“The least expensive query is the query you never run.” Data access is expensive for your application. It often requires CPU, network and disk access, all of which can take a lot of time. Using less computing resources, particularly in the cloud, results in decreased overall operational costs, so caches provide real value by avoiding [...]
Caching could be the last thing you want to do
July 24, 2010 By 14 Comments
I recently had a run-in with a very popular PHP ecommerce package which makes me want to voice a recurring mistake I see in how many web applications are architected. What is that mistake? The ecommerce package I was working with depended on caching. Out of the box it couldn’t serve 10 pages/second unless I [...]
Beyond great cache hit ratio
May 19, 2010 By 2 Comments
I worked with application recently which has great memcached hit ratio – over 99% but yet still has average page response time over 500ms. Reason ? There are hundreds memcached gets and even though they have some 0.4ms response time they add up to add hundreds of ms to the total response time.
Active Cache for MySQL
January 10, 2010 By 11 Comments
One of the problems I have with Memcache is this cache is passive, this means it only stores cached data. This means application using Memcache has to has to special logic to handle misses from the cache, being careful updating the cache – you may have multiple data modifications happening at the same time. Finally [...]
When would you use SAN with MySQL ?
March 9, 2009 By 18 Comments
One question which comes up very often is when one should use SAN with MySQL, which is especially popular among people got used to Oracle or other Enterprise database systems which are quite commonly deployed on SAN. My question in such case is always what exactly are you trying to get by using SAN ?
How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
Our customers or prospective customers often ask us how we do a performance audit (it’s our most popular service). I thought I should write a blog post that will both answer their question, so I can just reply “read all about it at this URL” and share our methodology with readers a little bit. This [...]
Living with backups
November 6, 2008 By 28 Comments
Everyone does backups. Usually it’s some nightly batch job that just dumps all MySQL tables into a text file or ordinarily copies the binary files from the data directory to a safe location. Obviously both ways involve much more complex operations than it would seem by my last sentence, but it is not important right [...]
MySQL Replication vs DRBD Battles
April 28, 2008 By 12 Comments
Well these days we see a lot of post for and against (more, more) using of MySQL and DRBD as a high availability practice. I personally think DRBD has its place but there are far more cases when other techniques would work much better for variety of reasons. First let me start with Florian’s comments [...]
Choosing innodb_buffer_pool_size
November 3, 2007 By 39 Comments
My last post about Innodb Performance Optimization got a lot of comments choosing proper innodb_buffer_pool_size and indeed I oversimplified things a bit too much, so let me write a bit better description. Innodb Buffer Pool is by far the most important option for Innodb Performance and it must be set correctly. I’ve seen a lot [...]
Getting use of Slave in MySQL Replication
February 14, 2007 By 15 Comments
MySQL Replication is asynchronous which causes problems if you would like to use MySQL Slave as it can contain stale data. It is true delay is often insignificant but in times of heavy load or in case you was running some heavy queries on the master which not take time to replicate to the slave [...]
