As part of Percona Remote DBA for MySQL service we recognize that reliable backups are one of the most important things we can bring to the table. In my experience handling emergencies, the single worst thing that can happen is finding out you don’t have backups available when some sort of data loss or catastrophic [...]
Hidden columns of query_review_history table
August 28, 2012 By Leave a Comment
You can use pt-query-digest to process a MySQL slow query log and store historical values for review trend analysis into query_review_history table. According to its official documentation you can populate many columns in that table but there are other important ones such as ‘user’, ‘host’, ‘db’ which are not included by default. I will explain [...]
Bug#12704861
November 20, 2011 By 1 Comment
As Mark pointed out, there isn’t a lot of detail in the release notes about what could potentially be a very serious problem that is fixed in MySQL 5.1.60. I’ll repeat here the full documentation from the release notes: “InnoDB Storage Engine: Data from BLOB columns could be lost if the server crashed at a precise [...]
InnoDB Flushing: Theory and solutions
April 4, 2011 By 23 Comments
I mentioned problems with InnoDB flushing in a previous post. Before getting to ideas on a solution, let’s define some terms and take a look into theory. The two most important parameters for InnoDB performance are innodb_buffer_pool_size and innodb_log_file_size. InnoDB works with data in memory, and all changes to data are performed in memory. In [...]
Using Flexviews – part two, change data capture
March 25, 2011 By 26 Comments
In my previous post I introduced materialized view concepts. This post begins with an introduction to change data capture technology and describes some of the ways in which it can be leveraged for your benefit. This is followed by a description of FlexCDC, the change data capture tool included with Flexviews. It continues with an [...]
MySQL 5.5.8 and Percona Server on Fast Flash card (Virident tachIOn)
December 21, 2010 By 11 Comments
This is to follow up on my previous post and show the results for MySQL 5.5.8 and Percona Server on the fastest hardware I have in our lab:Â a Cisco UCS C250 server with 384GB of RAM, powered by a Virident tachIOn 400GB SLC card. To see different I/O patterns, I used different innodb_buffer_pool_size settings: 13G, [...]
MySQL-Memcached or NOSQL Tokyo Tyrant – part 1
October 15, 2009 By 16 Comments
All to often people force themselves into using a database like MySQL with no thought into whether if its the best solution to there problem. Why? Because their other applications use it, so why not the new application? Over the past couple of months I have been doing a ton of work for clients who [...]
MySQL for Hosting Providers – how do they manage ?
November 28, 2008 By 15 Comments
Working with number of hosting providers I always wonder how do they manage to keep things up given MySQL gives you so little ways to really restrict how much resources single user can consume. I have written over a year ago about 10+ ways to crash or overload MySQL and since that people have come [...]
How much overhead DRDB could cause ?
June 2, 2008 By 4 Comments
I was working with the customer today investigating MySQL over DRBD performance issues. His basic question was why there is so much overhead with DRBD in my case, while it is said there should be no more than 30% overhead when DRBD is used. The truth is – because how DRBD works it does not [...]
Falcon Storage Engine Design Review
January 12, 2007 By 19 Comments
Now as new MySQL Storage engine – Falcon is public I can write down my thought about its design, which I previously should have kept private as I partially got them while working for MySQL. These thought base on my understanding, reading docs, speaking to Jim, Monty, Arjen and other people so I might miss [...]
