…, key_buffer_size etc, you have reasonable amount of connections but yet MySQL takes much more memory than you would expect, causing… max_packet_size per connection) are all connection buffers and so if you close connection MySQL can clean them up. Killing connections (or stopping related… good tools to detect memory leaks like valgrind are too slow to run in production. So the best thing to do…
Comment: Too many connections? No problem!
March 15, 2012 By 28 Comments
… my website develop in PHP with MYSQL, these are MYSQL values: datadir=/data/mysql socket=/data/mysql/mysql.sock max_connections = 600 wait_timeout = 60 interactive_timeout=1800 skip-name-resolve skip-bdb default-time-zone=America/Caracas log-slow…
Post: Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
… MySQL manual, especially the option …commanual concurrent_insertblogpercona.commanual connect_timeoutblogpercona.commanual Connectionsblogpercona….Slow_launch_threadsblogpercona.commanual slow_launch_timeblogpercona.commanual Slow_queriesblogpercona.commanual slow_query_logblogpercona.commanual slow…
Post: Scaling problems still exist in MySQL 5.5 and Percona Server 5.5
May 20, 2011 By 11 Comments
…,btr_search_build_page_hash_index,btr_search_info_update_slow,btr_search_info_update,btr_cur_search_to_nth_level…,mysql_select,handle_select,execute_sqlcom_select,mysql_execute_command,my sql_parse,dispatch_command,do_command,do_handle_one_connection,handle_one_connection…,JOIN::exec,mysql_select,handle_select,execu te_sqlcom_select,mysql_execute_command,mysql_parse,dispatch_command,do_command,do_handle_one_connection,handle…
Post: MySQL Connection Timeouts
April 19, 2011 By 2 Comments
… busy MySQL server you will see sporadic connection timeouts, such as Can’t connect to MySQL server on ‘mydb’ (110). If you have connects timed in your application you will see some successful connections taking well over the second. The problem may start very slow…
Post: Modeling MySQL Capacity by Measuring Resource Consumptions
March 8, 2011 By 1 Comment
… a look at procfs for MySQL process: root@ubuntu:/var/log/mysql# cat /proc/19018/stat … 1. row *************************** USER:user TOTAL_CONNECTIONS: 1 CONCURRENT_CONNECTIONS: 0 CONNECTED_TIME: 800 BUSY_TIME: 775 CPU…Server, enabled full query logging and log_slow_verbosity=full you can also get …
Post: Getting MySQL Core file on Linux
August 26, 2011 By 1 Comment
…/libc.so.6(__poll+0×53)[0x7fbb86066f93] /usr/sbin/mysqld(_Z26handle_connections_socketsv+0×124)[0x51ba64] /usr/sbin/mysqld(_Z11mysqld_mainiPPc+0xcfc)[0x521b0c… in many cases could be to connect as “gdb -p `pidof mysqld`” select “continue” and let MySQL run. If it crashes you… if you expect to do any MySQL profiling or dealing with crashes. It does not slow MySQL performance yet it is very helpful…
Post: Multiple purge threads in Percona Server 5.1.56 and MySQL 5.6.2
May 3, 2011 By 13 Comments
… innodb_file_format=barracuda innodb_file_per_table max_connections=2000 table_cache=2000 Percona Server 5.1 Results… not to penalize further TPS. MySQL 5.6.2 Results Now let’s test MySQL 5.6.2. It is… with the change are not effective enough: they only slow the growth of the history list. But, TPS in…
Post: Estimating Replication Capacity
July 20, 2010 By 4 Comments
…: mk-query-digest slow-log –filter ‘($event->{user} || “”) =~ m/[…with a lot of connections mysql> show processlist; +——–+————-+———–+——+———+——+———————————————————————–+——————+ | Id | User | Host | db | …
Comment: Debugging sleeping connections with MySQL
May 20, 2009 By 28 Comments
… requests increase 2. mysql queries increase 3. mysql slow queries increase 4. apache connections start to wait on slow mysql queries 5. apache connections take longer to… a connection to the database only when the first query occurs – e.g: function query ($query) { if (!mysql_connection) mysql_connect(); return mysql_query(); } – Reduce slow queries…
