Workflows in TOSCA

[Oliver Kopp <koppdev@gmail.com>]

Dear OASIS TC,

I read the PRD 02 of Version 1.1 and read about the simple workflow language.

I have a background of several years in the area of workflow
management. I was at the IAAS, which build a workflow-engine for BPEL
(research prototype) and I know one main contributor of Apache ODE
pretty well and also the founders of Camunda, which build a very good
BPMN engine.

We also use BPEL and BPMN in context of TOSCA 1.0 and it works.

Seeing the workflow language in the specification, I think, the
language is well-suited for short running tasks. But what about
long-running processes? Such as monitoring the application. What about
human tasks? What if I need an Oracle license? How can I do that with
the proposed language? What about complex fault handling? What about
reversing actions (compensation!)? This is all possible with BPEL and
BPMN engines.

We also showed than one can combine declarative and imperative
provisioning using BPEL:
Breitenbücher, Uwe et al.: Combining Declarative and Imperative Cloud
Application Provisioning based on TOSCA. In: Proceedings of the IEEE
International Conference on Cloud Engineering (IC2E), 2014.
http://www.iaas.uni-stuttgart.de/RUS-data/INPROC-2014-21%20-%20Combining%20Declarative%20and%20Imperative%20Cloud%20Application%20Provisioning%20based%20on%20TOSCA.pdf

We also have REST extensions for BPEL and also a simplified syntax for
BPEL (http://bpelscript.org/).


TOSCA aims for portability. It has been shown that BPEL and BPMN are
portable. Not all construcuts, but the most important ones. An
overview is given here: https://peace-project.github.io/


In TOSCA 1.0, this was acknowledged. One could add arbitrary
management plans. Winery (http://eclipse.org/winery/) also supports
that. We also offer an open-source BPMN Modeler with direct support of
TOSCA. Source: https://github.com/winery/BPMN4TOSCAModeler. The result
is converted to BPEL processes, which have been successfully deployed
on the WSO2 BPS, but can also deployed on other BPEL engines.


All in all, I would like to ask the TC if it was possible to bring
back the support of established workflow languages and not restrict
the implementors to one language.

Greetings from Stuttgart,

Oliver