The quickest way to test that I can think of is to be stepping through
the PK generation code in the debugger and after you lock/select the
PKs, use "mysqladmin kill" to kill your connection before the
update/unlock. You can then try to access the auto_pk_support table
from another app (or the mysql prompt) and see if it is still
locked/etc. I might could use my CayenneExample (with a few tweaks) to
test this in a bit.
/dev/mrg
-----Original Message-----
From: Andrus Adamchik [mailto:andru..bjectstyle.org]
Sent: Thursday, July 13, 2006 11:23 AM
To: cayenne-use..ncubator.apache.org
Subject: Re: Duplicate Key Problem
On Jul 13, 2006, at 10:57 AM, Gentry, Michael ((Contractor)) wrote:
> Is the PK cache per VM or per DataNode? I was thinking per DataNode
> (obviously within the same VM, of course).
True, more accurately it is one per DataNode, and is shared by all
DataContexts that sit on top of a given DataDomain.
> Another thing that could be tricky is that the MySQL JDBC connector
> (Connector/J) has an autoReconnect=true option, which would catch a
> disconnection before Cayenne could see it and reconnect. Not sure at
> all what would happen to an in-progress transaction if that were the
> case.
Good point. But I am more concerned about runtime exceptions in the
code that theoretically can cause a PK range to become invalid. One
straightforward way to fix that is to apply the same approach we did
for Sybase PK generator per CAY-588 (i.e. ensure that PK is generated
outside of the main transaction. I guess that's what we'll have to
do, but I want to have a way to reproduce the problem first, if only
to know that our fix actually fixes it.
Andrus
This archive was generated by hypermail 2.0.0 : Thu Jul 13 2006 - 11:44:51 EDT