MySQL 5.6 is GA! Now we have new things to play with and in my personal opinion the most interesting one is the new Global Transaction ID (GTID) support in replication. This post is not an explanation of what is GTID and how it works internally because there are many documents about that: http://dev.mysql.com/doc/refman/5.6/en/replication-gtids-concepts.html One [...]
Beware the Innodb Table Monitor
As I stated in my last post, I decided to use the Innodb Table monitor to diagnose an Index count mismatch error a customers found in their mysqld.err log to verify if the problem still existed. The Innodb Table Monitor has existed for basically forever in Innodb (the MySQL manual discusses it back in the 4.1 [...]
More on MySQL Error Messages
I wrote about MySQL Error Messages before and as you might guess I’m not very happy with quality for error messages it produces. Now I’m revisiting this subject with couple of more annoying examples I ran into during last couple of days.
1 2 | mysql> drop database test; ERROR 1010 (HY000): Error dropping database (can't rmdir './test/', errno: 17) |
Rare evil MySQL Bug
There is the rare bug which I ran into every so often. Last time I’ve seen it about 3 years ago on MySQL 4.1 and I hoped it is long fixed since… but it looks like it is not. I now get to see MySQL 5.4.2 in the funny state. When you see bug happening [...]
A quest for the full InnoDB status
When running InnoDB you are able to dig into the engine internals, look at various gauges and counters, see past deadlocks and the list of all open transactions. This is in your reach with one simple command —
1 | SHOW ENGINE InnoDB STATUS |
. On most occasions it works beautifully. The problems appear when you have a large spike in [...]
Troubleshooting Relay Log Corruption in MySQL
Have you ever seen the replication stopped with message like this: Last_Error: Could not parse relay log event entry. The possible reasons are: the master’s binary log is corrupted (you can check this by running ‘mysqlbinlog’ on the binary log), the slave’s relay log is corrupted (you can check this by running ‘mysqlbinlog’ on the [...]
MySQL Stored Procedures problems and use practices
To be honest I’m not a big fan of Stored Procedures, At least not in the form they are currently implemented in MySQL 5.0 Only SQL as a Language Which is ancient ugly for algorithmic programming and slow. It is also forces you to use a lot of foreign constructs to “original” MySQL style – [...]
MySQL Crash Recovery
MySQL is known for its stability but as any other application it has bugs so it may crash sometime. Also operation system may be flawed, hardware has problems or simply power can go down which all mean similar things – MySQL Shutdown is unexpected and there could be various inconsistences. And this is not only [...]

