[ZODB-Dev] Errors running a Stress Test

[Tim Peters]

[Brandon Ehle]
> I've used ZODB w/ ZEO in the past, and I wrote a quick stress test to
> try and test for bugs that I've encountered in the past.  I'm
> currently running into lots of bugs that I haven't seen before,

You showed exactly two tracebacks later, one on the server and one on the
client.  How does that relate to "lots"?  For example, you have many
instances of these same two tracebacks?  You have many distinct tracebacks,
but tired of collecting them?  Something else?

> so perhaps I'm doing something wrong that I didn't notice, but I was
> curious if anyone else was seeing these problems.

We've gotten little feedback on 3.3a2 so far, and (of course) it is an alpha
release.  Thanks for testing it!

> After running for a couple hours I got all sorts of errors.  Am I
> doing something obviously wrong, or am I just tickling ZODB in the
> wrong way?

They're probably bugs.  *Starting* the database isn't robust:

>     conn = db.open()
>     if 'test' not in conn.root():
>         conn.root()['test'] = OOBTree()
>         get_transaction().commit()

because when you first run it, all the threads may try to create the root's
'test' simultaneously.  Indeed, that's what happened when I first tried it,
leaving only one thread surviving to continue beyond that point.  The rest
looked fine to me, though.

> ***** Client side errors
> ...
>   File "C:\Python23\Lib\site-packages\ZEO\cache.py", line 725, in
>     _makeroom size, e = self.filemap.pop(ofs)
> KeyError: 301258

Probably a bug in the new ZEO client cache.


> ***** Server side errors
>
> 2004-03-15T11:46:52 ERROR(200) Conflict Resolution Unexpected error
> Traceback (most recent call last):
>   File "C:\Python23\Lib\site-packages\ZODB\ConflictResolution.py",
> line 108, in tryToResolveConflict
>     old = state(self, oid, oldSerial, prfactory)
>   File "C:\Python23\Lib\site-packages\ZODB\ConflictResolution.py",
> line 38, in state
>     p = p or self.loadSerial(oid, serial)
>   File
> "C:\Python23\Lib\site-packages\ZODB\FileStorage\FileStorage.py", line
>     581, in loadSerial raise POSKeyError(oid)
> POSKeyError: 0000000000000001

Probably some other bug <wink>.

> Win2K SP4
> Python-2.3.3
> ZODB-3.3a2

If you can, try running from current CVS HEAD of the ZODB module.  Bugs have
certainly been fixed since 3.3a2 was released, although it would take more
time than I've got to guess whether they account for your symptoms.

I've been running your test for about half an hour now on ZODB HEAD without
incident, but with server and clients all on a single machine (that's all I
can get at now), also on Windows.

Oops!  I saw one akin to your server-side traceback whiz by while typing
that.  Nothing odd on the clients yet.