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From Sachith Withana <swsach...@gmail.com>
Subject Re: Orchestration Component implementation review
Date Fri, 17 Jan 2014 16:25:06 GMT
Thanks Saminda for this informative review.

In the case of the multi-threaded vs Single Threaded, where should we have
the synchronization enforced?
To my knowledge, the NewJobWorkers( Getting new Jobs and submitting them)
and the HangedJobWorkers are accessing the Orchestrator table to select the
new and hanged jobs.
Right now, the NewJobworkers are getting all the accepted jobs at once.
it's not focussed on one experiment.

We need to reflect the changes in the Gfac job Statuses in the Orchestrator
table as well. So every time the status of a job change through the Gfac,
it will be accessing the Orchestrator table as well. ( I've sent an email
previously describing the scenario)





On Fri, Jan 17, 2014 at 10:32 AM, Saminda Wijeratne <samindaw@gmail.com>wrote:

> Following are few thoughts I had during my review of the component,
>
> *Multi-threaded vs single threaded*
> If we are going to have multi-threaded job submission the implementation
> should work on handling race conditions. Essentially JobSubmitter should be
> able to "lock" an experiment request before continuing processing that
> request so that other JobSubmitters accessing the experiment requests a the
> same time would skip it.
>
> *Orchestrator service*
> We might want to think of the possibility in future where we will be
> having multiple deployments of an Airavata service. This could particularly
> be true for SciGaP. We may have to think how some of the internal data
> structures/SPIs should be updated to accomodate such requirements in future.
>
> *Orchestrator Component configurations*
> I see alot of places where the orchestrator can have configurations. I
> think its too early finalize them, but I think we can start refactoring
> them out perhaps to the airavata-server.properties. I'm also seeing the
> orchestrator is now hardcoded to use default/admin gateway and username. I
> think it should come from the request itself.
>
> *Visibility of API functions*
> I think initialize(), shutdown() and startJobSubmitter() functions should
> not be part of the API because I don't see a scenario where the gateway
> developer would be responsible for using them. They serve a more internal
> purpose of managing the orchestrator component IMO. As Amila pointed out so
> long ago (wink) functions that do not concern outside parties should not be
> used as part of the API.
>
> *Return values of Orchestrator API*
> IMO unless it is specifically required to do so I think the functions does
> not necessarily need to return anything other than throw exceptions when
> needed. For example the launchExperiment can simply return void if all is
> succesful and return an exception if something fails. Handling issues with
> a try catch is not only simpler but also the explanations are readily
> available for the user.
>
> *Data persisted in registry*
> ExperimentRequest.getUsername() : I think we should clarify what this
> username denotes. In current API, in experiment submission we consider two
> types of users. Submission user (the user who submits the experiment to the
> Airavata Server - this is inferred by the request itself) and the execution
> user (the user who corelates to the application executions of the gateway -
> thus this user can be a different user for different gateway, eg: community
> user, gateway user).
> I think we should persist the date/time of the experiment request as well.
> Also when retrying of API functions in the case of a failure in an
> previous attempt there should be a way to not to repeat already performed
> steps or gracefully roleback and redo those required steps as necessary.
> While such actions could be transparent to the user sometimes it might make
> sense to allow user to be notified of success/failure of a retry. However
> this might mean keeping additional records at the registry level.
>
>


-- 
Thanks,
Sachith Withana

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