September 14, 2014

MySQL 101: Monitor Disk I/O with pt-diskstats

Here on the Percona Support team we often ask customers to retrieve disk stats to monitor disk IO and to measure block devices iops and latency. There are a number of tools available to monitor IO on Linux. iostat is one of the popular tools and Percona Toolkit, which is free, contains the pt-diskstats tool […]

Why TokuDB hates Transparent HugePages

If you try to install the TokuDB storage engine on a modern Linux distribution it might fail with following error message: 2014-07-17 19:02:55 13865 [ERROR] TokuDB will not run with transparent huge pages enabled. 2014-07-17 19:02:55 13865 [ERROR] Please disable them to continue. 2014-07-17 19:02:55 13865 [ERROR] (echo never > /sys/kernel/mm/transparent_hugepage/enabled) You might be curious […]

Using MySQL 5.6 Performance Schema in multi-tenant environments

Hosting a shared MySQL instance for your internal or external clients (“multi-tenant”) was always a challenge. Multi-tenants approach or a “schema-per-customer” approach is pretty common nowadays to host multiple clients on the same MySQL sever. One of issues of this approach, however, is the lack of visibility: it is hard to tell how many resources (queries, disk, […]

Before every release: A glimpse into Percona XtraDB Cluster CI testing

I spoke last month at linux.conf.au 2014 in Perth, Australia, and one of my sessions focused on the “Continuous Integration (CI) testing of Percona XtraDB Cluster (PXC)” at the Developer,Testing, Release and CI miniconf. Here is the video of the presentation: Here is the presentation itself: Percona XtraDB Cluster before every release: Glimpse into CI […]

PERFORMANCE_SCHEMA vs Slow Query Log

A couple of weeks ago, shortly after Vadim wrote about Percona Cloud Tools and using Slow Query Log to capture the data, Mark Leith asked why don’t we just use Performance Schema instead? This is an interesting question and I think it deserves its own blog post to talk about. First, I would say main […]

Followup questions to ‘What’s new in Percona XtraDB Cluster 5.6′ webinar

Thanks to all who attended my webinar yesterday.  The slides and recording are available on the webinar’s page.  I was a bit overwhelmed with the amount of questions that came in and I’ll try to answer them the best I can here. Q: Does Percona XtraDB Cluster support writing to multiple master? Yes, it does.  However, […]

Percona Server: Thread Pool Improvements for Transactional Workloads

In a previous thread pool post, I mentioned that in Percona Server we used an open source implementation of MariaDB’s thread pool, and enhanced/improved it further. Below I would like to describe some of these improvements for transactional workloads. When we were evaluating MariaDB’s thread pool implementation, we observed that it improves scalability for AUTOCOMMIT […]

Percona Server: Improve Scalability with Percona Thread Pool

By default, for every client connection the MySQL server spawns a separate thread which will process all statements for this connection. This is the ‘one-thread-per-connection’ model. It’s simple and efficient until some number of connections N is reached. After this point performance of the MySQL server will degrade, mostly due to various contentions caused by […]

Linux performance tuning tips for MySQL

Because most MySQL production systems probably run on Linux, I’ve decided to place the most important Linux tuning tips that will help improve MySQL performance. There is nothing new here, most of them are well known, however, I’ve decided to collect those Linux configuration tips into 1 blog post. Filesystem ext4 (or xfs), mount with […]

Percona XtraDB Cluster: Setting up a simple cluster

Percona XtraDB Cluster (PXC) is different enough from async replication that it can be a bit of a puzzle how to do things the Galera way.  This post will attempt to illustrate the basics of setting up 2 node PXC cluster from scratch. Requirements Two servers (could be VMs) that can talk to each other. […]