I have the same question Michael is asking (#1 below). If a
precondition never passes, I do not want that workflow-task to
indefinitely poll on that precondition. At some point (preferably a
configurable amount of time) it should give up and fail (halt) the
workflow. Or is there another way to address this Use Case?
-Keith Cummings
Cayanan, Michael D (388J) wrote:
Hi Chris,
On 3/2/12 9:36 PM, "Mattmann, Chris A (388J)"
<[email protected]> wrote:
Hi Mike,
On Mar 2, 2012, at 9:37 AM, Cayanan, Michael D (388J) wrote:
Hi all,
In the workflow.properties file, I see that I can configure the polling
time if a pre condition fails via the following property:
org.apache.oodt.cas.workflow.engine.preConditionWaitTime
I have a few questions:
1) Is this polling infinite?
What do you mean by "infinite"?
If so, would you have to shut the workflow server down in order to stop
this infinite polling? Or can you shut it down via the workflow manager
client tool?
I'm not sure I follow you? The workflow manager's
ThreadPoolWorkflowEngine needs to evaluate preconditions, on a per
workflow-instance basis.
The only way to shut that down, is to shut down the workflow engine, and
thus implicitly the WM.
In other words, if the pre condition continually fails, will the workflow
ever timeout where the engine shuts down automatically?
2) Is there a way to configure the pre condition wait time through the
PGE config file? For example, if I have 2 PGEs where I want each PGE to
have different pre condition wait times, is this possible?
Can you tell me a specific use case or reason that you would want to have
different condition check times per PGE?
In short, this can be supported by extending the
ThreadPoolWorkflowEngine, and then overriding or mapping the condition
wait
time to whatever is configured for the PGE. I'd severely caution against
doing so, b/c you're really giving the developer or
workflow person an overt amount of control over an aspect of the system
that will affect (perceived) performance.
This was more of a curiosity question than anything. Personally, I don't
see the need to have a configurable pre condition wait time. In SMAP
world, there will be a case where a workflow requires two inputs, where
the inputs are coming from the outputs of 2 different workflows.
Furthermore, 1 of these inputs isn't expected to arrive like 10 hours
later after the first input arrives. The assumption here is that 1 input
will trigger the workflow and thus the pre condition would be to check for
the existence for that other input. So, if you have your precondition wait
time to some small interval like 30 seconds, would system performance be
affected in this case knowing that the precondition isn't expected to be
satisfied until 10 hours later?
Hope this makes sense.
Thanks again for your help!
-Mike
Cheers,
Chris
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Chris Mattmann, Ph.D.
Senior Computer Scientist
NASA Jet Propulsion Laboratory Pasadena, CA 91109 USA
Office: 171-266B, Mailstop: 171-246
Email: [email protected]
WWW: http://sunset.usc.edu/~mattmann/
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Adjunct Assistant Professor, Computer Science Department
University of Southern California, Los Angeles, CA 90089 USA
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