Linux System Admins Blog

APC (Alternative PHP Cache) is a free, open, and robust framework for caching and optimizing PHP intermediate code. APC is a great tool to speed up a php driven site and I can’t even think of a big site running on a php framework without an opcode cache (other good choices are eaccelerator or xcache). [...]

[Read more →]

Google will start pushing for a faster web next year, and there have been several rumors in the SEO and marketing world that google will add page speed to its SEO rankings algorithm.  Yesterday they have announced that  Google will offer a free DNS service.
First off, this is great.  It should improve the speed of [...]

[Read more →]

Finding application memory leaks is important part of keeping systems stable and often very hard to track down. Monitoring application memory consumption can be performed in a few different ways, the easiest is a simple capture of ps and append to log file triggered via cron at desired interval. In this example we will track [...]

[Read more →]

MySQL has a number of different caches. Most of those are dependent on the storage engine that is used. The key buffer for example caches the indexes for MyISAM tables while the caching of data is left to the OS. InnoDB has the buffer pool for both data and indexes and so on. The query [...]

[Read more →]

increasing drupal performance notes from drupal con dc 2009

[Read more →]

We’ve been investigating the possibilities of using cloud computing for our clients. Especially Amazon EC2 has the potential to be be really effective in offering flexible, pay-as-you-go computing. From my own perspective I have been looking at how to use cloud computing in combination with MySQL and I must say that I’m a bit sceptical [...]

[Read more →]

Andy posted some very good links recently to video’s on how to optimize your web site. Although I spend more time optimizing the database you always have to go where the actual performance is lost. For MySQL the place to check for performance issues is the slow query log which I have mentioned in earlier [...]

[Read more →]

Here are two videos by Steve Souders, former chief performance Yahoo, currently at Google.  He determined that 95% of the wait on loading the Yahoo page is after the initial apache response is sent to the browser.  Doing more research he determined that this is about a 80/20 rule on most popular web sites.  It [...]

[Read more →]

It’s a bit of a long title for a blog post but the point I want to make is that not every query optimization is aimed at making the query faster. As a case in point we have a client that has a web shop and their network traffic between the web servers and the [...]

[Read more →]

We encountered a situation recently where the number of connections to our MySQL database started creeping up slowly but steadily. Strangely enough all the connections were in sleep mode and the database was not being stressed. The number of connections first reached 30 where it normally stays below 20 and started triggering our monitoring scripts. [...]

[Read more →]