0

I am trying to set up MySQL group replication. Only problem is, that when I try to start replication group, It starts with super_read_only.

Here the configurations in my.cnf file

[mysqld]

max_binlog_size = 4096
default_authentication_plugin     = mysql_native_password

log_bin                           = mysql-bin-1.log
enforce_gtid_consistency          = ON
gtid_mode                         = ON
log_slave_updates                 = ON
binlog_checksum                   = NONE

plugin-load-add                   = group_replication.so
plugin-load-add                   = mysql_clone.so
relay_log_recovery                = ON
transaction_write_set_extraction  = XXHASH64
loose_group_replication_start_on_boot                    = OFF
loose_group_replication_group_name                       = 74fe8890-679f-4e93-9169-a7edfbc1d427
loose_group_replication_group_seeds                      = mysql_cluster_mysql0_1:3306, mysql_cluster_mysql1_1:3306, mysql_cluster_mysql2_1:3306
loose_group_replication_single_primary_mode              = ON
loose_group_replication_enforce_update_everywhere_checks = OFF
bind-address = 0.0.0.0

instances are run inside docker, that's why group seed addresses has these hostnames.

Also here the procedure for running master instance.

DELIMITER $$

USE `db`$$

DROP PROCEDURE IF EXISTS `set_as_master`$$

CREATE DEFINER=`root`@`%` PROCEDURE `set_as_master`()
BEGIN
  SET @@GLOBAL.group_replication_bootstrap_group=1;
  CREATE USER IF NOT EXISTS 'repl'@'%';
  GRANT REPLICATION SLAVE ON *.* TO repl@'%';
  FLUSH PRIVILEGES;
  CHANGE MASTER TO MASTER_USER='root' FOR CHANNEL 'group_replication_recovery';
  START GROUP_REPLICATION;
  -- SELECT * FROM performance_schema.replication_group_members;
END$$

DELIMITER;

After running CALL start_as_master; in Sqlyog, process stucks on below lines.

'CHANGE MASTER TO FOR CHANNEL 'group_replication_recovery' executed'. Previous state master_host='', master_port= 3306, master_log_file='', master_log_pos= 4, master_bind=''. New state master_host='', master_port= 3306, master_log_file='', master_log_pos= 4, master_bind=''.

2021-03-03T21:47:55.934818Z 8 [System] [MY-013587] [Repl] Plugin group_replication reported: 'Plugin 'group_replication' is starting.'

2021-03-03T21:47:55.935929Z 9 [System] [MY-011565] [Repl] Plugin group_replication reported: 'Setting super_read_only=ON.'

Why does it run with super_read_only=ON? Is there anything I miss during configuration or running script?

MySQL version is 8.0.23.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.