Preparing for my talk for Percona MySQL University in Raleigh,NC, Tuesday 29th of January I have created the outline of improvements available in MySQL 5.6 which I thought was worth sharing to give a feel for how massive work have been done for this release in variety of areas. I’m sure the list is not [...]
Read/Write Splitting with PHP Webinar Questions Followup
January 23, 2013 By 4 Comments
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 [...]
Common MySQL traps webinar questions followup
January 17, 2013 By 1 Comment
Thanks to all attendees of the webinar yesterday! If you missed it, you can watch the video recording. Here are some questions that remained unanswered due to time constraints. Q: Are there any technical considerations or best practice tips to have a replicated slave in the cloud, for example on Amazon AWS? Hardware resources are [...]
Profiling MySQL Memory Usage With Valgrind Massif
January 9, 2013 By 1 Comment
There are times where you need to know exactly how much memory the mysqld server (or any other program) is using, where (i.e. for what function) it was allocated, how it got there (a backtrace, please!), and at what point in time the allocation happened. For example; you may have noticed a sharp memory increase [...]
How does MySQL Replication really work?
January 9, 2013 By 9 Comments
While we do have many blog posts on replication on our blog, such as on replication being single-threaded, on semi-synchronous replication or on estimating replication capacity, I don’t think we have one that covers the very basics of how MySQL replication really works on the high level. Or it’s been so long ago I can’t [...]
Percona XtraDB Cluster (PXC): what about GRA_*.log files ?
December 19, 2012 By Leave a Comment
How easy is it to identify and debug Percona XtraDB Cluster replication problem ? If you are using PXC, you may have already seen in your datadirectory several log files starting with GRA_ Those files correspond to a replication failure. That means the slave thread was not able to apply one transaction. For each of [...]
Quickly finding unused indexes (and estimating their size)
December 5, 2012 By 2 Comments
I had a customer recently who needed to reduce their database size on disk quickly without a lot of messy schema redesign and application recoding. They didn’t want to drop any actual data, and their index usage was fairly high, so we decided to look for unused indexes that could be removed. Collecting data It’s [...]
Percona Toolkit version 2.1.6 released
November 15, 2012 By 3 Comments
The Percona Toolkit team is happy to announce the release of Percona Toolkit version 2.1.6. This is the sixth stable release in the 2.1 series, and primarily a bug-fix release; We suggest that users upgrade to the latest version of the tools. The complete list of changes is on the Launchpad milestone for 2.1.6, but [...]
Percona XtraDB Cluster – installation and setup webinar follow up Q&A
October 28, 2012 By 4 Comments
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 [...]
Using pt-table-checksum with Percona XtraDB Cluster
October 15, 2012 By 2 Comments
As of Percona Toolkit v2.1.5, pt-table-checksum works correctly with Percona XtraDB Cluster, but it doesn’t work quite like a traditional replication setup because cluster nodes are not like traditional replicas. In this post I demonstrate how to use pt-table-checksum with Percona XtraDB Cluster. First, you’ll need Percona Toolkit v2.1.5 or newer and Percona XtraDB Cluster 5.5.27-23.6 [...]
