Bug #25469161: MYSQLDUMP SHOULD EXCLUDE REPLICATION

               REPOSITORY METADATA TABLES

Description : Replication meta data tables such as
mysql.slave_master_info and mysql.slave_relay_log_info
gets backed up when MYSQLDUMP is executed.

Analysis:- The above mentioned replication tables should be
excluded from backups because they are not a logical part of
data. These tables contain replication channel meta data
that will leave the replication meta data in an invalid
state after the restoration of the dump.

Fix: Both the tables are excluded from MYSQLDUMP.

Author: Arun Kuruvila

client/mysqldump.c

@@ -2622,6 +2622,15 @@ static inline my_bool general_log_or_slow_log_tables(const char *db,
            !my_strcasecmp(charset_info, table, "slow_log"));
 }
 
+/* slave_master_info and slave_relay_log_info tables under mysql database */
+static inline my_bool replication_metadata_tables(const char *db,
+                                                  const char *table)
+{
+  return (!my_strcasecmp(charset_info, db, "mysql")) &&
+          (!my_strcasecmp(charset_info, table, "slave_master_info") ||
+           !my_strcasecmp(charset_info, table, "slave_relay_log_info"));
+}
+
 /*
   get_table_structure -- retrievs database structure, prints out corresponding
   CREATE statement and fills out insert_pat if the table is the type we will
@@ -2659,6 +2668,7 @@ static uint get_table_structure(char *table, char *db, char *table_type,
   FILE       *sql_file= md_result_file;
   size_t     len;
   my_bool    is_log_table;
+  my_bool    is_replication_metadata_table;
   unsigned int colno;
   MYSQL_RES  *result;
   MYSQL_ROW  row;
@@ -2737,8 +2747,10 @@ static uint get_table_structure(char *table, char *db, char *table_type,
         view-specific code below fills in the DROP VIEW.
         We will skip the DROP TABLE for general_log and slow_log, since
         those stmts will fail, in case we apply dump by enabling logging.
+        We will skip this for replication metadata tables as well.
        */
-        if (!general_log_or_slow_log_tables(db, table))
+        if (!(general_log_or_slow_log_tables(db, table) ||
+              replication_metadata_tables(db, table)))
           fprintf(sql_file, "DROP TABLE IF EXISTS %s;\n",
                   opt_quoted_table);
         check_io(sql_file);
@@ -2868,13 +2880,14 @@ static uint get_table_structure(char *table, char *db, char *table_type,
       row= mysql_fetch_row(result);
 
       is_log_table= general_log_or_slow_log_tables(db, table);
-      if (is_log_table)
+      is_replication_metadata_table= replication_metadata_tables(db, table);
+      if (is_log_table || is_replication_metadata_table)
         row[1]+= 13; /* strlen("CREATE TABLE ")= 13 */
       if (opt_compatible_mode & 3)
       {
         fprintf(sql_file,
-                is_log_table ? "CREATE TABLE IF NOT EXISTS %s;\n" : "%s;\n",
-                row[1]);
+                (is_log_table || is_replication_metadata_table) ?
+                "CREATE TABLE IF NOT EXISTS %s;\n" : "%s;\n", row[1]);
       }
       else
       {
@@ -2883,8 +2896,8 @@ static uint get_table_structure(char *table, char *db, char *table_type,
                 "/*!40101 SET character_set_client = utf8 */;\n"
                 "%s%s;\n"
                 "/*!40101 SET character_set_client = @saved_cs_client */;\n",
-                is_log_table ? "CREATE TABLE IF NOT EXISTS " : "",
-                row[1]);
+                (is_log_table || is_replication_metadata_table) ?
+                "CREATE TABLE IF NOT EXISTS " : "", row[1]);
       }
 
       check_io(sql_file);
@@ -3622,6 +3635,12 @@ static void dump_table(char *table, char *db)
   if (strcmp(table_type, "VIEW") == 0)
     DBUG_VOID_RETURN;
 
+  /*
+    We don't dump data fo`r replication metadata tables.
+  */
+  if (replication_metadata_tables(db, table))
+    DBUG_VOID_RETURN;
+
   /* Check --no-data flag */
   if (opt_no_data)
   {

mysql-test/r/mysqldump.result

@@ -5589,3 +5589,96 @@ ROUTINE_NAME
 proc
 one
 DROP DATABASE bug25717383;
+#
+# Bug #25469161: MYSQLDUMP SHOULD EXCLUDE REPLICATION
+#                REPOSITORY METADATA TABLES
+#
+SHOW VARIABLES LIKE "master_info_repository";
+Variable_name	Value
+master_info_repository	FILE
+SHOW VARIABLES LIKE "relay_log_info_repository";
+Variable_name	Value
+relay_log_info_repository	FILE
+SET GLOBAL master_info_repository= 'TABLE';
+SET GLOBAL relay_log_info_repository= 'TABLE';
+SHOW VARIABLES LIKE "master_info_repository";
+Variable_name	Value
+master_info_repository	TABLE
+SHOW VARIABLES LIKE "relay_log_info_repository";
+Variable_name	Value
+relay_log_info_repository	TABLE
+
+/*!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 */;
+/*!40101 SET @saved_cs_client     = @@character_set_client */;
+/*!40101 SET character_set_client = utf8 */;
+CREATE TABLE IF NOT EXISTS `slave_master_info` (
+  `Number_of_lines` int(10) unsigned NOT NULL COMMENT 'Number of lines in the file.',
+  `Master_log_name` text CHARACTER SET utf8 COLLATE utf8_bin NOT NULL COMMENT 'The name of the master binary log currently being read from the master.',
+  `Master_log_pos` bigint(20) unsigned NOT NULL COMMENT 'The master log position of the last read event.',
+  `Host` char(64) CHARACTER SET utf8 COLLATE utf8_bin DEFAULT NULL COMMENT 'The host name of the master.',
+  `User_name` text CHARACTER SET utf8 COLLATE utf8_bin COMMENT 'The user name used to connect to the master.',
+  `User_password` text CHARACTER SET utf8 COLLATE utf8_bin COMMENT 'The password used to connect to the master.',
+  `Port` int(10) unsigned NOT NULL COMMENT 'The network port used to connect to the master.',
+  `Connect_retry` int(10) unsigned NOT NULL COMMENT 'The period (in seconds) that the slave will wait before trying to reconnect to the master.',
+  `Enabled_ssl` tinyint(1) NOT NULL COMMENT 'Indicates whether the server supports SSL connections.',
+  `Ssl_ca` text CHARACTER SET utf8 COLLATE utf8_bin COMMENT 'The file used for the Certificate Authority (CA) certificate.',
+  `Ssl_capath` text CHARACTER SET utf8 COLLATE utf8_bin COMMENT 'The path to the Certificate Authority (CA) certificates.',
+  `Ssl_cert` text CHARACTER SET utf8 COLLATE utf8_bin COMMENT 'The name of the SSL certificate file.',
+  `Ssl_cipher` text CHARACTER SET utf8 COLLATE utf8_bin COMMENT 'The name of the cipher in use for the SSL connection.',
+  `Ssl_key` text CHARACTER SET utf8 COLLATE utf8_bin COMMENT 'The name of the SSL key file.',
+  `Ssl_verify_server_cert` tinyint(1) NOT NULL COMMENT 'Whether to verify the server certificate.',
+  `Heartbeat` float NOT NULL,
+  `Bind` text CHARACTER SET utf8 COLLATE utf8_bin COMMENT 'Displays which interface is employed when connecting to the MySQL server',
+  `Ignored_server_ids` text CHARACTER SET utf8 COLLATE utf8_bin COMMENT 'The number of server IDs to be ignored, followed by the actual server IDs',
+  `Uuid` text CHARACTER SET utf8 COLLATE utf8_bin COMMENT 'The master server uuid.',
+  `Retry_count` bigint(20) unsigned NOT NULL COMMENT 'Number of reconnect attempts, to the master, before giving up.',
+  `Ssl_crl` text CHARACTER SET utf8 COLLATE utf8_bin COMMENT 'The file used for the Certificate Revocation List (CRL)',
+  `Ssl_crlpath` text CHARACTER SET utf8 COLLATE utf8_bin COMMENT 'The path used for Certificate Revocation List (CRL) files',
+  `Enabled_auto_position` tinyint(1) NOT NULL COMMENT 'Indicates whether GTIDs will be used to retrieve events from the master.',
+  `Channel_name` char(64) NOT NULL COMMENT 'The channel on which the slave is connected to a source. Used in Multisource Replication',
+  `Tls_version` text CHARACTER SET utf8 COLLATE utf8_bin COMMENT 'Tls version',
+  PRIMARY KEY (`Channel_name`)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8 STATS_PERSISTENT=0 COMMENT='Master Information';
+/*!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 `slave_relay_log_info` (
+  `Number_of_lines` int(10) unsigned NOT NULL COMMENT 'Number of lines in the file or rows in the table. Used to version table definitions.',
+  `Relay_log_name` text CHARACTER SET utf8 COLLATE utf8_bin NOT NULL COMMENT 'The name of the current relay log file.',
+  `Relay_log_pos` bigint(20) unsigned NOT NULL COMMENT 'The relay log position of the last executed event.',
+  `Master_log_name` text CHARACTER SET utf8 COLLATE utf8_bin NOT NULL COMMENT 'The name of the master binary log file from which the events in the relay log file were read.',
+  `Master_log_pos` bigint(20) unsigned NOT NULL COMMENT 'The master log position of the last executed event.',
+  `Sql_delay` int(11) NOT NULL COMMENT 'The number of seconds that the slave must lag behind the master.',
+  `Number_of_workers` int(10) unsigned NOT NULL,
+  `Id` int(10) unsigned NOT NULL COMMENT 'Internal Id that uniquely identifies this record.',
+  `Channel_name` char(64) NOT NULL COMMENT 'The channel on which the slave is connected to a source. Used in Multisource Replication',
+  PRIMARY KEY (`Channel_name`)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8 STATS_PERSISTENT=0 COMMENT='Relay Log Information';
+/*!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 */;
+
+SET GLOBAL master_info_repository= 'FILE';
+SET GLOBAL relay_log_info_repository= 'FILE';
+SHOW VARIABLES LIKE "master_info_repository";
+Variable_name	Value
+master_info_repository	FILE
+SHOW VARIABLES LIKE "relay_log_info_repository";
+Variable_name	Value
+relay_log_info_repository	FILE

mysql-test/suite/rpl/t/rpl_alter_repository.test

@@ -262,7 +262,7 @@ perl;
   use strict;
   my $outf= $ENV{'OUTF'} or die "OUTF not set";
   open(FILE, "$outf") or die("Unable to open $outf: $!\n");
-  my $count = () = grep(/CREATE TABLE `slave_master_info`/gi,<FILE>);
+  my $count = () = grep(/CREATE TABLE IF NOT EXISTS `slave_master_info`/gi,<FILE>);
   print "- Occurrences: $count\n";
   close(FILE);
 EOF

mysql-test/t/mysqldump.test

@@ -2697,3 +2697,25 @@ SELECT ROUTINE_NAME FROM INFORMATION_SCHEMA.ROUTINES
        ORDER BY ROUTINE_NAME;
 
 DROP DATABASE bug25717383;
+
+--echo #
+--echo # Bug #25469161: MYSQLDUMP SHOULD EXCLUDE REPLICATION
+--echo #                REPOSITORY METADATA TABLES
+--echo #
+
+SHOW VARIABLES LIKE "master_info_repository";
+SHOW VARIABLES LIKE "relay_log_info_repository";
+
+SET GLOBAL master_info_repository= 'TABLE';
+SET GLOBAL relay_log_info_repository= 'TABLE';
+
+SHOW VARIABLES LIKE "master_info_repository";
+SHOW VARIABLES LIKE "relay_log_info_repository";
+
+--exec $MYSQL_DUMP --skip-comments mysql slave_master_info slave_relay_log_info 2>&1
+
+SET GLOBAL master_info_repository= 'FILE';
+SET GLOBAL relay_log_info_repository= 'FILE';
+
+SHOW VARIABLES LIKE "master_info_repository";
+SHOW VARIABLES LIKE "relay_log_info_repository";