September 2, 2014

Computing 95 percentile in MySQL

When doing performance analyzes you often would want to see 95 percentile, 99 percentile and similar values. The “average” is the evil of performance optimization and often as helpful as “average patient temperature in the hospital”. Lets set you have 10000 page views or queries and have average response time of 1 second. What does […]

Sphinx 0.9.8 is released just in time for OSCON 2008

As you probably already seen in a post by Baron, Sphinx Release 0.9.8 is finally out, just in time for OSCON 2008. Even though it is “minor release” if you look at the number, it is major release in practice (and you can view snapshots as minor releases). The changes since 0.9.7 are dramatic with […]

Heikki Tuuri Innodb answers – Part I

Its almost a month since I promised Heikki Tuuri to answer Innodb Questions. Heikki is a busy man so I got answers to only some of the questions but as people still poking me about this I decided to publish the answers I have so far. Plus we may get some interesting follow up questions […]


Interesting enough this year people at OSCON do not show to much interest in the MySQL, and Databases for that reason. Our talk comparing performance of MySQL Storage Engines had probably 20-30 people, Monty’s talk on MySQL Source Code had about same number, and as Monty told me he never had so few people on […]

Why do you need many apache children ?

I already wrote kind of about same topic a while ago and now interesting real life case makes me to write again Most Web applications we’re working with have single tier web architecture, meaning there is just single set of apache servers server requests and nothing else – no dedicated server for static content, no […]

Are PHP persistent connections evil ?

As you probably know PHP “mysql” extension supported persistent connections but they were disabled in new “mysqli” extension, which is probably one of the reasons some people delay migration to this extension. The reason behind using persistent connections is of course reducing number of connects which are rather expensive, even though they are much faster […]

Speedup your LAMP stack with LigHTTPD

Apache Web server could frequently be bottleneck for your LAMP stack, or you might be wasting resources on your web servers. The problem with Apache server comes from “client per process” architecture which you have to stick to at least for dynamic content served by PHP or ModPerl. With “client per process” you end up […]