… open_files_limit set to 40000? 2) Could you explain the difference between MyISAM and InnoDB and the difference in how the OS handles opened files… innodb_additional_mem_pool_size = 8M innodb_log_file_size = 256M innodb_log_files_in_group = 2 innodb_thread_concurrency = 16 innodb_open_files = 20000 innodb_flush_method = O_DIRECT innodb…
Comment: table_cache negative scalability
April 14, 2010 By 23 Comments
… the open_files_limit set to 40000? 2) Could you explain the difference between MyISAM and InnoDB table cache?…innodb_additional_mem_pool_size = 8M innodb_log_file_size = 256M innodb_log_files_in_group = 2 innodb_thread_concurrency = 16 innodb_open_files = 20000 innodb_flush_method = O_DIRECT innodb…
Post: How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
… find that there are InnoDB tables whose .frm files exist but have been dropped from InnoDB, for example. (… log output. The stock MySQL server’s limitation of one-second granularity makes it hide …. It’s like knowing openings in chess — the great chess players study openings exhaustively, but they …
Post: Updated msl (microslow) patch, installation walk-through!
April 20, 2008 By 17 Comments
…you have it all in place, we can begin. Open command line (shell) on the server and go…min_examined_row_limit=# Don’t log queries which examine less than min_examined_row_limit rows to file. If…InnoDB extensions msl patch for MySQL 5.0.51a with InnoDB extensions msl patch for MySQL 5.0.54a with InnoDB…
Comment: How innodb_open_files affects performance
April 14, 2010 By 4 Comments
… “open files“, mysql setting “open_file_limit” affects the OS/MySQL and I believe is non-biased to MyISAM and InnoDB table types. If the max open_file_limit is 65535, does this mean a linux 64bit server could never have more than that opened…
Comment: Database problems in MySQL/PHP Applications
November 6, 2006 By 13 Comments
… = 2000M max_allowed_packet = 32M # table_cache=20M # open-files-limit=20000 table_cache = 3072 open_files_limit = 9216 tmp_table_size=1000M sort_buffer_size…_file_size to 25 % of buffer pool size innodb_log_file_size = 1000M #innodb_log_buffer_size = 32M #innodb_flush_log_at_trx_commit = 1 #innodb…
Post: MySQL opening .frm even when table is in table definition cache
November 21, 2011 By 8 Comments
…to opening the FRM files to read the table definition, but we can see from strace: [pid 19876] open… engine it is. We can ignore the upper limit on number of storage engines for MySQL …in InnoDB itself and in the table_definition_cache). Further reading: MySQL Forge Internals document on the FRM file…
Post: Announcing Percona Server for MySQL version 5.5.29-30.0
February 26, 2013 By Leave a Comment
…Laurynas Biveinis). The XtraDB used to print the open read view list without taking the kernel…innodb_flush_method=O_DIRECT was set up, log bitmap files were created and treated as InnoDB data files…errors. Fixed by renaming the innodb_changed_pages_limit option to innodb_max_changed_pages. Bug fixed …
Post: Virtualization and IO Modes = Extra Complexity
March 21, 2011 By 12 Comments
… pretty confident running Innodb with both default (fsync based) or O_DIRECT innodb_flush_method. …Doing random write test Threads started! Time limit exceeded, exiting… Done. Operations performed: 0 Read,… threads: 1 Extra file open flags: 16384 1 files, 1Mb each 1Mb total file size Block size 16Kb…
Comment: Why MySQL could be slow with large tables ?
June 21, 2006 By 141 Comments
… to avoid constant table reopens. With Innodb tables you also have all tables kept open permanently which can waste a lot of memory but it is other problem. Speaking about “open_file_limit” which limits number of files MySQL… high values. I used MySQL with other 100.000 of files opened at the same time with no problems. Shutdown can be…
