Re: Lock wait timeout exceeded; try restarting transaction - Simon Garner - com.mysql.lists.cluster

3 messages in com.mysql.lists.clusterRe: Lock wait timeout exceeded; try r...

From	Sent On	Attachments
Simon Garner	20 Jun 2005 20:33
Simon Garner	26 Jun 2005 17:29
Mikael Ronström	27 Jun 2005 00:54

Subject:	Re: Lock wait timeout exceeded; try restarting transaction
From:	Simon Garner (sgar...@expio.co.nz)
Date:	06/26/2005 05:29:03 PM
List:	com.mysql.lists.cluster

Nobody has any ideas about this?

It is happening to me a lot. It appears there are two configuration settings which may help, but I'm not sure what the best values to use are:

http://forums.mysql.com/read.php?25,28082,29118

[NDBD]TransactionInactiveTimeout "If the transaction is currently not performing any queries but is waiting for further user input, this parameter states the maximum time that the user can wait before the transaction is aborted."

I don't see how this one would help.

[NDBD]TransactionDeadlockDetectionTimeout "This timeout parameter states how long the transaction coordinator will wait for query execution by another node before aborting the transaction, and is important for both node failure handling and deadlock detection. Setting it too high can cause a undesirable behavior in situations involving deadlocks and node failure."

This one looks like it could solve the errors if I increase it. But I am concerned about the last sentence which cautions against doing so.

Any recommendations?

-Simon

Hi folks,

We are using MySQL Cluster (4.1.12) for a php web application using 3 nodes.

Intermittently, some queries return the following error:

ERROR 1205 (HY000): Lock wait timeout exceeded; try restarting transaction

We just have to refresh the page and it works. The queries which are failing are single queries, not transaction sets. The tables involved do include TEXT fields, if it makes any difference.

I think this is the same issue reported here: http://bugs.mysql.com/bug.php?id=9045 and http://bugs.mysql.com/bug.php?id=8324

i.e. it sounds like a deadlock is occurring when two users attempt to access the table at once.

Any tips for fixing or working around this?

-Simon