How to detect deadlocks in Mysql / innodb ?

Question

Hi,

I know that deadlocks occur inevitably when using transactions in Innodb and that they are harmless if they are treated properly by the application code - "just try it again", as the manual says.

So I was wondering - how do you detect deadlocks? Does a deadlock issue some special mysql error number? I am using PHP's mysqli extension if that matters.

Thank you.

Edit: solution found, see comments

Answer 1

Try MaatKit. It has a deadlock logger.

Answer 2

http://dev.mysql.com/doc/refman/5.0/en/innodb-error-codes.html

1213 (ER_LOCK_DEADLOCK)

Transaction deadlock. You should rerun the transaction.

Answer 3

Try innotop, will detect the deadlock for you.