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: Failure Scenarios with only 2 nodes
July 25, 2012 By 6 Comments
During the design period of a new cluster, it is always advised to have at least 3 nodes (this is the case with PXC but it’s also the same with PRM). But why and what are the risks ? The goal of having more than 2 nodes, in fact an odd number is recommended in [...]
Can we improve MySQL variable handling ?
February 18, 2012 By 8 Comments
MySQL Settings (also known as Server Variables) have interesting property. When you set variable in running server this change is not persisted in any way and server will be back to old value upon restart. MySQL also does not have option to re-read config file without restarting as some other software so approach to change [...]
Optimizing InnoDB for creating 30,000 tables (and nothing else)
December 22, 2011 By 5 Comments
Once upon a time, it would have been considered madness to even attempt to create 30,000 tables in InnoDB. That time is now a memory. We have customers with a lot more tables than a mere 30,000. There have historically been no tests for anything near this many tables in the MySQL test suite. So, [...]
kernel_mutex problem. Or double throughput with single variable
December 2, 2011 By 17 Comments
Problem with kernel_mutex in MySQL 5.1 and MySQL 5.5 is known: Bug report. In fact in MySQL 5.6 there are some fixes that suppose to provide a solution, but MySQL 5.6 yet has long way ahead before production, and it is also not clear if the problem is really fixed. Meantime the problem with kernel_mutex [...]
Fishing with dynamite, brought to you by the randgen and dbqp
November 16, 2011 By Leave a Comment
I tend to speak highly of the random query generator as a testing tool and thought I would share a story that shows how it can really shine. At our recent dev team meeting, we spent approximately 30 minutes of hack time to produce test cases for 3 rather hard to duplicate bugs. Of course, [...]
Looking for InnoDB/XtraDB hacker
October 25, 2011 By 3 Comments
We are happy to see that Percona Server/XtraDB and XtraBackup are raising popularity and to keep excitement we want to have more features and more performance fixes! If you are experienced software engineer and feel strong enough to hack InnoDB/XtraDB code we invite you to join our development team to work on the following (but [...]
Multiple MySQL instances on Fusion-io ioDrive
October 7, 2011 By 6 Comments
It is known that MySQL due internal limitations is not able to utilize all CPU and IO resources available on modern hardware. Idea is to run multiple instances of MySQL to gain better performance on Fusion-io ioDrive card. Full report is available in PDF
Dynamic row format for MEMORY tables
September 6, 2011 By 5 Comments
The latest Percona Server release has one new feature: now MEMORY tables can have BLOB and TEXT columns, and VARCHAR columns will not waste space due to implicit extension to CHAR.
MySQL performance on EC2/EBS versus RDS
August 4, 2011 By 11 Comments
A while ago I started a series of posts showing benchmark results on Amazon EC2 servers with RAID’ed EBS volumes and MySQL, versus RDS machines. For reasons that won’t add anything to this discussion, I got sidetracked, and then time passed, and I no longer think it’s a good idea to publish those blog posts [...]
