…How do you monitor MySQL to determine when it’s not responsive? A: The easiest way to do this is to simply connect to…mysql_install_db under strace, I saw that it was getting a lot of “bad file descriptor” errors. I was able to get…
Post: Is your MySQL buffer pool warm? Make it sweat!
April 16, 2013 By 6 Comments
…, by mysql_slowlogd. This daemon is similar to running `tail -f slow.log`, except that it knows how to follow the log stream across log rotation events… later to get these features. Be aware that playback output is really verbose, in production, most likely you want it to redirect to /dev…
Post: Is Synchronous Replication right for your app?
May 14, 2013 By 18 Comments
…to the redo log by default, so applying Callaghan’s law to single-server Innodb, we’d get…to persist after a crash, it has to get to disk. This has no effect on standard MySQL replication from this instance, since MySQL… count + 1 where achievement = ‘killed_troll’; How many players might accomplish …
Post: MySQL and Percona Server in LinkBench benchmark
May 8, 2013 By 18 Comments
…how to setup and run this benchmark, can be found here. We decided to run this benchmark for MySQL…buf_pool_t*, unsigned long) | buf_LRU_get_free_block(buf_pool_t*) | | | |–94.84…how to run benchmark: [mysqld] user=root port=3306 innodb_buffer_pool_size = 30G innodb_flush_method = O_DIRECT innodb_log…
Post: Disconnecting a replication slave is easier with MySQL 5.5+ (RESET SLAVE vs. RESET SLAVE ALL)
April 17, 2013 By 2 Comments
… get writes from the old master, which can cause all kinds of data corruption. MySQL …MySQL versions and it’s easy to shoot yourself in the foot if you use it incorrectly. So how…Log_File: Read_Master_Log_Pos: 4 Relay_Log_File: mysql_sandbox35302-relay-bin.000001 Relay_Log_Pos: 4 Relay_Master_Log…
Post: How to create/restore a slave using GTID replication in MySQL 5.6
February 8, 2013 By 7 Comments
…is GTID and how it works internally because there are many documents about that: http://dev.mysql.com/doc/…GTID. How to set up a new slave The first thing that we need to know is that now Binary Logs …and the binary logs from the master have been purged. This is the error we are going to get: Slave_…
Post: Modeling MySQL Capacity by Measuring Resource Consumptions
March 8, 2011 By 1 Comment
… About Performance by Cary Millsap. So how we can use this data to estimate capacity of MySQL system ? We can look at CPU…_os_log_fsyncs for your disk IO estimation. When you can divide it per number of “Questions” or “Com_select” to get amount… a lot. How to get CPU consumption per query ? You can take a look at procfs for MySQL process: root@ubuntu:/var/log/mysql# cat /proc…
Post: How to Monitor MySQL with Percona's Nagios Plugins
February 22, 2012 By 11 Comments
… up for alerts. Recently I spoke to one person who gets about thirty thousand alerts per week … to delete one of MySQL‘s log or data files from disk. The database server will continue to function,…server has been restarted recently. It is surprising how often a server crashes, perhaps even cycling …
Post: How to recover a single InnoDB table from a Full Backup
January 25, 2012 By 10 Comments
… be focus on how to recover a single tablespace using stock MySQL server. First, you must meet certain prerequisites to be able to restore a…. Then, our first step is to get a consistent backup. First we need to copy all the data to an output directory: The –export… –export /tmp/ Then apply the logs to get a consistent backup: # innobackupex –defaults-file=/etc/my.cnf –apply-log –export /tmp/2012-01-22…
Post: How Percona diagnoses MySQL server stalls
March 3, 2011 By 6 Comments
…. Finally, make sure that the script can log into MySQL (if necessary, put a password into .my…. If I get a few spare hours, I will put together some screencasts illustrating how to use these…our MySQL video/screencast blog site. Another interesting topic is how to examine a system that appears to be …
