…wait time between tries for all operations are configurable. Also, we removed –lock-wait-timeout which set innodb_lock_wait…connection over the web, else it will use a standard (http) connection. pt-stalk and pt-mysql-summary have built-in MySQL….2 for MySQL is an exciting release with many new and …
Post: Modeling MySQL Capacity by Measuring Resource Consumptions
March 8, 2011 By 1 Comment
…growths. In many cases however…for MySQL process: root@ubuntu:/var/log/mysql# …TOTAL_CONNECTIONS: 1 CONCURRENT_CONNECTIONS: 0 CONNECTED_TIME: 800 BUSY_TIME: 775 CPU_TIME:…TIME” here, subtracting CPU time from it we get “Wait Time” which is in this case 775-49=726 seconds or 4005us per select. Wait time…
Post: Implications of Metadata Locking Changes in MySQL 5.5
February 1, 2013 By 9 Comments
… you can see how the query spent nearly all its time waiting in the “Opening tables” state. Now this behavior with respect… stall as many threads can get piled up waiting for table metadata lock bringing down the MySQL server or causing all the connections to get depleted. There are some other interesting consequences as well for application that use MySQL…
Post: MySQL 5.5 and MySQL 5.6 default variable values differences
February 21, 2013 By 8 Comments
…OFF | | PERFORMANCE_SCHEMA_EVENTS_WAITS_HISTORY_SIZE | 10 | 5 | | PERFORMANCE_SCHEMA_EVENTS_WAITS_HISTORY_LONG_SIZE | …MySQL 5.6 goes – STRICT_MODE and other safer behaviors are not enabled by default. innodb_old_blocks_time… change to help workloads with many connects/disconnects sync_relay_log_info…
Post: MySQL Connection Timeouts
April 19, 2011 By 4 Comments
…MySQL server you will see sporadic connection timeouts, such as Can’t connect to MySQL server on ‘mydb’ (110). If you have connects timed…connections pretty quickly, however if it stalls waiting…
Post: Configuring MySQL For High Number of Connections per Second
January 6, 2012 By 23 Comments
…connections to MySQL per second during peak times. This is a high number by any account. When a new connection to MySQL…many connections per second is thread_cache which impacts cost of connections…
Post: Announcing Percona Live MySQL Conference and Expo 2012
August 9, 2011 By 11 Comments
…MySQL community has been waiting to see if there will be a MySQL…and leading events worldwide several times each year. But a…connections. We can make this a success. (It helps that we’ve brought in the people who ran the very first MySQL…fans (and financial supporters) of many of their conferences. The…
Post: Are PHP persistent connections evil ?
November 12, 2006 By 32 Comments
… of connections you need. The problem is there can be only so many connections active between Host “Apache” and Host “MySQL“: Port 3306 as connection…’t be recycled instantly and have to spend some time in “FIN” stage waiting before they can be recycled. On Linux you… too many MySQL server connections. Some people simply do not realize you can increase max_connections variable and get over 100 concurrent connections with MySQL others…
Post: How to Monitor MySQL with Percona's Nagios Plugins
February 22, 2012 By 11 Comments
… a snapshot is failed or overly full. Too many deadlocks. Deadlocks (and lock wait timeouts, covered in another plugin) are frequent causes…-check-mysql-status plugin can be configured to alert when Threads_connected approaches max_connections too closely, which can give the system administrator time…
Post: How to debug long-running transactions in MySQL
March 8, 2011 By 6 Comments
…if the disk has less than this many MB free. MB_THRESHOLD=100 # Make… host=$(mysql -ss -e ‘SELECT p.HOST FROM information_schema.innodb_lock_waits w… has worked for me a few times. Alas, there are some cases where…your server to find idle-in-transaction connections that are just sitting there doing …
