At Percona we offer a number of services. One of them, Custom MySQL Server Development, is commonly the most misunderstood and undervalued. There are a lot of ways Percona custom MySQL server development can help your business be more successful with MySQL. Here are some ways: Bugs – There are Bugs in MySQL, Percona Server, [...]
Profiling MySQL Memory Usage With Valgrind Massif
January 9, 2013 By 1 Comment
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 [...]
Replication of the NOW() function (also, time travel)
November 28, 2012 By 6 Comments
Notice the result of the NOW() function in the following query. The query was run on a real database server and I didn’t change the clock of the server or change anything in the database configuration settings.
1 2 3 4 5 6 7 | mysql> SELECT NOW(),SYSDATE(); +---------------------+---------------------+ | NOW() | SYSDATE() | +---------------------+---------------------+ | 1999-01-01 00:00:00 | 2012-11-29 05:50:03 | +---------------------+---------------------+ 1 row in set (0.00 sec) |
You may proceed to party like it is 1999. How can the NOW() function return a value [...]
Get Me Some Query Logs!
November 22, 2012 By 14 Comments
One of my favorite tools in the Percona Toolkit is pt-query-digest. This tool is indispensable for identifying your top SQL queries, and analyzing which queries are accounting for your database load. But the report you get from pt-query-digest is only as good as the log of queries you give it as input. You need a large [...]
Percona XtraDB Cluster – installation and setup webinar follow up Q&A
October 28, 2012 By 4 Comments
Thanks for all, who attended my webinar, I got many questions and I wanted to take this opportunity to answer them. Q: Even ntp has a delay of 0.3-0.4 between servers does that mean a 0.25 as from logs can be an issue ? A: My demo vms were running for a few hours before [...]
Review of MySQL 5.6 Defaults Changes
October 8, 2012 By 10 Comments
James Day just posted the great summary of defaults changes in MySQL 5.6 compared to MySQL 5.5 In general there are a lot of good changes and many defaults are now computed instead of hardcoded. Though some of changes are rather puzzling for me. Lets go over them: back_log = 50 + ( max_connections / [...]
Percona XtraDB Cluster: Failure Scenarios with only 2 nodes
July 25, 2012 By 6 Comments
During the design period of a new cluster, it is always advised to have at least 3 nodes (this is the case with PXC but it’s also the same with PRM). But why and what are the risks ? The goal of having more than 2 nodes, in fact an odd number is recommended in [...]
Comparing Percona XtraDB Cluster with Semi-Sync replication Cross-WAN
June 14, 2012 By 7 Comments
I have a customer who is considering Percona XtraDB Cluster (PXC) in a two colo WAN environment. They wanted me to do a test comparing PXC against semi-synchronous replication to see how they stack up against each other. Test Environment The test environment included AWS EC2 nodes in US-East and US-West (Oregon). The ping RTT latency [...]
Percona Toolkit versions 2.0.5 and 2.1.2 released
June 12, 2012 By 1 Comment
The Percona Toolkit team is happy to announce the release of Percona Toolkit versions 2.0.5 and 2.1.2. These are bug-fix releases in the 2.0 and 2.1 series, respectively. These releases fix many dozens of bugs, and we suggest that users upgrade to the latest versions of the tools. The complete list of changes is on [...]
Migrating to XtraDB Cluster Webinar follow up questions
June 6, 2012 By 3 Comments
Thanks to all who attended my webinar today. The session was recorded and will be available to watch for free soon here. There were a lot of great questions asked during the session, so I’d like to take this opportunity to try to answer a few of them: Q: Is there an easy way to [...]
