[Zope] Integrating Zope with Excel.

[Chris Withers]

Paul Winkler wrote:

> 1) an External Method was making an http request using httplib
> to a host that had become (wrongly) firewalled.
> I don't know how this could completely block zope, but that
> was the behavior I observed. A bit of using gcc as described
> in the "Debug a Spinning Zope" article helped me identify
> the ext. method in question and rewrite it so it can't
> possibly block like that.

This sounds like something that should be discussed on zope-dev, but if 
it comes down to something C-ish blocking python's thread stuff, then ti 
may even end up on python-dev...

> 2) When using ZEO with an inadequate client cache, it is possible
> to end up with zope apparently doing nothing but waiting for ZEO
> while the cache thrashes.  This  happened to us when somebody
> was downloading a very large file (more than twice the size of the
> client cache).  A look at the event logs showed a long stream of ZEO client 
> cache flip messages during the time in question.  
> We drastically increased the size of the client cache and haven't had 
> that problem since.
> I think that in this case, zope was still servicing requests, it
> was just doing so extremely slowly.  When the download finished,
> everything instantly cleared right up.

Yeah, ZEO's storage server is currently single threaded, so it can cause 
problems if abused...

cheers,

Chris

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