Re: [Handle-info] updating resolver cache

[Sean Reilly <sreilly@cnri.reston.va.us>]

Hi Scott,

The proxies don't know about each other sending the ?auth=x request to  
one proxy won't propagate.  The only way I know to refresh a specific  
handle in each the cache for all of the proxies is to send the ?auth=x  
request to each one individually.  I can provide a list of IP  
addresses for the proxies but that still may not reset every proxy  
because three of them are behind a load balancer and not individually  
addressable via http.

The current set of proxies are here
http://sps1.handle.net/<hdl>?auth
http://sps2.handle.net/<hdl>?auth
http://sps3.handle.net/<hdl>?auth
http://sps4.handle.net/<hdl>?auth
http://sps5.handle.net/<hdl>?auth
http://sps6.handle.net/<hdl>?auth
http://ehs4.handle.net/<hdl>?auth
http://cr5.crossref.org/<hdl>?auth


Different combinations of these are responsible for hdl.handle.net and  
dx.doi.org.  I believe the current configuration means that any  
requests going to the sps*.handle.net machines are routed through the  
load balancer so they aren't guaranteed to refresh each individual  
proxy.  This set of proxies also changes on occasion, so I wouldn't  
depend on the above list being the same after six months.

The only way that the handle API would help is if you used it to set  
the TTL for your handles to a low value.  The proxy is just another  
application that sits on top of the handle resolution system.  I would  
say that with the current amount of traffic on the proxies I think  
that your handles will be purged from the cache pretty quickly, unless  
they are extremely popular (as the cache is LRU- as well as TTL- 
based).  I don't think there would be any problem with setting the  
TTLs for the individual values to something like 30 minutes,  
especially if your handle server provides a UDP interface and is quick  
to respond.

Thanks,
Sean


On Mar 24, 2009, at 1:03 AM, Scott Yeadon wrote:

> Hi,
>
> If we are relying on the CNRI handle proxy service for resolution,  
> according to the docs the proxy cache could take up to 24 hours to  
> update in the event of a change to any of the handle values. Is  
> there anything we can do to ensure the proxy pointed to the right  
> resource after an update? For example, (at a clumsy level) if after  
> an update in our LHS we posted a http resolution request to the  
> proxy using the "auth=x" parameter I assume that would update the  
> cache in one of the resolution servers, but would the results of  
> that request be propogated to the other servers which make up the  
> proxy service? If not, is there a way of ensuring accurate  
> resolution after an update (programmatically, e.g. using the handle  
> API)?
>
> Scott.
>
>
> _______________________________________________
> Handle-Info mailing list
> Handle-Info@cnri.reston.va.us
> http://www.handle.net/mailman/listinfo/handle-info


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