While most of the talk recently has mostly been around the new changes in MySQL 5.6 (and that is understandable), I have had lately some very interesting cases to deal with, with respect to the Metadata Locking related changes that were introduced in MySQL 5.5.3. It appears that the implications of Metadata Locking have not [...]
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 [...]
Fun with the MySQL pager command
Last time I wrote about a few tips that can make you more efficient when using the command line on Unix. Today I want to focus more on pager. The most common usage of pager is to set it to a Unix pager such as less. It can be very useful to view the result [...]
Percona Toolkit by example – pt-stalk
pt-stalk recipes: Gather forensic data about MySQL when a server problem occurs It happens to us all from time to time: a server issue arises that leaves you scratching your head. That’s when Percona Toolkit’s pt-stalk comes into play, helping you diagnose the problem by capturing diagnostic data that helps you pinpoint what’s causing the [...]
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 [...]
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 [...]
Replaying database load with Percona Playback
If you are planning to upgrade or make any configuration change on your MySQL database the first advice usually is: – Benchmark! How should we do that benchmark? People usually run generic benchmark tools like sysbench, tpcc or mysqlslap that are good to know the number of transactions per seconds that a database can do [...]
Percona XtraDB Cluster reference architecture with HaProxy
This post is a step-by-step guide to set up Percona XtraDB Cluster (PXC) in a virtualized test sandbox. I used Amazon EC2 micro instances, but the content here is applicable for any kind of virtualization technology (for example VirtualBox). The goal is to give step by step instructions, so the setup process is understandable and [...]
Actively monitoring replication connectivity with MySQL’s heartbeat
Until MySQL 5.5 the only variable used to identify a network connectivity problem between Master and Slave was slave-net-timeout. This variable specifies the number of seconds to wait for more Binary Logs events from the master before abort the connection and establish it again. With a default value of 3600 this has been a historically [...]
Identifying the load with the help of pt-query-digest and Percona Server
Overview Profiling, analyzing and then fixing queries is likely the most oft-repeated part of a job of a DBA and one that keeps evolving, as new features are added to the application new queries pop up that need to be analyzed and fixed. And there are not too many tools out there that can make [...]

