The more the better :) If seriously, this one is less detailed and rather focuses on high-level things so that everyone can have a high-level understanding of what’s been going on on Mistral/TaskFlow integration. In other words, this email raises question “What” and doesn’t raise “Why?” while [0] goes deeper into details.
[0] http://lists.openstack.org/pipermail/openstack-dev/2014-April/032461.html Renat Akhmerov @ Mirantis Inc. On 12 Apr 2014, at 00:59, Joshua Harlow <[email protected]> wrote: > I'm confused, why is this 2 emails?? > > http://lists.openstack.org/pipermail/openstack-dev/2014-April/032461.html > > Seems better to just have 1 chain, not 2. > > From: Dmitri Zimine <[email protected]> > Reply-To: "OpenStack Development Mailing List (not for usage questions)" > <[email protected]> > Date: Friday, April 11, 2014 at 9:55 AM > To: "OpenStack Development Mailing List (not for usage questions)" > <[email protected]> > Subject: [openstack-dev] [Mistral][TaskFlow] Mistral-TaskFlow Summary > >> We prototyped Mistral / TaskFlow integration and have a follow-up >> discussions. >> >> SUMMARY: Mistral (Workflow Service) can embed TaskFlow as a workflow >> library, with some required modifications to function resliently as a >> service, and for smooth integration. However, the TaskFlow flow controls are >> insufficient for Mistral use cases. >> >> Details discussed on other thirds. >> The prototype scope - [0]; code and discussion - [1] and techical highlights >> - [2]. >> >> DETAILS: >> >> 1) Embedding TaskFlow inside Mistral: >> * Required: make the engine "lazy" [3], [4].This is required to support >> long-running delegates and not loose tasks when engine manager process >> restarts. >> >> * Persistence: need clarity how to replace or mix-in TaskFlow persistence >> with Mistral persistence. Renat is taking a look. >> >> * Declaring Flows in YAML DSL: done for simplest flow. Need to prototype for >> data flow. Rich flow controls are missing in TaskFlow for a representative >> prototype. >> >> * ActionRunners vs Taskflow Workers - not prototyped. Not a risk: both >> Mistral and TaskFlow implementations work. But we shall resolve the overlap. >> >> * Ignored for now - unlikely any risks: Keystone integration, Mistral event >> scheduler, Mistral declarative services and action definition. >> >> 2) TaskFlow library features >> * Must: flow control - conditional transitions, references, expression >> evaluation, to express real-life workflows [5]. The required flow control >> primitives are 1) repeater 2) flow in flow 3) direct transition 4) >> conditional transition 5) multiple data. TaskFlow has 1) and 2), need to add >> 3/4/5. >> >> * Other details and smaller requests are in the discussion [1] >> >> 3) Next Steps proposed: >> * Mistal team: summarize the requirements discussed and agreed on [2] and [3] >> * Mistral team: code sample (tests?) on how Mistral would like to consume >> TaskFlow lazy engine >> * Taskflow team: Provide a design for alternative TaskExecutor approach >> (prototypes, boxes, arrows, crayons :)) >> * Decide on lazy engine >> * Move the discussion on other elements on integration. >> >> References: >> [0] The scope of the prototype: >> https://etherpad.openstack.org/p/mistral-taskflow-prototype >> [1] Prototype code and discussion https://github.com/enykeev/mistral/pull/1 >> [2] Techical summary >> http://lists.openstack.org/pipermail/openstack-dev/2014-April/032461.html >> [3] Email discussion on TaskFlow lazy eninge >> http://lists.openstack.org/pipermail/openstack-dev/2014-March/031134.html >> [4] IRC discussion Mistral/Taskflow http://paste.openstack.org/show/75389/ >> [5] Use cases https://github.com/dzimine/mistral-workflows/tree/add-usecases > _______________________________________________ > OpenStack-dev mailing list > [email protected] > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
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