Jean-François Gagné

Have you ever needed to get some additional write throughput from MySQL ? If yes, you probably found that setting sync_binlog to 0 (and trx_commit to 2) gives you an extra performance boost. As all such easy optimisation, it comes at a cost. This talk explains how this tuning works, presents its consequences and makes recommendations to avoid them. This will bring us to the details of how MySQL commits transactions and how those are replicated to slaves. Come to this talk to learn how to get the benefit of this tuning the right way and to learn some replication internals.

You’ve deployed automation, enabled automatic master failover and tested it many times: great, you can now sleep at night without being paged by a failing server. However, when you wake up in the morning, things might not have gone the way you expect. This talk will be about such a surprise.

Once upon a time, a failure brought down a master. Automation kicked in and fixed things. However, a fancy failure, combined with human errors, with an edge-case recovery, and a lack of oversight in automation, lead to a split-brain. This talk will go into details about the convoluted - but still real world - sequence of events that lead to this disaster. I will cover what could have avoided the split-brain and what could have make things easier to fix it.

I will discuss MySQL and MariaDB parallel replication implementation, including their strengths, weaknesses and tuning parameters. I will also present benchmark results from real Booking.com workloads.

In the last 24 months, MySQL replication speed has improved a lot thanks to implementing parallel replication. MySQL and MariaDB have different types of parallel replication; in this talk, I present in detail the different implementations, with their limitations and the corresponding tuning parameters (covering MySQL 5.6, MariaDB 10.0, MariaDB 10.1 and MySQL 5.7). I also present benchmark results from real Booking.com workloads. Finally, I discuss some deployments at Booking.com that benefits from parallel replication speed improvements.