September 18, 2014

percona-millipede – Sub-second replication monitor

I recently helped a client implement a custom replication delay monitor and wanted to share the experience and discuss some of the iterations and decisions that were made. percona-millipede was developed in conjunction with Vimeo with the following high-level goal in mind: implement a millisecond level replication delay monitor and graph the results.  Please visit […]

Seconds_Behind_Master fluctuating wildly? Check for events caught in a loop

Recently I was working with a customer where we noticed that Seconds_Behind_Master fluctuating from an expected value of 0 seconds behind to a fairly high six figure value.  The servers were configured in a master-master relationship and used 5 figure server_id values, and we had just migrated this cluster from one data centre to another […]

Percona Server 5.6.12-60.4 second Release Candidate now available

Percona is glad to announce the second Release Candidate release of Percona Server 5.6.12-60.4 on June 27th, 2013 (Downloads are available here and from the Percona Software Repositories). Based on the recently released MySQL 5.6.12, including all the bug fixes in it, Percona Server 5.6.12-60.4 is the second RC release in the Percona Server 5.6 series. […]

Configuring MySQL For High Number of Connections per Second

One thing I noticed during the observation was that there were roughly 2,000 new connections to MySQL per second during peak times. This is a high number by any account. When a new connection to MySQL is made, it can go into the back_log, which effectively serves as a queue for new connections on operating […]

Should we give a MySQL Query Cache a second chance ?

Over last few years I’ve been suggesting more people to disable Query Cache than to enable it. It can cause contention problems as well as stalls and due to coarse invalidation is not as efficient as it could be. These are however mostly due to neglect Query Cache received over almost 10 years, with very […]

MySQL Meetup in Charlotte,NC second attempt

I was going to visit Charlotte,NC and talk on MySQL Meetup in January but weather did not cooperate. I’m trying again and I hope this time I’m more lucky. As such I’m speaking on MySQL Meetup in Charlotte,NC 8th of February. If you’re interested in Scaling applications which use MySQL you will enjoy the talk […]

How we work on High Performance MySQL Second Edition

Baron have been updating you a lot about chapter by chapter progress so I should not repeat it, instead I thought it would be a good idea to write a bit about how we work on the book. Generally, quite similar to the previous book this is long process, which is probably what happens when […]

Working on “High Performance MySQL, Second Edition”, how you can help?

As you may already have seen announcement by Baron we’re working on major rewrite of High Performance MySQL book – the most famous book about MySQL Performance on the market… which is getting old though. We’ve been slowly working on the book for over half a year now and were later joined by Arjen Lentz […]

Guess what?! Microsecond slow query timing finally available in MySQL!

Vadim asked me yesterday to update Microslow patch for 5.1.21, because the previous one I wrote for 5.1.20 failed to apply correctly on the new MySQL release. Imagine the expression on my face after I unpacked the sources and found out that MySQL incorporated the patch to their release. So it’s a built-in feature now […]

Innodb Second Start prevention bug ?

I filed the following bug today. Basically it looks like in certain conditions Innodb may be started twice in the parallel on the same data files which can hurt database badly. It is true it does not seems to be 100% repeatable but I’ve seen it multiple times in different environments. I’m not sure if […]