April 20, 2014

Galera Flow Control in Percona XtraDB Cluster for MySQL

Last week at Percona Live, I delivered a six-hour tutorial about Percona XtraDB Cluster (PXC) for MySQL.  I actually had more material than I covered (by design), but one thing I regret we didn’t cover was Flow control.  So, I thought I’d write a post covering flow control because it is important to understand. What […]

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 […]

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 […]

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 […]

Comparing Percona XtraDB Cluster with Semi-Sync replication Cross-WAN

I have a customer who is considering Percona XtraDB Cluster (PXC) in a two colo WAN environment.  They wanted me to do a test comparing PXC against semi-synchronous replication to see how they stack up against each other. Test Environment The test environment included AWS EC2 nodes in US-East and US-West (Oregon).  The ping RTT latency […]

Percona Server 5.5.15 + Galera 21.1-beta2

Codership team published beta2 of MySQL 5.5.15 with Galera replication https://launchpad.net/codership-mysql and we made port to Percona Server: source code: lp:~percona-dev/percona-server/percona-server-galera-5.5.15 binaries for RedHat/CentOS 6: http://www.percona.com/downloads/TESTING/Galera/Percona-XtraDB-Galera-5.5.15.tar.gz What difference between Percona Server+Galera and MySQL 5.5.15 ? First of course, Percona Server+Galera is based on our XtraDB engine. Second, we provide wsrep_sst_xtrabackup script, which allows to use […]

Percona Server 5.1.57 with Galera 0.8.1

Codership team announced availability of MySQL/Galera 0.8.1, which is minor release, but actually it has bunch of improvements that makes Galera replication more user friendly (there are many bugs fixed, reported by me personally, what annoyed me a lot). As part of my evaluation activity I ported MySQL/Galera 0.8.1 to Percona Server/Galera 0.8.1 and you […]

Product to try: MySQL/MariaDB-Galera 0.8

I wrote about Galera about 1.5 years ago: State of the art: Galera – synchronous replication for InnoDB. It was about the 0.7 release, which was more like a proof-of-concept release (though Galera’s developers may not agree with that ) with some serious limitations (like using mysqldump for node propagation). The Galera team heard my […]

Percona Live MySQL Conference and Expo 2014: Things I’m looking forward to

The Percona Live MySQL Conference and Expo 2014 is just two months away. I’m very excited about this year’s event which continues our tradition of open technical discussions and inviting all parties to the table. We have a great amount of technical talks from Oracle – I’m especially excited about future-focused talks shedding some light […]