[#MDEV-9856] wsrep_gtid_mode requires nodes to have the same log

wsrep_gtid_mode currently requires nodes to have the same log_bin path for it to work. This path can be checked at run-time by looking at log_bin_basename. Is this intentional?

For example, let's say we have a 2-node cluster.

Node 1 has the following:

MariaDB [(none)]> SHOW GLOBAL VARIABLES LIKE 'gtid%pos';

+------------------+------------------------+

| Variable_name    | Value                  |

+------------------+------------------------+

| gtid_binlog_pos  | 0-1-5,1-1-63334,3-1-15 |

| gtid_current_pos | 0-1-5,1-1-63334,3-1-15 |

| gtid_slave_pos   |                        |

+------------------+------------------------+

3 rows in set (0.00 sec)

MariaDB [(none)]> SHOW GLOBAL VARIABLES LIKE 'log_bin_basename';

+------------------+----------------------------+

| Variable_name    | Value                      |

+------------------+----------------------------+

| log_bin_basename | /var/lib/mysql/mariadb-bin |

+------------------+----------------------------+

1 row in set (0.00 sec)

MariaDB [(none)]> SHOW GLOBAL VARIABLES LIKE 'wsrep_gtid%';

+----------------------+-------+

| Variable_name        | Value |

+----------------------+-------+

| wsrep_gtid_domain_id | 3     |

| wsrep_gtid_mode      | ON    |

+----------------------+-------+

2 rows in set (0.00 sec)

Let's say that I start up node 2 with a configuration with these parameters:

wsrep_gtid_mode=ON

wsrep_gtid_domain_id=3

log_bin=mariadb-bin

wsrep_sst_method=rsync

When it starts up, it looks good:

MariaDB [(none)]> SHOW GLOBAL VARIABLES LIKE 'gtid%pos';

+------------------+------------------------+

| Variable_name    | Value                  |

+------------------+------------------------+

| gtid_binlog_pos  | 0-1-5,1-1-63334,3-2-14 |

| gtid_current_pos | 3-2-14                 |

| gtid_slave_pos   |                        |

+------------------+------------------------+

3 rows in set (0.01 sec)

MariaDB [(none)]> SHOW GLOBAL VARIABLES LIKE 'log_bin_basename';

+------------------+----------------------------+

| Variable_name    | Value                      |

+------------------+----------------------------+

| log_bin_basename | /var/lib/mysql/mariadb-bin |

+------------------+----------------------------+

1 row in set (0.00 sec)

MariaDB [(none)]> SHOW GLOBAL VARIABLES LIKE 'wsrep_gtid%';

+----------------------+-------+

| Variable_name        | Value |

+----------------------+-------+

| wsrep_gtid_domain_id | 3     |

| wsrep_gtid_mode      | ON    |

+----------------------+-------+

2 rows in set (0.00 sec)

But what happens if we change log_bin and restart the server? It doesn't look so good:

MariaDB [(none)]> SHOW GLOBAL VARIABLES LIKE 'gtid%pos';

+------------------+-------+

| Variable_name    | Value |

+------------------+-------+

| gtid_binlog_pos  | 3-1-1 |

| gtid_current_pos |       |

| gtid_slave_pos   |       |

+------------------+-------+

3 rows in set (0.01 sec)

MariaDB [(none)]> SHOW GLOBAL VARIABLES LIKE 'log_bin_basename';

+------------------+-----------------------------+

| Variable_name    | Value                       |

+------------------+-----------------------------+

| log_bin_basename | /var/lib/mysql/mariadb-bin1 |

+------------------+-----------------------------+

1 row in set (0.00 sec)

MariaDB [(none)]> SHOW GLOBAL VARIABLES LIKE 'wsrep_gtid%';

+----------------------+-------+

| Variable_name        | Value |

+----------------------+-------+

| wsrep_gtid_domain_id | 3     |

| wsrep_gtid_mode      | ON    |

+----------------------+-------+

2 rows in set (0.00 sec)

[MDEV-9856] wsrep_gtid_mode requires nodes to have the same log_bin path Created: 2016-04-01 Updated: 2019-05-23 Resolved: 2019-05-23
Status:	Closed
Project:	MariaDB Server
Component/s:	Galera, Replication
Affects Version/s:	10.1.13
Fix Version/s:	N/A

[MDEV-9856] wsrep_gtid_mode requires nodes to have the same log_bin path Created: 2016-04-01 Updated: 2019-05-23 Resolved: 2019-05-23