The binlogs cache has been split into two versions, which are as follows:

Both caches can be tuned, and their usage depends on the engine you're using. For example, InnoDB/XtraDB are transactional engines, while MyISAM is a nontransactional engine. There is, of course, no sense in tuning a transactional cache if you're only using the MyISAM engine, and vice versa. By the way, the transactional cache shouldn't move if you're not using it.

Binlogs are mandatory for replication systems. If the cache is not correctly used, the disk will be used and slowdowns are felt. So, the first thing to do is to check the correct usage of that cache.

MariaDB [(none)]> show global status like 'Binlog_cache%';
+-----------------------+-------+
| Variable_name         | Value |
+-----------------------+-------+
| Binlog_cache_disk_use...