Logging question/suggestion

[KevinBenson]

Yep that is essentially what I was thinking something like a simple 
callback or polling mechanism.  The UWS spec does specify what are the 
interface methods namely createJob, startJob, resumeJob, destroy, and 
GetResourceProperty(for polling); so a client could easily interface 
with this UWS and be able to call and poll the "job" which in this case 
is some logging query that eventually goes to vospace.  Though I have 
not really thought about the JDL much in this scenario.

Yep e-mail might still be nice granted I would rather see this 
machine/automated client that kicks off a bunch of logging 
request/queries for harvest to all the many VO services give me "one" 
nice e-mail that said here are the services that succeeded, here are the 
ones that failed, and here is a URL to a really nice constructed graph 
of all the VO activity :)    versus the potential of a single e-mail 
from each of the logging services.  Unfortunately I think you could only 
recommend that idea for clients not require it.

cheers,
Kevin

Eric Saunders wrote:
> Hi Kevin
>
> What you describe sounds to me like a simple callback mechanism. I 
> think it's a good idea. As you say, it allows the client to 
> dynamically poll the logging-enabled service for status information, 
> which may be important if the client wishes to initiate other jobs or 
> services which are strongly dependent on the state of that service. 
> However, I think it may still be a good idea to send an explicit 
> confirmation message from the service if/when processing is complete, 
> for example.
>
> With regard to the 'UWS pattern' - as I understand it, this is simply 
> an OO Factory pattern. Whether you choose to implement the logging 
> service using a factory or through some other mechanism (e.g. a single 
> collection or aggregate object representing the service) should make 
> no difference to the external interface seen by the client. As far as 
> the client is concerned, it makes a job request, receives a unique id 
> which it uses to check on the status of the job... and that's all it 
> knows, or cares.
>
> Cheers
>
> Eric
>
> ---------------------------------------
> Eric Saunders
> eSTAR Project (http://www.estar.org.uk)
> Astrophysics Group
> University of Exeter
>
>
>
> On Thu, 25 May 2006, KevinBenson wrote:
>
>> On the last day of the IVOA meeting me and Guy Rixon were chatting 
>> about the Logging and namely how it will need to do e-mail and how 
>> users will check e-mails to see when it is complete or if an error 
>> occurred.  And if your a machine client you will need to monitor 
>> e-mail and/or VOSpace to see when things are complete or error to do 
>> things more automated.  Also possibility of e-mail systems being down 
>> even though rare could be a small/minor problem.
>>
>> A suggestion was made; how about implement the UWS pattern with 
>> Logging. What do others think about it?
>> It would mean that clients could do polling to see if a job is 
>> complete or error happened, and possibly resume jobs if there was a 
>> problem.  It might seem a little heavy weight, but since we agreed we 
>> need security, vospace, handle long running queries, and a requestid 
>> which matches the resource identifier it would seem UWS idea might be 
>> a good fit.  Plus it is quite likely that libraries to handle UWS 
>> will incorporate the security and vospace.
>>
>> cheers,
>> Kevin
>>