…. Now let’s come to the MySQL configuration. MySQL Configuration I used Percona Server 5.5…._io_capacity = 800 innodb_read_io_threads = 8 innodb_write_io_threads = 4 innodb_file_per_table = 1 … of iiBench simultaneously to simulate 5 concurrent connections writing to the table, with each instance …
Post: Introducing the pmp-check-mysql-status Nagios Plugin
March 29, 2012 By Leave a Comment
… of status counters and variables. This is the pmp-check-mysql-status plugin, which can perform computations on status variables. By… small, indicating the server has been restarted Check whether Threads_connected is approaching max_connections, which can be inconvenient to solve in some…
Post: Troubleshooting MySQL Memory Usage
March 21, 2012 By 3 Comments
…max_packet_size per connection) are all connection buffers and so if you close connection MySQL can clean them up. Killing connections (or stopping … Lock system 318875832 (318747272 + 128560) Recovery system 0 (0 + 0) Threads 425080 (406936 + 18144) Dictionary memory allocated 2623331 Buffer pool …
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…/mysql-slow-queries.log long_query_time=15 log-queries-not-using-indexes query_cache_type=1 query_cache_size=32M thread…
Post: MySQL Limitations Part 4: One thread per connection
October 27, 2010 By 14 Comments
… limiting MySQL in core use cases (links: part 1, 2, 3). This post is about the way MySQL handles connections, allocating one thread per connection to the server. MySQL is a single process with multiple threads. Not all databases…
Post: MySQL Connection Timeouts
April 19, 2011 By 2 Comments
… look into how MySQL accepts connection. There is single main thread which is accepting connections coming to LISTEN sockets. Once there is connection coming it… connection and create a new thread or take one out of the thread cache. From this point on MySQL processes network communication in multiple threads…
Post: Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
…MySQL…commanual connect_…thread_cache_sizeblogpercona.commanual thread_concurrencyblogpercona.commanual thread_handlingblogpercona.commanual thread_stackblogpercona.commanual Threads_cachedblogpercona.commanual Threads_connectedblogpercona.commanual Threads_createdblogpercona.commanual Threads…
Post: How Percona diagnoses MySQL server stalls
March 3, 2011 By 6 Comments
… I work on show up as abnormally high values of Threads_connected or Threads_running. That’s a good place to start for… check for. VARIABLE=${VARIABLE:-Threads_connected} You need to change the threshold to 15, and the variable to Threads_running. Check the other…. There are many things that can cause a stall in MySQL, and they usually begin microscopically and get worse over time…
Post: How to debug long-running transactions in MySQL
March 8, 2011 By 6 Comments
…-plugin InnoDB versions, you can’t reliably figure out what connection is to blame for blocking others. You can guess, and…_id INNER JOIN information_schema.processlist p on b.trx_mysql_thread_id = p.ID LIMIT 1′) if [ "${host}" ]; then echo “Host… iterations. And watch your server to find idle-in-transaction connections that are just sitting there doing nothing, and kill them…
Post: How to Monitor MySQL with Percona's Nagios Plugins
February 22, 2012 By 8 Comments
…-check-mysql-status plugin to alert when the server’s Uptime variable is too small. The server is approaching max_connections. Overflowing… error appropriately. The pmp-check-mysql-status plugin can be configured to alert when Threads_connected approaches max_connections too closely, which can give…
