…MySQL to determine when it’s not responsive? A: The easiest way to do this is to simply connect to it and attempt to run a…a large number of long-running queries in the output of SHOW PROCESSLIST that might be a sign that trouble is…
Post: Replication in MySQL 5.6: GTIDs benefits and limitations - Part 2
May 30, 2013 By 6 Comments
…a try! # For s0,s1, s3, s4 mysql> stop slave; mysql> change master to master_port=10002; mysql> start slave; # And then check the number…MySQL Utilities (this will be the topic of a future post). Unfortunately, this will not work for every use case, and until this is fixed, it is…
Post: Is Synchronous Replication right for your app?
May 14, 2013 By 18 Comments
…a crash, it has to get to disk. This has no effect on standard MySQL replication from this instance, since MySQL replication is…this variable (default is 1 retry). This means more waiting, and after the limit is exceeded you will still get the deadlock error. This is not…
Post: 10 years of MySQL User Conferences
April 11, 2013 By 6 Comments
…a fun place to visit though it attracted a smaller crowd and this is…MySQL Management. Monty is working on the Maria storage engine to replace Innodb for a number…MySQL 5.1.46 is GA and MySQL 5.5.4 is not GA at the time of the conference. 2011 The conference is…
Post: Understanding the maximum number of columns in a MySQL table
April 8, 2013 By 5 Comments
… MySQL, we’ll see that it’s defined as 4096. This, however, is not the true limit. To find out what the actual limit is… message you get is not very interesting and just says “Can’t create table ‘test.t’ (errno: 139)”. This is because InnoDB has a hard limit… $sql; So the maximum number of columns for a table in MySQL is somewhere between 191 and 2829, depending on a number of factors. I’d…
Comment: SimCity outages, traffic control and Thread Pool for MySQL
March 21, 2013 By 16 Comments
…numbers of database connections the thread pool supported. I was not…not happen, so now by saying this I will have started a likely flame war discussion. The purpose behind the feature is…
Post: Aligning IO on a hard disk RAID – the Theory
June 9, 2011 By 18 Comments
…goal is to write and read as little as possible. If you gonna be writing small (say 500…a start sector, instead use the next number that divides by the number of sectors in a stripe element without a… without a reminder. Lastly, if this is not a system boot disk you are working on, you may not need …
Post: How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
…number and the cache size, etc. What else is important is the ‘lm’ flag, which tells me this is a 64-bit CPU. From this…This is happening 6 times every ten seconds. We need to figure out what is happening because it can indicate something else is wrong. This is not a…
Post: Be productive with the MySQL command line
December 21, 2012 By 14 Comments
… paginate results, which is very handy. But this is not the way the…a good size for you InnoDB redo logs: the estimation is based on the variation of the Log Sequence Number during a…name=’Music’; and let’s say you want to change …a copy of your session. Conclusion The mysql command line client is not …
Post: What's the recommended MySQL version?
August 15, 2011 By 24 Comments
…but this is the biggest distinguisher). For an existing MySQL database server, I’d encourage not jumping on a new …then consider it. The reason I say this is that the previous version is going to be maintained quite … to skip a version if I can. A fair number of our customers are still running MySQL 5…
