I'm experiencing some replication issues. I have a Master-Slave replication with mysql; the slave had binlog-format = ROW, Last sunday (3 days ago) I changed the format to MIXED (this is master too; so I expected better performance for his slave). The thing is, it appeared to work fine sunday and monday; but starting tuesday this slave began to lag and kept falling behind for some hours... It catched up around midnight, and today again from nowhere started to lag and kept behind many hours again; trying to understand what's happening I've been asking around and it seems like the workload is the same like past weeks, nothing new that could be causing this behavior. I noticed that the Disk Usage has incremented considerably lately, which is strange, I thought that this change would cause less disk writes...
I'm attaching the graphic, you can see a lot of reads december 18, that was some Cold Backup, so it's not that.... The question is: Could the change of binlog-format be the cause of this behavior? Is it normal that it is writing a lot more to disk? And is there a way to improve this?
Server1's slave binlog_format=MIXED (This is the one changed, and where the I/O is up).