There are times where you need to know exactly how much memory the mysqld server (or any other program) is using, where (i.e. for what function) it was allocated, how it got there (a backtrace, please!), and at what point in time the allocation happened. For example; you may have noticed a sharp memory increase [...]
Is there room for more MySQL IO Optimization?
January 3, 2013 By 11 Comments
I prefer to run MySQL with innodb_flush_method=O_DIRECT in most cases – it makes sure there is no overhead of double buffering and I can save the limited amount of file system cache I would normally have on database server for those things which need to be cached — system files, binary log, FRM files, MySQL [...]
Percona Toolkit Webinar followup Q&A
December 19, 2012 By 1 Comment
First, a thank you to everyone who attended the webinar Today, I appreciate your time and nice comments. As promised, here are answers to questions that couldn’t be answered during the talk: Q: How do you install the tools? The manual has full details, but it’s important to know that the latest release for [...]
The Optimization That (Often) Isn’t: Index Merge Intersection
December 14, 2012 By 6 Comments
Prior to version 5.0, MySQL could only use one index per table in a given query without any exceptions; folks that didn’t understand this limitation would often have tables with lots of single-column indexes on columns which commonly appeared in their WHERE clauses, and they’d wonder why the EXPLAIN plan for a given SELECT would [...]
Realtime stats to pay attention to in Percona XtraDB Cluster and Galera
November 26, 2012 By 4 Comments
I learn more and more about Galera every day. As I learn more, I try to keep my myq_gadgets toolkit up to date with what I consider is important to keep any eye on on a PXC node. In that spirit, I just today pushed some changes to the ‘wsrep’ report, and I thought I’d go over [...]
Announcing Percona XtraDB Cluster 5.5.28-23.7
November 15, 2012 By 9 Comments
Percona is glad to announce the release of Percona XtraDB Cluster on November 15th, 2012. Binaries are available from downloads area or from our software repositories. Features: Percona XtraDB Cluster has ported Twitter’s MySQL NUMA patch. This patch implements improved NUMA support as it prevents imbalanced memory allocation across NUMA nodes. Number of binlog files [...]
Visualization tools for pt-query-digest tables
August 31, 2012 By 6 Comments
When you process MySQL slow query logs using pt-query-digest you can store samples of each query into query_review table and historical values for review trend analysis into query_review_history table. But it could be difficult to easily browse those tables without a good GUI tool. For the visual browsing of tables created by pt-query-digest you may [...]
Here’s a quick way to Foresee if Replication Slave is ever going to catch up and When!
August 29, 2012 By 11 Comments
If you ever had a replication slave that is severely behind, you probably noticed that it’s not catching up with a busy master at a steady pace. Instead, the “Seconds behind master” is going up and down so you can’t really tell whether the replica is catching up or not by looking at just few [...]
Sell-an-Elephant-to-your-Boss-HOWTO
August 28, 2012 By 3 Comments
Spoiler alert: If your boss does not need an elephant, he is definitely NOT going to buy one from you. If he will, he will regret it and eventually you will too. I must appologize to the reader who was expecting to find an advice on selling useless goods to his boss. While I do [...]
Full Text Search Webinar Questions Followup
August 24, 2012 By 5 Comments
I presented a webinar this week to give an overview of several Full Text Search solutions and compare their performance. Even if you missed the webinar, you can register for it, and you’ll be emailed a link to the recording. During my webinar, a number of attendees asked some good questions. Here are their questions and my [...]
