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Showing posts from April, 2014

java.sql.SQLException: Lock wait timeout exceeded; try restarting transaction

innodb_buffer_pool_size and key_buffer_size MySQL has very limited memory allocation for cache use. If you are using Atmail with MySQL in production, it is imperative you review and optimize MySQL for your hardware and memory. You can increase performance dramatically and reduce I/O usage by tweaking MySQL to use more of your system memory for the cache and buffers. The two easy options for increasing performance for mysql are the  innodb_buffer_pool_size  and key_buffer_size  options. Atmail uses InnoDB tables for the user authentication & log-files, and if you have a large userbase performance can be dramatically improved by increasing the  innodb_buffer_pool_size . Other tables such as the UserSettings, Abook, use the MyISAM table format which uses the  key_buffer_size  option. For a production machine running all the Atmail services with 2GB of RAM we'd recommend the following option: innodb_buffer_pool_size=256M key_buffer_siz...