I talk with lot of people who are really interested in Percona XtraDB Cluster (PXC) and mostly they are interested in PXC as a high-availability solution. But, what they tend not to think too much about is if moving from async to synchronous replication is right for their application or not. Facts about Galera replication [...]
Follow these basics when migrating to Percona XtraDB Cluster for MySQL
Galera/Percona XtraDB Cluster (PXC) for MySQL is a hot thing right now and some users jump right in without enough testing. Consequently, they’re more likely to either suffer failure or issues that prevent them from moving forward. If you are thinking of migrating your workload to Percona XtraDB Cluster, make sure to go through these [...]
Investigating MySQL Replication Latency in Percona XtraDB Cluster
I was curious to check how Percona XtraDB Cluster behaves when it comes to MySQL replication latency — or better yet, call it data propagation latency. It was interesting to see whenever I can get stale data reads from other cluster nodes after write performed to some specific node. To test it I wrote quite a [...]
Read/Write Splitting with PHP Webinar Questions Followup
Today I gave a presentation on “Read/Write Splitting with PHP” for Percona Webinars. If you missed it, you can still register to view the recording and my slides. Thanks to everyone who attended, and especially to folks who asked the great questions. I answered as many as I could during the session, but here are [...]
Percona and the MariaDB Foundation
There have been several reports (1,2,3) describing Percona’s stance regarding the MariaDB Foundation that are not totally accurate so I though it would be worth it to describe where we stand on this and related matters. First, let me say the creation of theMariaDB Foundation is a good thing for the MariaDB Community and I’m [...]
Realtime stats to pay attention to in Percona XtraDB Cluster and Galera
I learn more and more about Galera every day. As I learn more, I try to keep my myq_gadgets toolkit up to date with what I consider is important to keep any eye on on a PXC node. In that spirit, I just today pushed some changes to the ‘wsrep’ report, and I thought I’d go over [...]
Understanding Multi-node writing conflict metrics in Percona XtraDB Cluster and Galera
I have addressed previously how multi-node writing causes unexpected deadlocks in PXC, at least, it is unexpected unless you know how Galera replication works. This is a complicated topic and I personally feel like I’m only just starting to wrap my head around it. The magic of Galera replication The short of it is that Galera [...]
Percona XtraDB Cluster – installation and setup webinar follow up Q&A
Thanks for all, who attended my webinar, I got many questions and I wanted to take this opportunity to answer them. Q: Even ntp has a delay of 0.3-0.4 between servers does that mean a 0.25 as from logs can be an issue ? A: My demo vms were running for a few hours before [...]
Automation: A case for synchronous replication
Just yesterday I wrote about math of automatic failover today I’ll share my thoughts about what makes MySQL failover different from many other components and why asynchronous nature of standard replication solution is causing problems with it. Lets first think about properties of simple components we fail over – web servers, application servers etc. We [...]
MySQL Indexing Best Practices: Webinar Questions Followup
I had a lot of questions on my MySQL Indexing: Best Practices Webinar (both recording and slides are available now) We had lots of questions. I did not have time to answer some and others are better answered in writing anyway. Q: One developer on our team wants to replace longish (25-30) indexed varchars with [...]

