September 18, 2014

Semi-Sync replication performance in MySQL 5.7.4 DMR

I was interested to hear about semi-sync replication improvements in MySQL’s 5.7.4 DMR release and decided to check it out.  I previously blogged about poor semi-sync performance and was pretty disappointed from semi-sync’s performance across WAN distances back then, particularly with many client threads. The Test The basic environment of these tests was: AWS EC2 […]

OOM relation to vm.swappiness=0 in new kernel

I have recently been involved in diagnosing the reasons behind OOM invocation that would kill the MySQL server process. Of course these servers were primarily running MySQL. As such the MySQL server process was the one with the largest amount of memory allocated. But the strange thing was that in all the cases, there was […]

Tools and tips for analysis of MySQL’s Slow Query Log

MySQL has a nice feature, slow query log, which allows you to log all queries that exceed a predefined about of time to execute. Peter Zaitsev first wrote about this back in 2006 – there have been a few other posts here on the MySQL Performance Blog since then (check this and this, too) but […]

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 […]

The ARCHIVE Storage Engine – does it do what you expect?

Sometimes there is a need for keeping large amounts of old, rarely used data without investing too much on expensive storage. Very often such data doesn’t need to be updated anymore, or the intent is to leave it untouched. I sometimes wonder what I should really suggest to our Support customers. For this purpose, the […]

2 cases for MySQL server overload

Your MySQL server is overloaded. You see hundreds of running queries in the SHOW PROCESSLIST taking many seconds to run, or can’t connect at all because all connections slots are busy. If you have worked with MySQL long enough you surely have seen it, probably more than once. This is what I would call “MySQL […]

Download insightful MySQL presentations from Percona Live London 2013

The MySQL community came together last month for two days of outstanding technical tutorials and sessions at Percona Live London. And now many of those MySQL presentations are available for free download. This year’s London conference saw a 20 percent spike in attendance compared with last year, with MySQL professionals from 31 countries gathering in […]

Using the new spatial functions in MySQL 5.6 for geo-enabled applications

Geo-enabled (or location enabled) applications are very common nowadays and many of them use MySQL. The common tasks for such applications are: Find all points of interests (i.e. coffee shops) around (i.e. a 10 mile radius) the given location (latitude and longitude). For example we want to show this to a user of the mobile […]

Inexpensive SSDs for Database Workloads

The cost of SSDs has been dropping rapidly, and at the time of this writing, 2.5-drives have reached the 1TB capacity mark.  You can actually get inexpensive drives for as little as 60 cents per GB. Even inexpensive SSDs can perform tens of thousands of IOPs and come with 1.5M – 2M hous MTBF and […]

InnoDB performance optimization basics (redux)

I recently stumbled upon a post that Peter Zaitsev published back in 2007 titled “Innodb Performance Optimization Basics.” It’s a great post and reading it inspired me to examine what’s changed in the nearly six years that have followed in terms of MySQL, Percona Server – as well as in all of the other now-available […]