One of the very frequent cases with performance problems with MySQL is what they happen every so often or certain times… need to know it is not MySQL problem, might be even not problem with your MySQL configuration, queries and hardware, even though… a good idea. It also often helps with monopolizing replication thread. For example if I need to delete old data instead…
Post: Troubleshooting MySQL Memory Usage
March 21, 2012 By 3 Comments
…variable which allows you to limit size of MEMORY tables (the limit applies both to … (318747272 + 128560) Recovery system 0 (0 + 0) Threads 425080 (406936 + 18144) Dictionary memory allocated … is where your MySQL Support contract can be handy. Conclusion Understanding where MySQL can allocate …
Post: Announcing Percona XtraBackup 1.9.1
February 27, 2012 By 9 Comments
…. It is now possible to stream incremental backups, lifting a limitation from previous versions where it was only possible to stream… –compress –compress-threads=2′ will create 4 IO threads that will read the data and pipe it to 2 compression threads. New streaming…
Post: Announcing Percona XtraBackup 2.0.0 GA
April 4, 2012 By 11 Comments
… streaming backups + external (usually single-threaded) compression utilities, which also had a number of other limitations (e.g. could not be used… be part of the topics at the upcoming Percona Live MySQL Conference and Expo (register now!). Specifically, there are the following…
Post: MySQL Limitations Part 4: One thread per connection
October 27, 2010 By 14 Comments
… seriously limiting MySQL in core use cases (links: part 1, 2, 3). This post is about the way MySQL handles connections, allocating one thread per connection to the server. MySQL is a single process with multiple threads. Not all…’s why I listed those as major limitations. And because MySQL is a multi-threaded database for Web usage that tends to be…
Post: Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
…MySQL manual, especially the …thread_cache_sizeblogpercona.commanual thread_concurrencyblogpercona.commanual thread_handlingblogpercona.commanual thread_stackblogpercona.commanual Threads_cachedblogpercona.commanual Threads_connectedblogpercona.commanual Threads_createdblogpercona.commanual Threads…
Post: MySQL Limitations Part 1: Single-Threaded Replication
October 20, 2010 By 16 Comments
…” limitations Postgres has overcome for specific use cases. I decided to write a series of blog posts on MySQL‘s unsolved severe limitations. I mean limitations that really hobble it for major, important… the replication events to the appropriate thread. A pool of threads on the replica, and a coordinating thread that hands work to each…
Post: Configuring MySQL For High Number of Connections per Second
January 6, 2012 By 17 Comments
…on operating system size to allow MySQL to handle spikes. Although MySQL connections are quite fast compared … which means even very short stall in main thread which is accepting connections will cause for …getting pretty close to what could be the limit and you should consider techniques to reduce …
Post: MySQL Users Conference - Innodb
May 9, 2007 By 6 Comments
… to build indexes in parallel by running sorts in different threads – using multiple cores becomes increasingly important as their number per… a lot of “Gotches” while many of them come from MySQL limits at the time when Innodb was first implemented. Many other… to MySQL 5.0+ Heikki also mentioned there are more things inside Innodb to unleash performance such as multiple purge threads or…
Post: Implementing Parallel Replication in MySQL
November 8, 2010 By 3 Comments
… considering implementing a limited form of parallel replication. Single-threaded replication is one of the most severe limitations in the MySQL server. We have… lift some of the restrictions. We will initially impose these limitations to keep things simple, and make sure we can actually…
