Harmony disharmony. Microsoft’s Android revenue. And more.[Read more...]
Vadim and others have pointed at the index->lock problems before, but I think they didn’t good job enough at pointing out how bad it can get (the actual problematic was hidden somewhere as some odd edge case). What ‘index lock’ means is generally the fact that InnoDB has table-level locking which will kill performance on big tables miserably.
InnoDB is a huge pie of layers, that have various locking behaviors, and are layered on top of each other, and are structured nicely as subdirectories in your innodb_plugin directory. Low …[Read more...]
Facebook recently updated their PHP-SDK to version 3.0. This is a major change. So I decided to update some of my facebook related tutorials with updated code.
At first I want to tell you that, this post is the updated version of my popular post Graph API & IFrame Base Facebook Application Development . So if you never saw that tutorial I …[Read more...]
There are multiple metrics that are really useful for read workload analysis, that should all be tracked and looked at in performance-critical environments.
The most commonly used is of course Questions (or ‘Queries’, ‘COM_Select’) – this is probably primary finger-pointing metric that can be used in communication with different departments (“why did your qps go up by 30%?”) – it doesn’t always reveal actual cost, it can be increase of actual request rates, it can be new feature, it can be fat fingers error somewhere in the code or improperly handled cache failure.
Another important to note is …[Read more...]
I always have difficulties with complex analysis schemes, so fall back to something that is somewhat easier. Or much easier. Here I will explain the super-powerful method of database write workload analysis.
Doing any analysis on master servers is already too complicated, as instead of analyzing write costs one can be too obsessed with locking and there’s sometimes uncontrollable amount of workload hitting the server beside writes. Fortunately, slaves are much better targets, not only because writes there are single-threaded, thus exposing every costly I/O as time component, but also one can drain traffic from slaves, or send more in order to cause more natural …[Read more...]
Digia gets Qt. VMware makes waves. Rackspace launches OpenStack support. And more.
# Digia signed an agreement with Nokia to acquire the Qt commercial licensing and services business.
# VMware’s Springsource division …[Read more...]
I remember various discussions in different mediums where people were building cases against use of FORCE INDEX in SQL queries. I’ll hereby suggest it using way more often, but at first I’ll start with small explanation.
For ages, the concept of index statistics affecting query plans has been clogging minds of DBAs, supported by long explanations of MyISAM and InnoDB manuals. Actually, statistics are used just for determining which index to use for …[Read more...]
Mark Callaghan has graciously accepted to be the closing keynote speaker for Percona Live: San Francisco!
Mark is best known for his work behind MySQL @ Facebook, where he and his team maintain one of the largest MySQL installations around. They also contribute back to the community with a publicly available branch of enhancements, improved …[Read more...]
A special extended edition of Tech Messages for 2011-01-07 through 2011-01-08: