… with them about their MySQL backup product. One of the representatives told me that their backup product uses FLUSH TABLES WITH READ LOCK… that “Flushing tables” is a misnomer — connection 5 is not flushing tables yet. It’s waiting to get the lock. Flushing tables After the FLUSH TABLES WITH READ… dirty blocks in the operating system buffer cache. This can take a long time to flush. During that time, the entire system…
Post: Is there room for more MySQL IO Optimization?
January 3, 2013 By 11 Comments
I prefer to run MySQL with innodb_flush_method=O_DIRECT in most cases – it makes sure there … which need to be cached — system files, binary log, FRM files, MySQL MyISAM system tables etc. Starting MySQL 5.5 MySQL uses asynchronous IO which… reflect natural state of the table as it would be in the production over time: mysql> show table status like “post_channel” \G…
Post: Multiple purge threads in Percona Server 5.1.56 and MySQL 5.6.2
May 3, 2011 By 13 Comments
… innodb_log_file_size=1900M innodb_flush_log_at_trx_commit=2 innodb_doublewrite=1 innodb_flush_method=O_DIRECT innodb_max_dirty_pages_pct=80 innodb_file_format=barracuda innodb_file_per_table max_connections=2000 table_cache… to not to penalize further TPS. MySQL 5.6.2 Results Now let’s test MySQL 5.6.2. It is important…
Post: Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
…MySQL manual, especially the option and variable reference table…Flush_commandsblogpercona.commanual flush…
Post: What to tune in MySQL Server after installation
September 29, 2006 By 118 Comments
… which means do not flush log to the disk but only flush it to OS cache. The log is still flushed to the disk… case MySQL Server crashes. Value 2 only cause data loss with full OS crash. table_cache – Opening tables can be expensive. For example MyISAM tables mark MYI header to mark table as currently in use…
Post: Aligning IO on a hard disk RAID – the Benchmarks
June 9, 2011 By 13 Comments
…=/data/mysql socket=/var/run/mysqld/mysqld.sock innodb_file_per_table = true innodb_data_file_path = ibdata1:10M:autoextend innodb_flush_log… table_cache = 2048 max_allowed_packet = 16M binlog_cache_size = 16M max_heap_table_size = 64M thread_cache_size = 32 query_cache_size = 0 tmp_table_size…
Comment: What does Handler_read_rnd mean?
June 25, 2010 By 15 Comments
… row in set (0.00 sec) mysql> flush status; Query OK, 0 rows affected (0.00 sec) mysql> select * from t1; +——+ | n | +——+ | 1… row in set (0.01 sec) mysql> flush query cache; Query OK, 0 rows affected (0.00 sec) mysql> show status like ‘Handler_read… row in set (0.00 sec) mysql> flush tables; Query OK, 0 rows affected (0.00 sec) mysql> select * from t1; +——+ | n | +——+ | 1 | | 2…
Post: MySQL 5.5.8 and Percona Server: being adaptive
December 20, 2010 By 25 Comments
…setting innodb_flush_neighbor_pages=0 , to disable flushing of neighborhood pages (not available in MySQL 5.5.8). The problem with flushing …capacity=500 max_connections=3000 query_cache_size=0 skip-name-resolve table_cache=10000 [mysql] socket=/tmp/mysql.sock (post edited by Fred Linhoss…
Post: Query Profiling with MySQL: Bypassing caches
September 12, 2007 By 6 Comments
… caches? For MySQL Caches you can restart MySQL and this is the only way to clean all of the caches. You can do FLUSH TABLES to clean MySQL table cache (but not Innodb table…
Post: New SpecJAppServer results at MySQL and Sun.
November 12, 2008 By Leave a Comment
…table_cache = 6000 read_rnd_buffer_size = 2M sort_buffer_size = 32k thread_cache = 16 query_cache_size = 0M thread_concurrency = 8 max_heap_table_size=200M log-output = FILE log-slow-queries=/tmp/mysql…xa=0 innodb_flush_method = O_…
