Subject: [Geopriv] LoST synchronous query and referals

From: "Rosen, Brian" <[email-masked]>
Date: Thu, 31 Aug 2006 14:13:18 -0400

I think we all imagine the LoST server to be a synchronous
query/response: from a single port open to the server, you send a query
and wait for the response before sending another query.

Give a little thought to system architecture, where we are expecting all
devices to query LoST periodically (with periodicity in perhaps tens of
hours to days), or when they move out of the region/boundary supplied.
That makes the query load on the server fairly high, but not really too
bad.  Certainly, a synchronous response is still appropriate, with
possibly the server permitting many simultaneous ports open.  We do
expect to see many non-authoritative copies of the authoritative data to
spread load.

Now, suppose there was a bulk querier.  Could be a LIS periodically
revalidating locations for example, but suppose it was the E-CSCF in a
3GPP environment.  I chose that because response time there matters, and
it may very well have more than one outstanding call at a time.

Now, recall that there may be a referral mechanism: you ask a question,
and the local server may not have the answer, but may refer to another
server for resolution.  We don't have details on that.

If the query is actually forwarded by the original server, and the
response comes back through that server, then we do have a problem? A
query could take a long time to complete.  Is that a problem worth
worrying about?  How do we address it?  I'm not asking for an
asynchronous query.  I think that is the wrong direction.  It may be
that the referral is NOT a forward, but a redirect.  That would make the
server not have to wait to respond.

I think a high volume querier could have multiple persistent TCP
connections maintained (if the protocol is TCP based) and choose an
available one as the way to handle the routine cases.  If the server
multithreads, that combination may even work for a long duration query.

Brian

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From: "Rosen, Brian" <[email-masked]>
Date: Thu, 31 Aug 2006 14:22:53 -0400

Sorry again, belongs on ecrit, not geopriv.  I send two messages before
Andy corrected me.

Brian

> -----Original Message-----
> From: Rosen, Brian
> Sent: Thursday, August 31, 2006 2:13 PM
> To: GEOPRIV
> Subject: LoST synchronous query and referals
> 
query/response:
> from a single port open to the server, you send a query and wait for
the
> response before sending another query.