October 25, 2014

How to check MySQL Config files

Probably most of MySQL users sometime had a situation when they would do changes in MySQL config file without restarting server (may be matching SET GLOBAL command to do it in run time) but either because option is misspelled or because given version does not support such option the server when would refuse to start […]

Check for MySQL slave lag with Percona Toolkit plugin for Tungsten Replicator

A while back, I made some changes to the plugin interface for pt-online-schema-change which allows custom replication checks to be written. As I was adding this functionality, I also added the –plugin option to pt-table-checksum. This was released in Percona Toolkit 2.2.8. With these additions, I spent some time writing a plugin that allows Percona […]

Looking to upgrade to MySQL 5.6? Check out my webinar on Jan 29!

We are nearing the one-year anniversary since MySQL 5.6 went GA – which is typically a good time even for the most conservative users to start thinking about upgrading. At this point there is a fair amount of practical use and experience; many bugs have also been fixed (1991 to be exact according to Morgan […]

InnoDB adaptive flushing in MySQL 5.6: checkpoint age and io capacity

In MySQL 5.6 InnoDB has a dedicated thread (page_cleaner) that’s responsible for performing flushing operations. Page_cleaner performs flushing of the dirty pages from the buffer pool based on two factors: – access pattern  –  the least recently used pages will be flushed by LRU flusher from LRU_list when buffer pool has no free pages anymore; […]

Replication checksums in MySQL 5.6

MySQL 5.6 has an impressive list of improvements. Among them, replication checksums caught my attention as it seems that many people misunderstand the real added value of this new feature. I heard people think that with replication checksums, data integrity between the master and its replicas is now enforced. As we’ll see, it’s not that […]

Introducing the pmp-check-mysql-status Nagios Plugin

Most of the Nagios plugins included with the Percona Monitoring Plugins are purpose-built for specific scenarios that I found in my research to be frequent, severe, or subtle causes of problems in MySQL systems. They are intentionally not generic because I wanted to focus on doing one thing with each plugin, and doing it excellently. […]

DBD::mysql 4.014 breaks pt-table-checksum 2.0

DBD::mysql 4.014 breaks pt-table-checksum 2.0.  The cause is unknown, but the effect is a lot of errors like: DBD::mysql::st execute failed: called with 2 bind variables when 6 are needed [for Statement "..." with ParamValues: ...] at ./pt-table-checksum line 7216. The fix is simple: upgrade (or even downgrade) DBD::mysql to any version except 4.014. To […]

The new cool MySQL patch has landed! Check your queries performance!

Microslow patch is used by many DBAs and developers to accurately time their queries and to catch those which run less than a second as they can also be a performance killer for a busy application. Recently I have started the development of an updated version of the patch. The basic idea is the same […]

Autumn: A season of MySQL-related conferences. Here’s my list

Autumn is a season of MySQL-related conferences and I’m about to hit the road to speak and attend quite a  few of them. This week I’ll participate in All Things Open, a local conference for me here in Raleigh, N.C. and therefore one I do not have to travel for. All Things Open explores open source, […]

Percona Toolkit for MySQL with MySQL-SSL Connections

I recently had a client ask me how to use Percona Toolkit tools with an SSL connection to MySQL (MySQL-SSL). SSL connections aren’t widely used in MySQL due to most installations being within an internal network. Still, there are cases where you could be accessing MySQL over public internet or even over a public “private” […]