June 20, 2013

Post: State of MySQL Market and will Replication live ?

April 9, 2008 By 29 Comments

… few things happen – MySQL kept being “simple” and introduced relatively simple performance boosters – Query Cache and Replication, which were clearly not enough to…. There were a lot of custom technologies created for caching or scalability issues MySQL could not solve well. There are inhouse and…

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Comment: MySQL caching methods and tips

April 7, 2011 By 5 Comments

… cached? How long of an expiration time do you want? How do you clear cache entries manually when your data changes before the cache expiration? Nice things about the query cache: it’s nearly… yourself more fine control over which queries deserve to be cached, but still let MySQL handle cache invalidation transparently.

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Post: Aligning IO on a hard disk RAID – the Benchmarks

June 9, 2011 By 13 Comments

… make sure caches were clean. OLTP benchmark As the goal was to compare performance with different IO alignment, not different MySQL configurations, I didn’t try out different MySQL versions or settings. Moreover, I have… I launched the system that I was benchmarking, I could clearly see the difference in production as I had another machine…

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Post: More on dangers of the caches

September 23, 2010 By 5 Comments

… answer lies in caching as well. When software is deployed the memcache is cleared to avoid potential issues with different cache content, so system have to start with cold cache which overloads the… err when it tries to put too much load on MySQL as MySQL load stabilizes increasing number of connections higher until you…

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Post: How Percona does a MySQL Performance Audit

November 24, 2008 By 17 Comments

…mysql –user=mysql –pid-file=/var/run/mysqld/mysqld.pid –skip-external-locking –port=3306 –socket=/var/db/mysql/mysql…clients | 205174 | | Aborted_connects | 29 | | Binlog_cache_disk_use | 0 | | Binlog_cache_use | 9630066 | | Bytes_received | … output, so it’s clear what I’m showing them…

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Post: Index Condition Pushdown in MySQL 5.6 and MariaDB 5.5 and its performance impact

March 12, 2012 By 12 Comments

… in preparation for the talk comparing the optimizer enhancements in MySQL 5.6 and MariaDB 5.5. We are taking a… optimizer enhancement Index Condition Pushdown (ICP). Its available in both MySQL 5.6 and MariaDB 5.5 Now let’s take…

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Post: Crashes while using MyISAM with multiple key caches

July 18, 2009 By Leave a Comment

… of years I have ran into random MySQL crashes in production when multiple key caches were used. Unfortunately this never was frequent… it was only fixed in MySQL 5.1 while even though bug closed MySQL 5.0 and MySQL 4.1 still did not… is can be found as active bug and it is clear these versions still have it. Or may be have some…

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Post: Filling the tmp partition with persistent connections

August 6, 2012 By 14 Comments

… of disk space on /tmp/partition. The first step is clear, check which files are on that partition: # ls -lah /tmp… DATA INFILE MySQL send the rows to the Binary Log Cache before writing it to the Binary Log Files. If that cache is… physical memory, most likely killing system in the end. Conclusion MySQL can creates temporary files even thought those temporary files are…

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Post: InnoDB Full-text Search in MySQL 5.6 (part 1)

February 26, 2013 By 1 Comment

….ibd -rw-rw—-. 1 mysql mysql 98304 Feb 20 16:09 FTS_00000000000000ad_DELETED_CACHE.ibd -rw-rw—-. 1 mysql mysql 98304 Feb 20 16….ibd -rw-rw—-. 1 mysql mysql 98304 Feb 20 15:54 FTS_0000000000000114_DELETED_CACHE.ibd -rw-rw—-. 1 mysql mysql 98304 Feb 20 15….innodb_ft_index_table is changing, so it’s pretty clear that I do actually have a FT index available. At…

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Post: Caching could be the last thing you want to do

July 24, 2010 By 14 Comments

…features which were designed to be “optional” (but clearly they weren’t). I think with great … hidden. Cache management is really hard – have you planned for cache stampeding, or many cache items being …digest to capture queries.  Run them through MySQL‘s EXPLAIN command. Do your queries SELECT *, …

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