… used when you just start MySQL Server. The rest of memory is available for connections. For exampe with 8GB server you might have everything listed adding up to 6GB, so you have 2GB left for your threads. Each thread connecting to MySQL server… once others, for example tmp_table_size is rather maximum amount of memory MySQL will allocate for this operation. Note it is…
Post: MySQL Connection Timeouts
April 19, 2011 By 4 Comments
… very 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… to increase net.core.somaxconn kernel setting which contains the maximum depth of listen queue allowed. The kernel I’m running…
Post: Percona XtraDB Cluster: Failure Scenarios with only 2 nodes
July 25, 2012 By 6 Comments
… to use the mysql server: [root@percona1 ~]# mysql Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 868 Server version: 5… rows in set (0.00 sec) When the connection is back, the two servers are like independent, these are now two single…:42:51.268 INFO: gcomm: connected 2012-07-24 11:42:51.268 INFO: Changing maximum packet size to 64500, resulting msg…
Post: How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
…_name | Value | +———————————–+———————-+ | Aborted_clients | 205174 | | Aborted_connects | 29 | | Binlog_cache_disk_use | 0…MySQL server are extremely limited, and for serious analysis it’s basically mandatory to use a server…to deliver the maximum value to the …
Post: Configuring MySQL For High Number of Connections per Second
January 6, 2012 By 23 Comments
…connection attempts to be refused. What back_log variable specifies is second parameter to listen() operating system call. The maximum…connections waiting on connection instead of failing quickly and potentially connecting to different server, but that can be fixed by setting the client connect…
Post: Filling the tmp partition with persistent connections
August 6, 2012 By 14 Comments
…connections. The application starts to load data into the database with “LOAD DATA INFILE”. After some minutes the server… RAM, tmpfs and ramfs. Tmpfs has a maximum size, so it returns an error if …most likely killing system in the end. Conclusion MySQL can creates temporary files even thought those …
Post: Percona Server 5.1.49-rel12.0
September 15, 2010 By 6 Comments
… on query cache mutexâ€. (Oleg Tsarev) log_connection_error – Issues the warning “Too many…server. (Yasufumi Kinoshita) Option syslog was added to the mysql server. If enabled, all commands run on the server…. Bug #592007 – More strictly enforces the maximum purge delay defined by innodb_max_…
Post: How much memory can MySQL use in the worst case?
February 12, 2009 By 17 Comments
…_buffer_size + sort_buffer_size)*max_connections“. This was never true — not… And at a minimum, most servers these days need to consider… OK, 0 rows affected (2.34 sec) mysql> select get_lock(@a, 1); +—————–+ | get_lock(@a, …no formula to compute the maximum possible memory usage, and there…
Comment: MySQL 5.5 and MySQL 5.6 default variable values differences
February 21, 2013 By 8 Comments
… past 2M but still a bit too big for the maximum possible speed for OLTP that tends to involve lots of… or using connection settings if that’s not possible. More on this at https://blogs.oracle.com/supportingmysql/entry/mysql_server_5_6_default . thread_cache_size is quite low, and dynamic based on max_connections, just to be…
Post: Apache PHP MySQL and Runaway Scripts
May 20, 2008 By 20 Comments
… at Server-Status I’ve seen scripts executing for hours sometimes which is obviously the problem – they take Apache Slot, MySQL Connection and…: Running “TightLoop” script terminated after 30 seconds with “Fatal error: Maximum execution time of 30 seconds exceeded in /var/www/html…
