From: Mike Gollub (crankyinmvyahoo.com)
Date: Thu Nov 13 2003 - 20:38:36 CST

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Hi -

I'm running 4.0.13-Max on Linux via PHP. I don't have BDB shared mode set.

I've been experimenting with the BDB transactions and been getting confusing results. My tests
are separate threads running a PHP test script.

It seems that a transaction can acquire 1 or more locks, then fail on a 1213 error (deadlock).
Furthermore, it seems that the deadlock predictor is getting some false positives, so I can get
this result for a non-deadlock lock contention.

My questions are as follows:

1. If a transaction gets a 1213 error while trying to acquire a lock to execute the query, has the
transaction ALREADY been rolled back ?

I'd rather not re-start a transaction if there's a chance the other lock contender could be waited
out (eg: retry the query and wait up to 10 times while getting the same error).

2. If the transaction has in fact been rolled back for me, what's a reasonable transaction retry
policy ?

I'd like ALL the transactions to complete successfully, but I don't want to have to retry a
transaction, say, 100 times.

Thanks.

- Mike.

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