Triggering a workflow

[Raminder Singh <ra...@gmail.com>]

Hi All,

I have a requirent to trigger a workflow on completion of another workflow's successfully execution. Use case is, there is a main workflow for data processing and post processing workflow to run lot of outputs produced during previous steps in parallel. Steps can be built as one workflow but then the workflow becomes complicated and difficult to restart in case of execution failures. It will also take away flexibility to run post processing on different data sets. I want these as separate workflows for validation and for flexibility. Is it possible in Airavata? if yes, please share. If no, what do you think?

Thanks
Raminder  

Re: Triggering a workflow

[Suresh Marru <sm...@apache.org>]

Hi Raman,

When Airavata Workflow Engine was BPEL based, there was event triggering support. But since it moved to Workflow Interpreter, the orchestration has been request based. AFAIK, there is no triggered workflow launch in the interpreter. One trivial way I can think of is to use the API and launch it and have this launch call as a service within the master workflow.

But if I am understanding the use case correctly, it looks like more a better fit for hierarchal worklfows (or sub workflows). If this is the case, technically you should be able to do so, with two caveats. 
* XBaya had support for hierarchal workflow monitoring, but the part which opens a new workflow is based on workflow  instance id. This is probably defunct now since it used to contact GPEL engine to open a workflow. I need to look at the code, but this needs to be revisited to fetch the sub workflow from registry.
* I wonder if the provenance data model might be flat for sub workflows. Probably the messy hierarchies could be tolerated (with some effort on correlation with workflow instance ids') but to make this more first class, I would suggest to revisit the data model as well.

Cheers,
Suresh

On Feb 11, 2013, at 11:49 AM, Raminder Singh <ra...@gmail.com> wrote:

> Hi All,
> 
> I have a requirent to trigger a workflow on completion of another workflow's successfully execution. Use case is, there is a main workflow for data processing and post processing workflow to run lot of outputs produced during previous steps in parallel. Steps can be built as one workflow but then the workflow becomes complicated and difficult to restart in case of execution failures. It will also take away flexibility to run post processing on different data sets. I want these as separate workflows for validation and for flexibility. Is it possible in Airavata? if yes, please share. If no, what do you think?
> 
> Thanks
> Raminder  

Re: Triggering a workflow

[Suresh Marru <sm...@apache.org>]

Hi Raman,

When Airavata Workflow Engine was BPEL based, there was event triggering support. But since it moved to Workflow Interpreter, the orchestration has been request based. AFAIK, there is no triggered workflow launch in the interpreter. One trivial way I can think of is to use the API and launch it and have this launch call as a service within the master workflow.

But if I am understanding the use case correctly, it looks like more a better fit for hierarchal worklfows (or sub workflows). If this is the case, technically you should be able to do so, with two caveats. 
* XBaya had support for hierarchal workflow monitoring, but the part which opens a new workflow is based on workflow  instance id. This is probably defunct now since it used to contact GPEL engine to open a workflow. I need to look at the code, but this needs to be revisited to fetch the sub workflow from registry.
* I wonder if the provenance data model might be flat for sub workflows. Probably the messy hierarchies could be tolerated (with some effort on correlation with workflow instance ids') but to make this more first class, I would suggest to revisit the data model as well.

Cheers,
Suresh

On Feb 11, 2013, at 11:49 AM, Raminder Singh <ra...@gmail.com> wrote:

> Hi All,
> 
> I have a requirent to trigger a workflow on completion of another workflow's successfully execution. Use case is, there is a main workflow for data processing and post processing workflow to run lot of outputs produced during previous steps in parallel. Steps can be built as one workflow but then the workflow becomes complicated and difficult to restart in case of execution failures. It will also take away flexibility to run post processing on different data sets. I want these as separate workflows for validation and for flexibility. Is it possible in Airavata? if yes, please share. If no, what do you think?
> 
> Thanks
> Raminder