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Re: PropRequestFilter help -- setting up a proxy / more filter questions

From: Yves Lafon <ylafon@w3.org>
Date: Wed, 10 Dec 1997 11:16:45 +0100 (MET)
To: Paul Pazandak <pazandak@OBJS.com>
cc: www-jigsaw@w3.org
Message-ID: <Pine.SOL.3.91.971210104541.27622B-100000@tarantula.inria.fr>
On Tue, 9 Dec 1997, Paul Pazandak wrote:

> >  
> OK, while I didn't see this in the docs, the PropRequestFilters only applywhen the proxy is running.
> The http-server.props file is read when the proxy
> resource is first created, which populates the attributes of the new related resources.
> Any added filter can define attributes (similar to, but different than the mechanism
> used when a resource is defined -- see the CacheFilter for an example). Once installed
> these attributes should be available from Admin/Properties -- each installed filter should
> be listed.
> Fine. Now I have two questions, one on proxies and one on these filters.
> 1) Say that an ingoing filter sets up some threaded processing, or 
> modifies some state
>     that requires some additional work by the outgoing filter. If the 
> request is cancelled
>     before the outgoing filter is called, how can we ensure that at 
> least some clean up routines 
>     are called?

The only possibility to exit before calling the outgoing filter is if the 
request fail. In that case, the exception filter is called (see 
ProxyDispatcher), then you can set the cleaning here.
Or, with this exception filter you can do things to avoid future 
exceptions, and ask for a retry. (this is the do { ... } while (rtry) in 
the perform method of w3c.www.protocol.http.HttpManager)

> 2) Any time I have tried to configure Jigsaw as a proxy Jigsaw chokes at the point of
>     saving the properties...this doesn't occur in NT, only in Win95. The basic sets are:
>     1) create a proxy resource, e.g. called proxy, in the root
>     2) configure it so it's local-root is root
>     3) change the general props so that w3c.jigsaw.root.name is now proxy
>     4) save the properties. (chokes)
>         ...I noticed the via: attribute is growing in size.    I've included a recent dump below.
> Paul.

Hum... the server name is objs-mn-2.visi.com, and you try to access As it doesn't match the server name, it is forwarded to... Then... same process... -> loop...
It eats up all your threads and all your clients, then wait for one which 
is here due to the first read timeout, and so on...
You should access the proxy with its own name, or change it to be the IP 
address (quite ugly as a name!)

      /\          - Yves Lafon - World Wide Web Consortium - 
  /\ /  \                Architecture Domain - Jigsaw
 /  \    \/\    
/    \   /  \   http://www.w3.org/People/Lafon - ylafon@w3.org    
Received on Wednesday, 10 December 1997 05:22:21 UTC

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