[Zope] Conflict error

[Brian Sullivan]

On 11/20/06, Maciej Wisniowski <maciej.wisniowski at coig.katowice.pl> wrote:
> > Often I see messages like the following in the event log:
> >
> > 2006-11-20T11:57:33 INFO ZPublisher.Conflict ConflictError at
> > /<***some location***> : database conflict error (oid 0x03a7, class
> > BTrees._OOBTree.OOBTree, serial this txn started with
> > 0x0369ab934257a788 2006-11-20 16:51:15.549000, serial currently
> > committed 0x0369ab9975fb5b99 2006-11-20 16:57:27.652000) (122
> > conflicts (2 unresolved) since startup at Fri Nov 17 16:01:43 2006)
> This specific message is just INFO, so it isn't visible to user, but
> there is a statement abotut "(2 unresolved)" conflicts, and this is
> worse because somebody has seen message about ConflicError.
>
> Errors with OOBTree may be connected with session machinery. We had such
> problems under high load and ZEO. Changing session_resolution_seconds
> value in zope.conf to 300 solved the problem. You may try this but, if I
> remember correctly, it will cause that your sessions timeout may be 300
> secs longer and/or shorter. You may try other values.
> It may be interesting what is <***some location***> too.


It seems always to be the same location (but that is the page that is
always displayed for non adminstrative users so that is no suprise)



>
>
> > I am also seeing the server go into some sort hard crash (actually it
> > doesn't crash just seems to peg the cpu doing something) ...that seems
> > related. (but I am not totally sure). Sometimes it "magically"
> > recovers but more often than not I have to restart the service to get
> > some sense of normality.
> So what is a 'crash' for you?

In this case it just pegs the cpu running the python zope process at near 100%.

> Any errors in event
> log or Zope just doesn't answer for a long time? If the latter thing
> then there is a DeadlockDebugger that shows what is Zope doing, even
> when it is not responsible, but I'm afraid that it won't work under
> Windows, but I've never tried.



I will have a look to see if it provides any information.


>
> > What does this message mean -- should I be worried about it?
> As far as you see only INFO it is nothing bad, but ERROR that
> means conflict error was unresolved is visible to the user, although
> hitting 'Refresh' usually is enough.

It seems that just having the error in info is not a problem but what
I am seeing is that often after an "unresolved" instance my problem
happens.


>
> There you may find some informations (but this is based on zope 2.7):
> http://www.plope.com/Members/dunny/conflicts/view
>

I will look there to see if there is anything that seems relavent.