Warning
Error Code:
1738
MariaDB Error 1738: Binlog Cache Size Mismatch
Description
This error occurs when the configured `binlog_cache_size` variable is set to a value larger than `max_binlog_cache_size`. MariaDB automatically adjusts `binlog_cache_size` down to match `max_binlog_cache_size` to ensure operational stability, but it indicates a configuration inconsistency.
Error Message
Option binlog_cache_size (%lu) is greater than max_binlog_cache_size (%lu); setting binlog_cache_size equal to max_binlog_cache_size.
Known Causes
3 known causesIncorrect Manual Configuration
A user or administrator manually set `binlog_cache_size` to a value higher than `max_binlog_cache_size` in the MariaDB configuration file (`my.cnf` or `my.ini`).
Dynamic Variable Update Mismatch
`binlog_cache_size` was dynamically changed at runtime using `SET GLOBAL` to a value that exceeds the current `max_binlog_cache_size`.
Reduced Max Cache Size
`max_binlog_cache_size` was reduced after `binlog_cache_size` had already been set to a higher value, creating a new conflict.
Solutions
3 solutions available1. Adjust binlog_cache_size Directly easy
Manually set binlog_cache_size to a valid value within the allowed limit.
1
Connect to your MariaDB server.
2
Check the current values of `binlog_cache_size` and `max_binlog_cache_size`.
SHOW VARIABLES LIKE 'binlog%';3
If `binlog_cache_size` is indeed greater than `max_binlog_cache_size`, you can either increase `max_binlog_cache_size` (if your system resources allow and it's not already at a practical maximum) or decrease `binlog_cache_size` to be equal to or less than `max_binlog_cache_size`. For a quick fix, setting it to `max_binlog_cache_size` is often sufficient.
SET GLOBAL binlog_cache_size = <new_value>; -- Replace <new_value> with the value of max_binlog_cache_size or a smaller value.4
To make this change permanent across server restarts, edit your MariaDB configuration file (e.g., `my.cnf` or `my.ini`). Locate the `[mysqld]` section and add or modify the `binlog_cache_size` line.
[mysqld]
binlog_cache_size = <new_value>5
Restart the MariaDB service for the configuration file changes to take effect.
2. Increase max_binlog_cache_size medium
Allow a larger binlog cache by increasing max_binlog_cache_size.
1
Connect to your MariaDB server.
2
Check the current values of `binlog_cache_size` and `max_binlog_cache_size`.
SHOW VARIABLES LIKE 'binlog%';3
If `max_binlog_cache_size` is too restrictive and your system has ample RAM, you can increase it. This will allow `binlog_cache_size` to be set to a larger value if needed.
SET GLOBAL max_binlog_cache_size = <new_larger_value>; -- Choose a value that is appropriate for your system's memory and workload.4
To make this change permanent across server restarts, edit your MariaDB configuration file (e.g., `my.cnf` or `my.ini`). Locate the `[mysqld]` section and add or modify the `max_binlog_cache_size` line.
[mysqld]
max_binlog_cache_size = <new_larger_value>5
Restart the MariaDB service for the configuration file changes to take effect.
3. Review and Optimize Transactions advanced
Reduce the need for large binlog caches by optimizing application transactions.
1
Analyze your application's transaction patterns. Identify long-running or very large transactions that might be contributing to the high binlog cache usage.
2
Break down large transactions into smaller, more manageable ones. This can reduce the amount of data that needs to be buffered in the binlog cache at any given time.
3
Ensure that your application is not performing unnecessary read operations within transactions that are primarily for writing data.
4
Consider using `COMMIT` more frequently within your application logic, especially if you have loops that perform many individual updates.
5
Monitor the `Binlog_cache_use` and `Binlog_cache_disk_use` status variables to understand if transactions are frequently spilling to disk, which indicates a need for larger caches or transaction optimization.
SHOW GLOBAL STATUS LIKE 'Binlog%';