Linux System Admins Blog

System admins of Promet – an e-commerce, high availability Open Source web shop – share their findings

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Entries Tagged as 'Performance'

Google to offer free DNS service

December 3rd, 2009 · 1 Comment

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 [...]

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Tags: Performance · cloud computing

Tracing memory leaks with pidstat

June 16th, 2009 · No Comments

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 [...]

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Tags: Performance · sysadmin

MySQL Query Cache, Good or Bad?

April 21st, 2009 · 1 Comment

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 [...]

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Tags: MySQL · Performance

Drupal performance tips from DrupalCon

March 5th, 2009 · 1 Comment

increasing drupal performance notes from drupal con dc 2009

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Tags: Performance · drupal · monitoring

Cloud computing scenario’s for database servers

February 17th, 2009 · No Comments

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 [...]

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Tags: Down Time · MySQL · Performance · Replication · hosting

Extending the slow query log

February 4th, 2009 · No Comments

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 [...]

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Tags: MySQL · Performance

Web site slow? To improve performance – Sys Admins may be of little help – call the designer

January 30th, 2009 · 1 Comment

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 [...]

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Tags: Performance

MySQL query optimization for network throughput

December 10th, 2008 · No Comments

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 [...]

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Tags: MySQL · Performance

When MySQL starts counting sheep

September 4th, 2008 · No Comments

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. [...]

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Tags: MySQL · Performance · monitoring

Enabling and using the slow query log in MySQL

August 26th, 2008 · 2 Comments

By special request here is a post about the MySQL slow query log. MySQL has a wonderful feature that lets you keep track of all queries that took longer than a certain time to complete. To enable it simply add the following line to your my.cnf file:
log-slow-queries = [path to the log file]
Secondly it is [...]

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Tags: MySQL · Performance