There are many reasons for wanting a small MySQL database server: You’re a uni student who wants to learn the SQL language better and needs a mini-testbox You’re a Windows user who wants to play around with Percona Server on Linux You’re a corporate application developer who wants a small SQL development & test box [...]
Percona Server on the Raspberry Pi: Your own MySQL Database Server for Under $80
February 25, 2013 By 10 Comments
Can’t Create Thread: Errno 11 (A Tale of Two Ulimits)
February 4, 2013 By 10 Comments
Recently some of my fellow Perconians and I have noticed a bit of an uptick in customer cases featuring the following error message:
1 2 | SQLSTATE[HY000] [1135] Can't create a new thread (errno 11); if you are not out of available memory, you can consult the manual for a possible OS-dependent bug. |
The canonical solution to this issue, if you do a bit of Googling, is to increase the number of processes / threads available to the MySQL user, typically by adding a [...]
Implications of Metadata Locking Changes in MySQL 5.5
February 1, 2013 By 9 Comments
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
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 [...]
Fun with the MySQL pager command
January 21, 2013 By 6 Comments
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
January 3, 2013 By 3 Comments
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
November 26, 2012 By 4 Comments
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 [...]
Filling the tmp partition with persistent connections
August 6, 2012 By 14 Comments
The use of tmpfs/ramfs as /tmp partition is a common trick to improve the performance of on-disk temporary tables. Servers usually have less RAM than disk space so those kind of partitions are very limited in size and there are some cases were we can run out of space. Let’s see one example. We’re running [...]
Percona XtraDB Cluster reference architecture with HaProxy
June 20, 2012 By 63 Comments
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 [...]
Benchmarking single-row insert performance on Amazon EC2
May 16, 2012 By 17 Comments
I have been working for a customer benchmarking insert performance on Amazon EC2, and I have some interesting results that I wanted to share. I used a nice and effective tool iiBench which has been developed by Tokutek. Though the “1 billion row insert challenge” for which this tool was originally built is long over, [...]
