On 7/11/01 3:02 pm, "Paul Zwarts" <paz@oratrix.com> wrote:
Hi all,
As a suggestion for Solaris users (Im on linux) please be sure to check that your PYTHON thread is the culprit and NOT the database thread. They are indeed two separate issues. Why I say this is because I don't know much about Solaris, but on Redhat linux (kernel 2.4+) a ps -ef command returns the status of the database thread.
Good point Paul - thing is, this threading issue occurs without using a database adaptor. The original post used some standard DTML that did a Catalog search to demonstrate the problem. A different version of the DTML method used a ._range() construct to do much the same thing.
What we experienced months ago was the very same issue. (as per this thread in its history). We had thought that python was the culprit (we used to be on Irix 6.5 which doesn't feedbak thread status). What it turned out to be was UPDATE WAITING or COMMIT WAITING was appended to the thread. Not python at all, but the database driver. When a stalled thread ocurrs, zope stalls because its waiting for the thread to close. This action is required because it supports the required sql locking schema. Otherwise you get ancient problems of updates impinging on updates causing bad data integrity.
That would certainly make sense.
We had never experienced crashes, related directly to this, but we have had crashes. That at first made me think of this same problem, but then watching activity in the manage_interface/control_panel/debug/refresh+1second showed me a python process in a loop that caused the crash. That culprit was entirely bad programming practice on my part.
Thing is, if you try that on Solaris, you get nowhere, as the python process in a loop grabs the only thread you've got! :)
I don't know if this blurb helps anyone, but I hope I can cause some ideas to occur per narrowing down the possibilities.
I think that ideas are about the only thing that is driving this forward at the moment, well, everything *I've* tried has got me nowhere so far. I'm getting totally exasperated with this, is this the right list to be even discussing this I wonder, zope-dev maybe?
It may also be worth noting that we still run zope 2.3.3 to this date because python2 just seems simply to be slower. Perhaps this weekend I'll take a second stab at building a test server on python2 and the latest zope. If I learn anything more, I'll update...
Cheers, Paul Zwarts
That'd be great. Thanks for the thoughts, Tone. -- Dr Tony McDonald, Assistant Director, FMCC, http://www.fmcc.org.uk/ The Medical School, Newcastle University Tel: +44 191 243 6140 A Zope list for UK HE/FE http://www.fmcc.org.uk/mailman/listinfo/zope