How to avoid a MySQL deadlock

There are things we could do to eliminate a deadlock after we understand it.

– Make changes to the application. In some cases, you could greatly reduce the frequency of deadlocks by splitting a long transaction into smaller ones, so locks are released sooner. In other cases, the deadlock rises because two transactions touch the same sets of data, either in one or more tables, with different orders. Then change them to access data in the same order, in another word, serialize the access. That way you would have lock wait instead of deadlock when the transactions happen concurrently.

– Make changes to the table schema, such as removing foreign key constraint to detach two tables, or adding indexes to minimize the rows scanned and locked.

– In case of gap locking, you may change transaction isolation level to read committed for the session or transaction to avoid it. But then the binlog format for the session or transaction would have to be ROW or MIXED.

Published by : zahir zainal

Date : 29/10/2014