Option to allow setting the binlog_format with Galera

Hi,

I know this is like a bit going backwards but to check consistency between:

• nodes of (same) galera cluster
• async slave of galera cluster

We need to set the binlog_format to STATEMENT (using a tool such as Percona pt-table-checksum by example).
This is also valid for other tools (such as pt-table-sync).

In https://mariadb.atlassian.net/browse/MDEV-6924 we have completely disallowed the change of the binlog_format, when wsrep_on = ON.

You can use a workaround, setting wsrep_on = off and run the pt-table-checksum, but this works only for asynchronous slaves. Also, this is dangerous if one user drops the created table, without setting wsrep_on = off (I need to test this, blog post in progress)

Rogue applications (or users, or bugs) may compromise data consistency between nodes of the same cluster, or between master (cluster/standalone) and async slaves(cluster/standalone) and this is the only way I see today to check the consistency.

Could this be set as a parameter, such as wsrep_allow_unsafe_binlog_format ?

Changing the binlog_format is still allowed in latest PXC, and it seems we are taking our own road here.

Joffrey