… introduced a regression that could cause a memory leak if query cache was used together with InnoDB. Bug fixed #1170103. Fixed the… #1171941. Fixed the CVE-2012-5627 vulnerability, where an unprivileged MySQL account owner could perform brute-force password guessing attack on… MDEV-3915). Bug fixed #1172090. mysql_set_permission was failing on Debian due to missing libdbd-mysql-perl package. Fixed by adding the…
Post: MySQL and the SSB - Part 2 - MyISAM vs InnoDB low concurrency
May 22, 2013 By Leave a Comment
… consists of four sets of queries. Each set is known as a “flight”. I have labeled each query as Q{FLIGHT_NUMBER}.{QUERY_NUMBER}. In… the hot test. All OS caches are dropped at this time as well. These set of queries were tested on the SSB at… [mysqld] datadir=/mnt/mysql56/data basedir=/usr/local/mysql socket=/var/lib/mysql/mysql.sock user=justin innodb_buffer_pool_size=64G innodb…
Post: Rotating MySQL slow logs safely
April 18, 2013 By 7 Comments
… a solution for keeping the caches of a MySQL standby server hot using MySQL slow logs with long_query_time set to 0. Here are… mysql mysql size 1G dateext missingok notifempty sharedscripts postrotate /usr/local/bin/mysql -e ‘select @@global.long_query_time into @lqt_save; set global long_query…
Post: Is your MySQL buffer pool warm? Make it sweat!
April 16, 2013 By 6 Comments
… accessed pages. When it starts handling queries after failover, the lower cache hit rates can lead to outages. …mysql-username playback –mysql-password PaSSwOrd –mysql-schema schema_name –query-log-stdin –dispatcher-plugin thread-pool –thread-pool-threads-count 100 –session-init-query \”set…
Post: Virident vCache vs. FlashCache: Part 2
May 17, 2013 By 3 Comments
… designed to look solely at vCache performance under some different sets of MySQL configuration parameters. For example, given that the front-end…_cache_size = 16M max_heap_table_size = 64M sort_buffer_size = 4M join_buffer_size = 4M thread_cache_size = 1000 query_cache_size = 0 query_cache…
Post: MySQL 5.6 - InnoDB Memcached Plugin as a caching layer
March 29, 2013 By 10 Comments
… MySQL 5.6 is to use a caching layer to store expensive result sets or objects. Some typical use cases include: Complicated query result set… the entire cache is cleared (think restarting a memcache node). This is where a persistent cache can be invaluable. Enter MySQL 5.6… (~.06 ms/op) MySQL Select showed 27% increase over InnoDB fetch (~.09 ms/op) This replaced $cache->load() with $db->query(“SELECT * FROM…
Post: Benchmarking Percona Server TokuDB vs InnoDB
May 7, 2013 By 32 Comments
…cache_size = 16M max_heap_table_size = 64M sort_buffer_size = 4M join_buffer_size = 4M thread_cache_size = 1000 query_cache_size = 0 query_cache…threads = 1 myisam_recover socket=/var/lib/mysql/mysql.sock user=root skip-grant-… from documentation TokuDB comes with good settings out-of-box, but I …
Comment: MySQL Partitioning - can save you or kill you
April 30, 2013 By 45 Comments
…Insert’ part. 1. With a standard numeric key id, set as a Primary Key, it will probably be … of the partitions, the whole partition can be cached, as opposed to a single table, where probably …you do queries on any other column, these could easily be quicker on a partitioned table, as Mysql can …
Post: MySQL Query Cache
July 27, 2006 By 70 Comments
… MySQL Query Cache is the same as Oracle Query Cache – meaning cache where execution plans are cached. MySQL Query Cache is not. It does not cache the plan but full result sets… in “Cache everything” mode. In certain caches you might want to cache only some of the queries – in this case you can set query_cache_type to…
Post: Write contentions on the query cache
September 5, 2012 By 5 Comments
… contention issues was the query cache as it was enabled. Contention on the query cache mutex when checking if the result set can be served… was: why did MySQL need so many accesses to the query cache lock? The answer is in the way the query cache works. Simply stated… lock the query cache both when checking if a result is in the cache and when writing a result set into the cache. When writing…
