April 17, 2014

Handling long-running queries in MySQL with Percona XtraBackup

I recently had a case where replication lag on a slave was caused by a backup script. First reaction was to incriminate the additional pressure on the disks, but it turned out to be more subtle: Percona XtraBackup was not able to execute FLUSH TABLES WITH READ LOCK due to a long-running query, and the […]

My Percona Live UK 2013 Tutorial: MySQL DBA In A Nutshell! Hands On!

Do you want to get more familiar on how to become a MySQL DBA? Are you a developer familiar with writing applications that use MySQL but you feel a bit limited on how to  manage a MySQL Database? I would like to invite you in my tutorial ‘MySQL DBA In A Nutshell! Hands On! ‘ at Percona […]

MySQL 5.7 multi-source replication

Recently Oracle announced several new features for the latest available development version of MySQL that is 5.7.2 at the time of writing this article. Most of them are performance and replication related that show us how incredible the new release will be. In this post I’m going to try to explain in some easy steps […]

5 reasons why MySQL replication lag is flapping between 0 and XXXXX

Working day to day with Percona Remote DBA customers, we have been facing an issue from time to time when MySQL replication lag is flapping between 0 and XXXXX constantly – i.e. Seconds_Behind_Master is 0 for a few secs, then it’s like 6287 or 25341, again 0 and so on. I would like to note […]

Enabling crash-safe slaves with MySQL 5.6

Being able to configure slaves to be crash-safe is one of the major improvements of MySQL 5.6 with regards to replication. However we noticed confusion on how to enable this feature correctly, so let’s clarify how it should be done. In short 1. Stop MySQL on slave 2. Add relay_log_info_repository = TABLE and relay_log_recovery = […]

Crash-resistant replication: How to avoid MySQL replication errors

Percona Server’s “crash-resistant replication” feature is useful in versions 5.1 through 5.5. However, in Percona Server 5.6 it’s replaced with Oracle MySQL 5.6′s “crash safe replication” feature, which has it’s own implementation (you can read more about it here). A MySQL slave normally stores its position in files master.info and relay-log.info which are updated by […]

Schema changes – what’s new in MySQL 5.6?

Among many of the improvements you can enjoy in MySQL 5.6, there is one that addresses a huge operational problem that most DBAs and System Administrators encounter in their life: schema changes. While it is usually not a problem for small tables or those in early stages of product life cycle, schema changes become a […]

Changing an async slave of a PXC cluster to a new Master

Async and PXC A common question I get about Percona XtraDB Cluster is if you can mix it with asynchronous replication, and the answer is yes!  You can pick any node in your cluster and it can either be either a slave or a master just like any other regular MySQL standalone server (Just be […]

Choosing a MySQL HA Solution – Post-Webinar Q&A

Thanks to everyone who was in attendance on 05 June 2013 for my “Choosing a MySQL HA Solution” webinar. If you weren’t able to make it but are interested in listening to the presentation, it’s currently up and available for viewing over at percona.com. My apologies if we weren’t able to get to your question […]

Replication in MySQL 5.6: GTIDs benefits and limitations – Part 2

The main benefit of using GTIDs is to have much easier failover than with file-based replication. We will see how to change the replication topology when using GTID-based replication. That will show where GTIDs shine and where improvements are expected. This is the second post of a series of articles focused on MySQL 5.6 GTIDs. […]