Hi,

We have a MariaDB 10.3 replication setup with one master and a few chained slaves (each has log_slave_updates switched on). Master uses mainly MyISAM tables, slaves have about 10 or 40 threads for parallel replication.

Interesting is, that the first slave in the chain counts replicated statements into Non-Transactional Groups and the following ones count them into Transactional Groups.

Also, when checking process lists it seems that just one statement is being processed at the time (of the many threads) on the first slave, while there are multiple slave replication statements being executed on the 2nd and following slaves.

Please, does anyone know the reason why the replicated statements are counted into different groups? Or, more importantly, how to increase the parallelism on the first slave in the chain?

Thank you for any help.

Jan