The way it's *supposed* to work is you only get notifications for
changes that occur within the collection you specify. I can't recall
actually testing that case, though. Again, I think this part relies on
the notification mechanism to determine which events are relevant, so
the documentation Daniel mentioned might have clues.

-James

On Wed, 2004-12-08 at 10:24 -0800, Warwick Burrows wrote:
> This is exactly what I needed James. Thanks!
> 
> > They should be asynchronous. Daniel Florey wrote the 
> > notification mechanism, so he can confirm, but I'm pretty 
> > sure on this. 
> 
> Daniel, can you confirm that notifications are asynchronous? Or is there a
> write-up on the notifications that I can look at?
> 
> And I have another question on the cluster cache :-) There is a "base-uri"
> parameter that is specified in the configuration. If this is set to "/files"
> will it pick up all changes to objects under /files? For example when a file
> is checked out/in with a new revision will it also notify other slide
> servers of /history path updates that stem from the change even though
> /history isn't specifically configured as the base-uri?
> 
> Thanks,
> Warwick
> 
> 
> > -----Original Message-----
> > From: James Mason [mailto:[EMAIL PROTECTED] 
> > Sent: Tuesday, December 07, 2004 8:40 PM
> > To: Warwick Burrows; Slide Users Mailing List
> > Subject: Re: Cluster cache
> > 
> > 
> > On Tue, 2004-12-07 at 18:10 -0800, Warwick Burrows wrote:
> > > Hi James,
> > >  
> > > I was hoping you could answer some questions about the 
> > cluster cache 
> > > design. We would like to go into production with Slide but doing so 
> > > requires the cluster cache implementation -- or no caching at all 
> > > which is not even an option :-)  We need to know the cluster cache 
> > > mechanics so we can cater for them.
> > >  
> > > - Are the updates (notifications) between servers performed 
> > > synchronously or asynchronously?
> > 
> > They should be asynchronous. Daniel Florey wrote the 
> > notification mechanism, so he can confirm, but I'm pretty 
> > sure on this. When a resource is modified the server sends 
> > notifications to all subscribers that there are events 
> > waiting for them. The subscribers (other servers) then POLL 
> > the server and get a list of changed resources. Each 
> > subscriber then removes the resource in the list from their cache.
> > 
> > > - If an update to a server fails will it be retried?
> > 
> > It depends on where the failure is. If a subscriber is unable 
> > to POLL a server, it will retry. In fact, each subscriber 
> > periodically POLLs the server just to be sure it hasn't 
> > missed any notifications. The POLL frequency should be configurable.
> > 
> > >  
> > > Any other design points I should be aware of?
> > 
> > Not that I can think of.
> > 
> > >  
> > > Incidentally I had mentioned that locks could be an issue with the 
> > > cache design in that two lock requests coming in at the 
> > same time may 
> > > both return with the lock. It isn't an issue for us though 
> > as locking 
> > > is controlled by our DAV applications and the lock information they 
> > > share is stored in a DB. Only one app is guaranteed to get the lock 
> > > and so create a Slide lock. One way to mitigate this 
> > problem for other 
> > > clients may be to allow for the "lockstore" store to be 
> > specifically 
> > > configured so that only lock related metadata isn't cached.
> > 
> > ExtendedStore has five (I think) separate caches. You can set 
> > the size of each cache by setting parameters on the store. 
> > One of the caches is for locks. Take a look at the source for 
> > ExtendedStore, since I'm not sure where, if anywhere, the 
> > parameters are documented.
> > 
> > -James
> > 
> > >  
> > > Thanks,
> > > Warwick
> > >  
> > >  
> > 
> 
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