… 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… look at Prepared_stmt_count to see how many prepared statements are allocated on server and Com_stmt_send_long_data to… away if you close connection. In Percona Server you can do better as you can query temporary tables too: mysql> select sum(data_length…
Post: How FLUSH TABLES WITH READ LOCK works with Innodb Tables
March 23, 2012 By 20 Comments
… WITH READ LOCK to temporary make MySQL read only. In many cases the period for which server has to be made read only… to the server, which in the end causes “field list” operation to be blocked too, which among other tools used by mysql client, so you might get a feel you can’t connect to the…
Post: Too many connections? No problem!
March 23, 2010 By 28 Comments
…? [percona@sandbox msb_5_0_87]$ ./use ERROR 1040 (00000): Too many connections Just happened to one of our customers. Want to know… the server is flooded. So, when this happens in production, the problem is – how do you quickly regain access to mysql server to… to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 8 Server version: 5.0.87-percona-highperf-log MySQL Percona…
Post: How to Monitor MySQL with Percona's Nagios Plugins
February 22, 2012 By 8 Comments
… will alert when a snapshot is failed or overly full. Too many deadlocks. Deadlocks (and lock wait timeouts, covered in another plugin…-check-mysql-status plugin to alert when the server‘s Uptime variable is too small. The server is approaching max_connections. Overflowing the max_connections setting…
Post: What to tune in MySQL Server after installation
September 29, 2006 By 116 Comments
…MySQL Server straight after installation, assuming it was installed with default settings. I’m surprised how many… one does not really affect performance too much, at least on OS with decent…tables (remember each connection needs its own entry) if you have many connections or many tables increase it…
Post: MySQL Server Memory Usage
May 17, 2006 By 18 Comments
…MySQL Server so it uses too small amount of memory it will likey perform suboptimally. If you however configure it so it consumes too…MySQL Server. The rest of memory is available for connections. For exampe with 8GB server… and Cursors. Single connection may have many prepared statements and cursors…
Post: How Percona diagnoses MySQL server stalls
March 3, 2011 By 6 Comments
…many requests for help with server stalls. They come under various … thing to check for. VARIABLE=${VARIABLE:-Threads_connected} You need to change the threshold…and sometimes the problem is doing too much work without blocking. Likewise, …of. There are many things that can cause a stall in MySQL, and …
Post: MySQL Connection Timeouts
April 19, 2011 By 2 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… too low for many conditions. Now lets look more into the problem and do some Math. First lets look into how MySQL accepts connection…
Post: Identifying the load with the help of pt-query-digest and Percona Server
December 29, 2011 By 3 Comments
… analyzed and fixed. And there are not too many tools out there that can make your …Server. Another great thing about Percona Server is the ability to enable logging atomically, not just for new connections as in MySQL…So say if you were using the vanilla MySQL server, you would see an entry like this…
Comment: Too many connections? No problem!
November 21, 2011 By 28 Comments
… our redhat server w/ mysql having “too many connection” problem & it doesn’t work. gdb -p $(cat data/mysql_sandbox5087.pid) -ex “set max_connections=5000″ -batch > gdb -p $17391 -ex “set max_connections=5000″ -batch GNU gdb…
