
+/*!40111 SET SQL_NOTES=@OLD_SQL_NOTES */;
+
+#
+# With --replace
+#
+
+/*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT */;
+/*!40101 SET @OLD_CHARACTER_SET_RESULTS=@@CHARACTER_SET_RESULTS */;
+/*!40101 SET @OLD_COLLATION_CONNECTION=@@COLLATION_CONNECTION */;
+/*!40101 SET NAMES utf8 */;
+/*!40103 SET @OLD_TIME_ZONE=@@TIME_ZONE */;
+/*!40103 SET TIME_ZONE='+00:00' */;
+/*!40014 SET @OLD_UNIQUE_CHECKS=@@UNIQUE_CHECKS, UNIQUE_CHECKS=0 */;
+/*!40014 SET @OLD_FOREIGN_KEY_CHECKS=@@FOREIGN_KEY_CHECKS, FOREIGN_KEY_CHECKS=0 */;
+/*!40101 SET @OLD_SQL_MODE=@@SQL_MODE, SQL_MODE='NO_AUTO_VALUE_ON_ZERO' */;
+/*!40111 SET @OLD_SQL_NOTES=@@SQL_NOTES, SQL_NOTES=0 */;
+DROP TABLE IF EXISTS `innodb_index_stats`;
+/*!40101 SET @saved_cs_client     = @@character_set_client */;
+/*!40101 SET character_set_client = utf8 */;
+CREATE TABLE `innodb_index_stats` (
+  `database_name` varchar(64) COLLATE utf8_bin NOT NULL,
+  `table_name` varchar(199) COLLATE utf8_bin NOT NULL,
+  `index_name` varchar(64) COLLATE utf8_bin NOT NULL,
+  `last_update` timestamp NOT NULL DEFAULT current_timestamp() ON UPDATE current_timestamp(),
+  `stat_name` varchar(64) COLLATE utf8_bin NOT NULL,
+  `stat_value` bigint(20) unsigned NOT NULL,
+  `sample_size` bigint(20) unsigned DEFAULT NULL,
+  `stat_description` varchar(1024) COLLATE utf8_bin NOT NULL,
+  PRIMARY KEY (`database_name`,`table_name`,`index_name`,`stat_name`)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin STATS_PERSISTENT=0;
+/*!40101 SET character_set_client = @saved_cs_client */;
+
+LOCK TABLES `innodb_index_stats` WRITE;
+/*!40000 ALTER TABLE `innodb_index_stats` DISABLE KEYS */;
+/*!40000 ALTER TABLE `innodb_index_stats` ENABLE KEYS */;
+UNLOCK TABLES;
+DROP TABLE IF EXISTS `innodb_table_stats`;
+/*!40101 SET @saved_cs_client     = @@character_set_client */;
+/*!40101 SET character_set_client = utf8 */;
+CREATE TABLE `innodb_table_stats` (
+  `database_name` varchar(64) COLLATE utf8_bin NOT NULL,
+  `table_name` varchar(199) COLLATE utf8_bin NOT NULL,
+  `last_update` timestamp NOT NULL DEFAULT current_timestamp() ON UPDATE current_timestamp(),
+  `n_rows` bigint(20) unsigned NOT NULL,
+  `clustered_index_size` bigint(20) unsigned NOT NULL,
+  `sum_of_other_index_sizes` bigint(20) unsigned NOT NULL,
+  PRIMARY KEY (`database_name`,`table_name`)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin STATS_PERSISTENT=0;
+/*!40101 SET character_set_client = @saved_cs_client */;
+
+LOCK TABLES `innodb_table_stats` WRITE;
+/*!40000 ALTER TABLE `innodb_table_stats` DISABLE KEYS */;
+/*!40000 ALTER TABLE `innodb_table_stats` ENABLE KEYS */;
+UNLOCK TABLES;
+/*!40101 SET @saved_cs_client     = @@character_set_client */;
+/*!40101 SET character_set_client = utf8 */;
+CREATE TABLE IF NOT EXISTS `general_log` (
+  `event_time` timestamp(6) NOT NULL DEFAULT current_timestamp(6) ON UPDATE current_timestamp(6),
+  `user_host` mediumtext NOT NULL,
+  `thread_id` bigint(21) unsigned NOT NULL,
+  `server_id` int(10) unsigned NOT NULL,
+  `command_type` varchar(64) NOT NULL,
+  `argument` mediumtext NOT NULL
+) ENGINE=CSV DEFAULT CHARSET=utf8 COMMENT='General log';
+/*!40101 SET character_set_client = @saved_cs_client */;
+/*!40101 SET @saved_cs_client     = @@character_set_client */;
+/*!40101 SET character_set_client = utf8 */;
+CREATE TABLE IF NOT EXISTS `slow_log` (
+  `start_time` timestamp(6) NOT NULL DEFAULT current_timestamp(6) ON UPDATE current_timestamp(6),
+  `user_host` mediumtext NOT NULL,
+  `query_time` time(6) NOT NULL,
+  `lock_time` time(6) NOT NULL,
+  `rows_sent` int(11) NOT NULL,
+  `rows_examined` int(11) NOT NULL,
+  `db` varchar(512) NOT NULL,
+  `last_insert_id` int(11) NOT NULL,
+  `insert_id` int(11) NOT NULL,
+  `server_id` int(10) unsigned NOT NULL,
+  `sql_text` mediumtext NOT NULL,
+  `thread_id` bigint(21) unsigned NOT NULL,
+  `rows_affected` int(11) NOT NULL
+) ENGINE=CSV DEFAULT CHARSET=utf8 COMMENT='Slow log';
+/*!40101 SET character_set_client = @saved_cs_client */;
+/*!40103 SET TIME_ZONE=@OLD_TIME_ZONE */;
+
+/*!40101 SET SQL_MODE=@OLD_SQL_MODE */;
+/*!40014 SET FOREIGN_KEY_CHECKS=@OLD_FOREIGN_KEY_CHECKS */;
+/*!40014 SET UNIQUE_CHECKS=@OLD_UNIQUE_CHECKS */;
+/*!40101 SET CHARACTER_SET_CLIENT=@OLD_CHARACTER_SET_CLIENT */;
+/*!40101 SET CHARACTER_SET_RESULTS=@OLD_CHARACTER_SET_RESULTS */;
+/*!40101 SET COLLATION_CONNECTION=@OLD_COLLATION_CONNECTION */;
+/*!40111 SET SQL_NOTES=@OLD_SQL_NOTES */;
+
+#
+# With --insert-ignore
+#
+
+/*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT */;
+/*!40101 SET @OLD_CHARACTER_SET_RESULTS=@@CHARACTER_SET_RESULTS */;
+/*!40101 SET @OLD_COLLATION_CONNECTION=@@COLLATION_CONNECTION */;
+/*!40101 SET NAMES utf8 */;
+/*!40103 SET @OLD_TIME_ZONE=@@TIME_ZONE */;
+/*!40103 SET TIME_ZONE='+00:00' */;
+/*!40014 SET @OLD_UNIQUE_CHECKS=@@UNIQUE_CHECKS, UNIQUE_CHECKS=0 */;
+/*!40014 SET @OLD_FOREIGN_KEY_CHECKS=@@FOREIGN_KEY_CHECKS, FOREIGN_KEY_CHECKS=0 */;
+/*!40101 SET @OLD_SQL_MODE=@@SQL_MODE, SQL_MODE='NO_AUTO_VALUE_ON_ZERO' */;
+/*!40111 SET @OLD_SQL_NOTES=@@SQL_NOTES, SQL_NOTES=0 */;
+DROP TABLE IF EXISTS `innodb_index_stats`;
+/*!40101 SET @saved_cs_client     = @@character_set_client */;
+/*!40101 SET character_set_client = utf8 */;
+CREATE TABLE `innodb_index_stats` (
+  `database_name` varchar(64) COLLATE utf8_bin NOT NULL,
+  `table_name` varchar(199) COLLATE utf8_bin NOT NULL,
+  `index_name` varchar(64) COLLATE utf8_bin NOT NULL,
+  `last_update` timestamp NOT NULL DEFAULT current_timestamp() ON UPDATE current_timestamp(),
+  `stat_name` varchar(64) COLLATE utf8_bin NOT NULL,
+  `stat_value` bigint(20) unsigned NOT NULL,
+  `sample_size` bigint(20) unsigned DEFAULT NULL,
+  `stat_description` varchar(1024) COLLATE utf8_bin NOT NULL,
+  PRIMARY KEY (`database_name`,`table_name`,`index_name`,`stat_name`)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin STATS_PERSISTENT=0;
+/*!40101 SET character_set_client = @saved_cs_client */;
+
+LOCK TABLES `innodb_index_stats` WRITE;
+/*!40000 ALTER TABLE `innodb_index_stats` DISABLE KEYS */;
+/*!40000 ALTER TABLE `innodb_index_stats` ENABLE KEYS */;
+UNLOCK TABLES;
+DROP TABLE IF EXISTS `innodb_table_stats`;
+/*!40101 SET @saved_cs_client     = @@character_set_client */;
+/*!40101 SET character_set_client = utf8 */;
+CREATE TABLE `innodb_table_stats` (
+  `database_name` varchar(64) COLLATE utf8_bin NOT NULL,
+  `table_name` varchar(199) COLLATE utf8_bin NOT NULL,
+  `last_update` timestamp NOT NULL DEFAULT current_timestamp() ON UPDATE current_timestamp(),
+  `n_rows` bigint(20) unsigned NOT NULL,
+  `clustered_index_size` bigint(20) unsigned NOT NULL,
+  `sum_of_other_index_sizes` bigint(20) unsigned NOT NULL,
+  PRIMARY KEY (`database_name`,`table_name`)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin STATS_PERSISTENT=0;
+/*!40101 SET character_set_client = @saved_cs_client */;
+
+LOCK TABLES `innodb_table_stats` WRITE;
+/*!40000 ALTER TABLE `innodb_table_stats` DISABLE KEYS */;
+/*!40000 ALTER TABLE `innodb_table_stats` ENABLE KEYS */;
+UNLOCK TABLES;
+/*!40101 SET @saved_cs_client     = @@character_set_client */;
+/*!40101 SET character_set_client = utf8 */;
+CREATE TABLE IF NOT EXISTS `general_log` (
+  `event_time` timestamp(6) NOT NULL DEFAULT current_timestamp(6) ON UPDATE current_timestamp(6),
+  `user_host` mediumtext NOT NULL,
+  `thread_id` bigint(21) unsigned NOT NULL,
+  `server_id` int(10) unsigned NOT NULL,
+  `command_type` varchar(64) NOT NULL,
+  `argument` mediumtext NOT NULL
+) ENGINE=CSV DEFAULT CHARSET=utf8 COMMENT='General log';
+/*!40101 SET character_set_client = @saved_cs_client */;
+/*!40101 SET @saved_cs_client     = @@character_set_client */;
+/*!40101 SET character_set_client = utf8 */;
+CREATE TABLE IF NOT EXISTS `slow_log` (
+  `start_time` timestamp(6) NOT NULL DEFAULT current_timestamp(6) ON UPDATE current_timestamp(6),
+  `user_host` mediumtext NOT NULL,
+  `query_time` time(6) NOT NULL,
+  `lock_time` time(6) NOT NULL,
+  `rows_sent` int(11) NOT NULL,
+  `rows_examined` int(11) NOT NULL,
+  `db` varchar(512) NOT NULL,
+  `last_insert_id` int(11) NOT NULL,
+  `insert_id` int(11) NOT NULL,
+  `server_id` int(10) unsigned NOT NULL,
+  `sql_text` mediumtext NOT NULL,
+  `thread_id` bigint(21) unsigned NOT NULL,
+  `rows_affected` int(11) NOT NULL
+) ENGINE=CSV DEFAULT CHARSET=utf8 COMMENT='Slow log';
+/*!40101 SET character_set_client = @saved_cs_client */;
+/*!40103 SET TIME_ZONE=@OLD_TIME_ZONE */;
+
+/*!40101 SET SQL_MODE=@OLD_SQL_MODE */;
+/*!40014 SET FOREIGN_KEY_CHECKS=@OLD_FOREIGN_KEY_CHECKS */;
+/*!40014 SET UNIQUE_CHECKS=@OLD_UNIQUE_CHECKS */;
+/*!40101 SET CHARACTER_SET_CLIENT=@OLD_CHARACTER_SET_CLIENT */;
+/*!40101 SET CHARACTER_SET_RESULTS=@OLD_CHARACTER_SET_RESULTS */;
+/*!40101 SET COLLATION_CONNECTION=@OLD_COLLATION_CONNECTION */;
+/*!40111 SET SQL_NOTES=@OLD_SQL_NOTES */;
+
 # End of 10.2 tests
diff --git a/mysql-test/t/mysqldump.test b/mysql-test/t/mysqldump.test
index 4478406b395..8249810d1e5 100644
--- a/mysql-test/t/mysqldump.test
+++ b/mysql-test/t/mysqldump.test
@@ -2735,4 +2735,27 @@ INSERT INTO t1 (a) VALUES (1),(2),(3);
 --exec $MYSQL_DUMP --default-character-set=utf8mb4 --triggers --no-data --no-create-info --add-drop-trigger --skip-comments --databases test
 DROP TABLE t1;
 
+--echo #
+--echo # MDEV-20939: Race condition between mysqldump import and InnoDB
+--echo #             persistent statistics calculation
+--echo #
+
+--let $ignore= --ignore-table=mysql.proxies_priv --ignore-table=mysql.user --ignore-table=mysql.column_stats --ignore-table=mysql.columns_priv --ignore-table=mysql.db --ignore-table=mysql.event --ignore-table=mysql.func --ignore-table=mysql.gtid_slave_pos --ignore-table=mysql.help_category --ignore-table=mysql.help_keyword --ignore-table=mysql.help_relation --ignore-table=mysql.help_topic --ignore-table=mysql.host --ignore-table=mysql.index_stats --ignore-table=mysql.plugin --ignore-table=mysql.proc --ignore-table=mysql.procs_priv --ignore-table=mysql.roles_mapping --ignore-table=mysql.servers --ignore-table=mysql.table_stats --ignore-table=mysql.tables_priv --ignore-table=mysql.time_zone --ignore-table=mysql.time_zone_leap_second --ignore-table=mysql.time_zone_name --ignore-table=mysql.time_zone_transition --ignore-table=mysql.time_zone_transition_type --ignore-table=mysql.general_log --ignore-table=mysql.slow_log
+--let $skip_opts= --skip-dump-date --skip-comments
+
+--echo #
+--echo # Without --replace and --insert-ignore
+--echo #
+--exec $MYSQL_DUMP $ignore $skip_opts mysql
+
+--echo #
+--echo # With --replace
+--echo #
+--exec $MYSQL_DUMP $ignore $skip_opts --replace mysql
+
+--echo #
+--echo # With --insert-ignore
+--echo #
+--exec $MYSQL_DUMP $ignore $skip_opts --insert-ignore mysql
+
 --echo # End of 10.2 tests