From: Simon J Mudd Date: September 30 2008 8:21pm Subject: Re: Replication Stopping (foreign key issue) List-Archive: http://lists.mysql.com/replication/1465 Message-Id: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii jc@stripped ("Jesse") writes: > Replication has come to a halt on my slave machine because of a > foreign key constraint issue. It was attempting to add a child record > for a parent record that is not present. After checking it, starting > with that particular missing parent record, there are no more below > that area. My question is this. If it's present on the master, why > wouldn't it be present on the slave before the child record would have > been added? I did not receive such an error on the master server?? I > could probably add the missing master record, but the problem is that > this will occur again. It's happened about 3 times now. Does anyone > have any suggestions? This is just showing you that the databases that you thought were in synch are not in fact the same. If this is a must (and for most slaves it is) then you need to check the db consistency between the 2 instances and find out what is different and fix it. maatkit has some tools to do this as often it's quite hard on a busy system where the data is changing while you're trying to check for differences. If you can afford downtime it might be easier to take a new copy from the master or another slave (if you have one) which you haven't had these issues on. Replication generally works fine if there are no problems. It also assumes that there are no local changes on the slave which may break replication. Could this be a possibility? Certainly the statements (or transactions) are executed in the same order on the master as on the slave so that shouldn't be an issue, under normal circumstances. Simon