[#MDEV-10903] Strangeness with binlog_cache

I am seeing strage behavior with binlog_cache_size when trying to set it too large in the my.cnf file.

The behavior is similar to the bug regarding max_binlog_stmt_cache_size reported here:

https://jira.mariadb.org/browse/MDEV-4774

If you attempt to set binlog_cache_size to 18446744073709547520 via the my.cnf file, the max value per the manual, then your instance will not start, even though this can be set dynamically.

Set the following:

[mysqld]

binlog_cache_size=18446744073709547520

On Windows, the instance will not start, and nothing is logged.

On Linux, it also will not start, but at least you will see an error message similar to the following:

160922 11:45:45 [ERROR] Incorrect integer value: '18446744073709547520'

160922 11:45:45 [Warning] option 'binlog_cache_size': unsigned value 0 adjusted to 4096

160922 11:45:45 [ERROR] /rdsdbbin/mysql/bin/mysqld: Error while setting value '18446744073709547520' to 'binlog_cache_size'

160922 11:45:45 [ERROR] Aborting

As stated, this variable can be set dynamically:

mysql> select @@binlog_cache_size, @@version;

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

| @@binlog_cache_size | @@version       |

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

|               32768 | 10.1.16-MariaDB |

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

1 row in set (0.00 sec)

mysql> select @@global.binlog_cache_size, @@version;

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

| @@global.binlog_cache_size | @@version       |

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

|                      32768 | 10.1.16-MariaDB |

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

1 row in set (0.00 sec)

mysql> set @@global.binlog_cache_size=18446744073709547520;

Query OK, 0 rows affected (0.00 sec)

mysql> select @@global.binlog_cache_size, @@version;

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

| @@global.binlog_cache_size | @@version       |

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

|       18446744073709547520 | 10.1.16-MariaDB |

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

1 row in set (0.00 sec)

[MDEV-10903] Strangeness with binlog_cache_size Settings Created: 2016-09-26 Updated: 2019-04-03 Resolved: 2019-04-03
Status:	Closed
Project:	MariaDB Server
Component/s:	OTHER
Affects Version/s:	5.5, 10.0, 10.1
Fix Version/s:	10.0.30, 10.1.22

[MDEV-10903] Strangeness with binlog_cache_size Settings Created: 2016-09-26 Updated: 2019-04-03 Resolved: 2019-04-03