Dave Bryson wrote:
>
> I'm in the process of reworking the scheduler service. In doing so, I'm
> looking at
> the need to run each scheduled job in it's own thread.
Yes... it should use its own thread.
> Under the current design, a job is rescheduled to run based upon the
> reoccuring time it's scheduled to run and the time it takes to complete.
> The run queue is sorted and prioritized by this factor. The possible
> problem
> with this is that a long running task can force other jobs to run late
> waiting on
> a job to complete.
Right... that is why it should use it's own threads.
> If I change this to run each job in it's own thread, then the queue will
> be independent
> of the time it takes an individual task to run. So, a task is scheduled
> to run again regardless
> of the time it takes to complete and the scheduler can (in theory) run
> each job on time.
>
> However by doing this, it makes the scheduler function more complex.
> Because now the
> service needs some type of a callback to update the queue and it would
> be possible for
> the scheduler to launch the task to run again even it's not finished
> from it's previous
> execution. For example, in the case that a run again time < time to
> complete. This can
> be solved by setting some type of state check or priority on the job but
> this adds complexity
> to the service.
Not really. Just don't let the new task run if the old task hasn't
finished yet. Then start it (only if the user wants to) if the task
finishes.
> So my question is: What's more important to you? Can we live with a job
> (possibly)
> running a little late; or is the importance of this service worth the
> complexity of seperate thread
> per job?
No... it should always run when I tell it to.
Kevin
--
Kevin A Burton ([EMAIL PROTECTED])
http://relativity.yi.org
Message to SUN: "Please Open Source Java!"
"For evil to win is for good men to do nothing."
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