[ZODB-Dev] My turn for ReadConflictErrors...

[Wankyu Choi]

>> Could I get round them by, for example, putting a RAMCacheManager in 
>> that caches the results of the python script that drives the ZPT?

>yes, or cache the ZPT output. Or put it in a seperate request (iframe, 
>external script, etc) and let the http-level caches handle it. 

I had similar experience and tried RAM Cache Manager, which certainly helped
relieve the problem. Plus, the overall performance shot up ( I have RAM to
burn...4G  :-)

But cached ZPT outputs started to create more problems than they solve:
updating CMF documents, for example, took a way while to make the
corresponding cache expire.

I finally gave up on RCM and is living with sometimes-unbearable
readconflicterrors.

> I wouldnt bother unless you are getting very many of them. It might have 
> "Error" in its name, but ReadConflictErrors are not necessarily bad.

Yes, mostly. You know how I run ZEO and a couple of clients behind Squid ;-)
Guess I'm fighting uphill battles with this setup. 

Squid's false alarm of detecting dead parents every night, too many
readconflicterrors with no apparent heavy traffic, etc. 

Recently I had a visitor who was apparently trying to download the whole
contents of a site I'm running for hours (using Teleport or something like
that), which took.the performance of the site to a crawl for as many hours:
a readconflicterror on every request ( one or two errors per second, that
was too much.)

I thought I could grin and bear anything Zope throws at me.... but this
conflict error thing is too much and makes me worry if I chose a right path
with Zope + ZEO.

The first time I saw that "Site Error (ReadConflictError)" screen of
death... I was the only one using the system on a dev machine (one of the
two desktops I'm using for development; that is, the system wasn't even
connected to the Net) with stock Zope + CMF + Plone. I thought it was just
the odds and didn't worry about it much. 

Now I'm damn worried.

I was pretty sure I'd face a lot of things unexpected when I first took on
the Zope stuff, but didn't expect this many.

Hope this ReadConflictError thing wouldn't be the last straw that'd break my
back.

Just rambling out of frustration :-&

Best wishes,
Wankyu Choi
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  Wankyu Choi
  CEO/President
  NeoQuest Communications, Inc.
  http://www.zoper.net
  http://www.neoboard.net
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