Hello Josh, why you moved your table to InnoDB? Your description doesn't sound like the tables rows are accessed concurrently and need to be locked? Are you sure you need InnoDB for this table?
If you need InnoDB you probably need to redesign your queries and table structure to get them more convenient for InnoDB. With kind regards, TomH -----Original Message----- From: Josh Miller [mailto:[EMAIL PROTECTED] Sent: Thursday, September 04, 2008 10:27 PM To: mysql@lists.mysql.com Subject: innodb/myisam performance issues Good afternoon, I have recently converted a large table from MyISAM to InnoDB and am experiencing severe performance issues because of it. HTTP response times have gone from avg .25 seconds to avg 2-3 seconds. Details follow: PHP/MySQL website, no memcached, 3 web nodes that interact with DB, one that serves images, one master DB that serves all reads/writes, backup DB that only serves for backup/failover at this time (app being changed to split reads/writes, not yet). The one table that I converted is 130M rows, around 10GB data MyISAM to 22GB InnoDB. There are around 110 tables on the DB total. My.cnf abbreviated settings: [mysqld] port = 3306 socket = /tmp/mysql.sock skip-locking key_buffer = 3G sort_buffer_size = 45M max_allowed_packet = 16M table_cache = 2048 tmp_table_size = 512M max_heap_table_size = 512M myisam_sort_buffer_size = 512M myisam_max_sort_file_size = 10G myisam_repair_threads = 1 thread_cache_size = 300 query_cache_type = 1 query_cache_limit = 1M query_cache_size = 600M thread_concurrency = 8 max_connections = 2048 sync_binlog = 1 innodb_buffer_pool_size = 14G innodb_log_file_size = 20M innodb_flush_log_at_trx_commit=1 innodb_flush_method = O_DIRECT skip-innodb-doublewrite innodb_support_xa = 1 innodb_autoextend_increment = 16 innodb_data_file_path = ibdata1:40G:autoextend We're seeing a significantly higher percentage of IO wait on the system, averaging 20% now with the majority of that being user IO. The system is not swapping at all. Any ideas for what to check or modify to increase the performance here and let MyISAM and InnoDB play better together? The plan is to convert all tables to InnoDB which does not seem like a great idea at this point, we're considering moving back to MyISAM. Thanks! Josh Miller, RHCE -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED] -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
