…MYSQL server and found that Percona need some configuration setting regarding to memory allocation. So we did some memory… performance degradation started and now it is slow again. MySQL load is not going very high….- 5.3.3 MySQL – 5.1.66 [Percona XtraDB Cluster (GPL) (5.5.30)] (InnoDB Engine) PHP My …
Comment: Investigating MySQL Replication Latency in Percona XtraDB Cluster
May 17, 2013 By 13 Comments
Post: Troubleshooting MySQL Memory Usage
March 21, 2012 By 5 Comments
…MySQL in wild. I also wanted to share some troubleshooting techniques I use. Plot Memory Usage First I would like to see MySQL memory…memory is being used by current MEMORY tables: mysql> select sum(data_length+index_length) from information_schema.tables where engine=’memory…
Post: Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
…MySQL manual,…engine_logsblogpercona.commanual Com_show_engine_mutexblogpercona.commanual Com_show_engine…commanual shared_memory_base_…Slow_launch_threadsblogpercona.commanual slow_launch_timeblogpercona.commanual Slow_queriesblogpercona.commanual slow_query_logblogpercona.commanual slow…
Post: Detailed review of Tokutek storage engine
April 28, 2009 By 21 Comments
…circulating that TokuDB is â€.. only an in memory or read-only engine, and that’s why inserts are so…MySQL 6.0, but I can’t yet say how it will work with mix of storage engines. – The Tokutek engine…us the problem of random IO, waste of RAM memory and slow inserts. This is where I think Tokutek …
Post: Why MySQL could be slow with large tables ?
June 9, 2006 By 141 Comments
… may not work well for MySQL and other way around. Even storage engines have very important differences … In fact even MySQL optimizer currently does not take it into account. For In memory workload index accesses…bound can be very slow. One of the reasons elevating this problem in MySQL is lack of …
Post: Side load may massively impact your MySQL Performance
November 13, 2011 By 7 Comments
…-driver=mysql –mysql-host=localhost –mysql-table-engine=innodb –mysql-db=test –oltp-table-name=md_cache_test_small –oltp-table-size=1100000 –mysql-user=msandbox –mysql… happen the workload which is normally in memory becomes disk IO bound which can slow it down more than 100 times. The…
Post: DROP TABLE and stalls: Lazy Drop Table in Percona Server and the new fixes in MySQL
June 22, 2012 By 33 Comments
… –oltp-table-size=20000000 –mysql-table-engine=innodb –mysql-socket=/tmp/mysql_sandbox5524.sock –mysql-db=test –oltp-…for analysis purposes the queries in the slow log were grouped by their timestamp, …so that the dataset completely fits in memory, and to prevent checkpointing from skewing the…
Post: MySQL 5.5 and MySQL 5.6 default variable values differences
February 21, 2013 By 8 Comments
… 1 | 8 | | QUERY_CACHE_SIZE | 0 | 1048576 | | SLOW_QUERY_LOG_FILE | /mnt/data/sandboxes/…_MAX_FILE_INSTANCES | 10000 | 1556 | | SQL_MODE | | NO_ENGINE_SUBSTITUTION | | INNODB_OLD_BLOCKS_TIME | 0 | 1000 | | LOG…1MB now allowing MySQL to handle larger queries. Makes sense as amount of memory available …
Post: MySQL Indexing Best Practices: Webinar Questions Followup
August 16, 2012 By 4 Comments
… null, PRIMARY KEY(id1,id2), KEY K(id2)) engine=INNODB; when table has to be traversed in… slow down your inserts and make primary key significantly fragmented. I also would note there are some MySQL … of indexes. The indexes can’t fit in memory anymore. How does this affect performance? A: Typically …
Post: MySQL Server Variables - SQL layer or Storage Engine specific.
June 8, 2006 By 14 Comments
… not that many storage engines – there was MyISAM for disk tables and HEAP for in memory tables. So first MySQL versions did not bother naming variables with storage engines prefix. This is why… master. It does not affect Innodb and other storage engines transaction logs, slow query log or general log. flush, flush_time Flushing…
