Hi,
I am having an issue with MariaDB semi-sync replication.
Setting up replication between master and slaves works as expected but when the master begins writing to a new binlog file replication stalls on waiting for an ack from the semi-sync slave.
I have the fallback to async set very high because I basically don't want the server to ever commit writes to the master that aren't committed to the slave.
I have discussed this somewhat on the mailing list and have created this gist which reliably reproduces the issue: https://gist.github.com/josephglanville/c9a69b02de319ee06aef1a8d787bcce3
It's possible this is a configuration issue rather than a bug, config for master and slave is generated in the scripts in the gist so if that is the case hopefully it's an easy fix.
Joseph.
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Bug
Major
Switching to AFTER_COMMIT works around the problem but doesn't accomplish loss-less replication.
Discussion on the mailing list indicates this is likely a race updating MYSQL_BIN_LOG::log_file_name as the after_sync callback is called with the new file name but the last offset of the previous binlog file.