MDEV-10047: table-based master info repository

Problem:
=======
When we upgrade from "mysql" to "mariadb" if slave is using repositories as
tables their data is completely ignored and no warning is issued in error log.

Fix:
===
"mysql_upgrade" test should check for the presence of data in
"mysql.slave_master_info" and "mysql.slave_relay_log_info" tables. When tables
have some data the upgrade script should report a warning which hints users
that the data in repository tables will be ignored.

client/mysql_upgrade.c

@@ -1014,6 +1014,64 @@ static int install_used_engines(void)
   return 0;
 }
 
+static int check_slave_repositories(void)
+{
+  DYNAMIC_STRING ds_result;
+  int row_count= 0;
+  int error= 0;
+  const char *query = "SELECT COUNT(*) AS c1 FROM mysql.slave_master_info";
+
+  if (init_dynamic_string(&ds_result, "", 512, 512))
+    die("Out of memory");
+
+  run_query(query, &ds_result, TRUE);
+
+  if (ds_result.length)
+  {
+    row_count= atoi((char *)ds_result.str);
+    if (row_count)
+    {
+      fprintf(stderr,"Slave info repository compatibility check:"
+              " Found data in `mysql`.`slave_master_info` table.\n");
+      fprintf(stderr,"Warning: Content of `mysql`.`slave_master_info` table"
+              " will be ignored as MariaDB supports file based info "
+              "repository.\n");
+      error= 1;
+    }
+  }
+  dynstr_free(&ds_result);
+
+  query = "SELECT COUNT(*) AS c1 FROM mysql.slave_relay_log_info";
+
+  if (init_dynamic_string(&ds_result, "", 512, 512))
+    die("Out of memory");
+
+  run_query(query, &ds_result, TRUE);
+
+  if (ds_result.length)
+  {
+    row_count= atoi((char *)ds_result.str);
+    if (row_count)
+    {
+      fprintf(stderr, "Slave info repository compatibility check:"
+              " Found data in `mysql`.`slave_relay_log_info` table.\n");
+      fprintf(stderr, "Warning: Content of `mysql`.`slave_relay_log_info` "
+              "table will be ignored as MariaDB supports file based "
+              "repository.\n");
+      error= 1;
+    }
+  }
+  dynstr_free(&ds_result);
+  if (error)
+  {
+    fprintf(stderr,"Slave server may not possess the correct replication "
+            "metadata.\n");
+    fprintf(stderr, "Execution of CHANGE MASTER as per "
+            "`mysql`.`slave_master_info` and  `mysql`.`slave_relay_log_info` "
+            "table content is recommended.\n");
+  }
+  return 0;
+}
 
 /*
   Update all system tables in MySQL Server to current
@@ -1225,7 +1283,8 @@ int main(int argc, char **argv)
       run_mysqlcheck_views() ||
       run_sql_fix_privilege_tables() ||
       run_mysqlcheck_fixnames() ||
-      run_mysqlcheck_upgrade(FALSE))
+      run_mysqlcheck_upgrade(FALSE) ||
+      check_slave_repositories())
     die("Upgrade failed" );
 
   verbose("Phase %d/%d: Running 'FLUSH PRIVILEGES'", ++phase, phases_total);

mysql-test/main/rpl_mysql_upgrade_slave_repo_check.result

+include/master-slave.inc
+[connection master]
+********************************************************************
+* Test case1: Upgrade when repository tables have data.            *
+* mysql_upgrade script should report warnings.                     *
+********************************************************************
+connection master;
+Slave info repository compatibility check: Found data in `mysql`.`slave_master_info` table.
+Warning: Content of `mysql`.`slave_master_info` table will be ignored as MariaDB supports file based info repository.
+Slave info repository compatibility check: Found data in `mysql`.`slave_relay_log_info` table.
+Warning: Content of `mysql`.`slave_relay_log_info` table will be ignored as MariaDB supports file based repository.
+Slave server may not possess the correct replication metadata.
+Execution of CHANGE MASTER as per `mysql`.`slave_master_info` and  `mysql`.`slave_relay_log_info` table content is recommended.
+connection slave;
+Slave info repository compatibility check: Found data in `mysql`.`slave_master_info` table.
+Warning: Content of `mysql`.`slave_master_info` table will be ignored as MariaDB supports file based info repository.
+Slave info repository compatibility check: Found data in `mysql`.`slave_relay_log_info` table.
+Warning: Content of `mysql`.`slave_relay_log_info` table will be ignored as MariaDB supports file based repository.
+Slave server may not possess the correct replication metadata.
+Execution of CHANGE MASTER as per `mysql`.`slave_master_info` and  `mysql`.`slave_relay_log_info` table content is recommended.
+connection master;
+TRUNCATE TABLE `mysql`.`slave_master_info`;
+TRUNCATE TABLE `mysql`.`slave_relay_log_info`;
+********************************************************************
+* Test case2: Upgrade when repository tables are empty.            *
+* mysql_upgrade script should not report any warning.              *
+********************************************************************
+connection master;
+connection slave;
+"====== Clean up ======"
+connection master;
+DROP TABLE `mysql`.`slave_master_info`, `mysql`.`slave_relay_log_info`;
+include/rpl_end.inc

mysql-test/main/rpl_mysql_upgrade_slave_repo_check.test

+# ==== Purpose ====
+#
+# While upgrading from "mysql" to "mariadb" if slave info repositories are
+# configured to be tables then appropriate warnings should be reported.
+#
+# ==== Implementation ====
+#
+# Steps:
+#    1 - On MariaDB server create `mysql`.`slave_master_info` and
+#        `mysql.slave_relay_log_info` tables to simulate upgrade from "mysql"
+#        to "mariadb" server. Insert data into these tables.
+#    2 - Execute "mysql_upgrade" script and verify that appropriate warning
+#        is reported. i.e Warning is to alert user that the data present in
+#        repository tables will be ignored.
+#    3 - Truncate these tables. This simulates repositories being file and
+#        the tables are empty.
+#    4 - Execute "mysql_upgrade" script and verify that no warnings are
+#        reported.
+#
+# ==== References ====
+#
+# MDEV-10047: table-based master info repository
+#
+
+--source include/have_innodb.inc
+--source include/mysql_upgrade_preparation.inc
+--source include/have_binlog_format_mixed.inc
+--source include/master-slave.inc
+
+--write_file $MYSQLTEST_VARDIR/tmp/slave_table_repo_init.sql
+--disable_query_log
+--disable_result_log
+SET SQL_LOG_BIN=0;
+# Table structure extracted from MySQL-5.6.47
+CREATE TABLE `mysql`.`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 NOT NULL DEFAULT '' 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.',
+  PRIMARY KEY (`Host`,`Port`)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8 STATS_PERSISTENT=0 COMMENT='Master Information';
+
+INSERT INTO `mysql`.`slave_master_info` VALUES (23,'master-bin.000001', 120, 'localhost', 'root'," ", 13000, 60, 0," "," "," "," "," ",0 , 60," ", " ", '28e10fdd-6289-11ea-aab9-207918567a34',10," "," ", 0 );
+
+# Table structure extracted from MySQL-5.6.47
+CREATE TABLE `mysql`.`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.',
+  PRIMARY KEY (`Id`)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8 STATS_PERSISTENT=0 COMMENT='Relay Log Information';
+
+INSERT INTO `mysql`.`slave_relay_log_info` VALUES (7,'./slave-relay-bin.000001',4 ," ",0, 0 ,0 , 1);
+SET SQL_LOG_BIN=1;
+--enable_query_log
+--enable_result_log
+EOF
+
+--echo ********************************************************************
+--echo * Test case1: Upgrade when repository tables have data.            *
+--echo * mysql_upgrade script should report warnings.                     *
+--echo ********************************************************************
+--connection master
+--source $MYSQLTEST_VARDIR/tmp/slave_table_repo_init.sql
+--exec $MYSQL_UPGRADE --skip-verbose --force --user=root > $MYSQLTEST_VARDIR/log/mysql_upgrade_master.log 2>&1
+--cat_file $MYSQLTEST_VARDIR/log/mysql_upgrade_master.log
+
+--connection slave
+--source $MYSQLTEST_VARDIR/tmp/slave_table_repo_init.sql
+--exec $MYSQL_UPGRADE --skip-verbose --force --user=root > $MYSQLTEST_VARDIR/log/mysql_upgrade_slave.log 2>&1
+--cat_file $MYSQLTEST_VARDIR/log/mysql_upgrade_slave.log
+
+--connection master
+let $datadir= `select @@datadir`;
+remove_file $datadir/mysql_upgrade_info;
+TRUNCATE TABLE `mysql`.`slave_master_info`;
+TRUNCATE TABLE `mysql`.`slave_relay_log_info`;
+--remove_file $MYSQLTEST_VARDIR/log/mysql_upgrade_master.log
+--remove_file $MYSQLTEST_VARDIR/log/mysql_upgrade_slave.log
+
+--echo ********************************************************************
+--echo * Test case2: Upgrade when repository tables are empty.            *
+--echo * mysql_upgrade script should not report any warning.              *
+--echo ********************************************************************
+--connection master
+--exec $MYSQL_UPGRADE --skip-verbose --force --user=root > $MYSQLTEST_VARDIR/log/mysql_upgrade_master.log 2>&1
+--cat_file $MYSQLTEST_VARDIR/log/mysql_upgrade_master.log
+
+--connection slave
+--exec $MYSQL_UPGRADE --skip-verbose --force --user=root > $MYSQLTEST_VARDIR/log/mysql_upgrade_slave.log 2>&1
+--cat_file $MYSQLTEST_VARDIR/log/mysql_upgrade_slave.log
+
+--echo "====== Clean up ======"
+--connection master
+let $datadir= `select @@datadir`;
+remove_file $datadir/mysql_upgrade_info;
+DROP TABLE `mysql`.`slave_master_info`, `mysql`.`slave_relay_log_info`;
+
+--remove_file $MYSQLTEST_VARDIR/tmp/slave_table_repo_init.sql
+--remove_file $MYSQLTEST_VARDIR/log/mysql_upgrade_master.log
+--remove_file $MYSQLTEST_VARDIR/log/mysql_upgrade_slave.log
+
+--source include/rpl_end.inc