OASIS Topology and Orchestration Specification for Cloud Applications (TOSCA) TC

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Re: [tosca] Re:[tosca] RE: Re:[tosca] Groups - Issue_TOSCA318_Lack of BPMN BPEL support-v1.0.pptx uploaded

  • 1.  Re: [tosca] Re:[tosca] RE: Re:[tosca] Groups - Issue_TOSCA318_Lack of BPMN BPEL support-v1.0.pptx uploaded

    Posted 03-29-2017 00:54
    Hi all, First of, I would like to apologize for joining this thread just now. The fact of the matter is that we felt this is an important discussion and decision and therefore we needed to invest more time analyzing the current proposal and impact of supporting BPMN/BPML/BPEL. In general I think that Luc did a great job both in the 1.1 proposal and also by outlining the general approach on how we should handle workflows in TOSCA in order to allow better portability and at the same time make it simple. I would like to start with something that I feel we all may be correct in some way, but the solution often depends on the context. In this case, different approaches may be related to what each of us mean by "workflow". Like in many other cases, it is an overloaded term. I don't think we want to get into an academical debate and spend huge efforts in creating a common definition, but if we could accept a definition and use case for workflow it would be easier to discuss the potential benefit or disadvantages of integrating BPMN/BPML/BPEL into this model. Recently I started collecting various perspectives and putting together an analysis on this topic (rough Draft at this point, but it will posted soon and I will be ready to share with those interested). I would like to quote specifically the workflow definition as it provides an important framing for this discussion: <snip> DevOps Workflow: Workflow is an orchestrated and repeatable pattern representing an execution plan expressed as a directed graph of tasks – simple to define, to reason, to execute and to visualize . DevOps workflow are used to orchestrate operations in infrastructure and applications, automate complex CI/CD processes etc. A typical use case for DevOps workflow include “Day 0” operations such as Install/uninstall workflow - execute the lifecycle operation of an application and its associated infrastructure. Things get vastly more complex in case of workflow that deal processes that need to update/change an existing deployment, based on “Day 2” operations. A typical set of workflows that fits into this category includes: Heal workflow - fix a failed node (typically by re-executing the failed node lifecycle operation and relationship) Scale workflow - increase the capacity of a given application node (typically by executing the lifecycle operation of the target node multiple time on each scale instance) Update workflow - a common pattern for update is referred to as blue/green. (A typical implementation includes taking a snapshot of the current state -> pushing the new update -> redirecting traffic to the new deployment -> gradually redirect all traffic to the new version -> if failed roll-back to the previous version) Topology update (aka as blueprint update) - adding/removing an entire service from and existing application topology. A typical implementation includes comparing the new blueprint with the existing version->identifying the changes -> executing the changes and updating the model accordingly. There are basically two main approaches for workflow execution: a task-based approach vs a model-driven approach. In a task-based system we execute a workflow by breaking it into a specific set of tasks. For example let’s imagine a simple use case of installing a nodeJS instance on a virtual machine. The workflow for that task include the following steps: Provision the VM Setup network (public/private IP, security group etc) Install and configure the nodeJS instance Start the nodeJS instance In a task-based system I will need to map every step as a task and execute it. In a model-driven approach I would define the model first. The workflow execution will be driven from the model and would be generated implicitly. The Core Components of a model-driven workflow are: Model (Graph) - describes the nodes and their relationship State - maintain the actual state of execution of each node. Execution - the actual code that maps to the specific lifecycle operation of each node. The key differences between a model-driven and task-driven approach is that task-driven approach tends to be purpose-built (allows for more specificity, but less re-usability) while the model-driven approach lends itself to be more tend to be more generic/flexible In other words, a model-driven workflow is simpler to change as it groups the tasks into their respective node-types and thus provide more coarse-grain building blocks that are easier to change and maintain. It’s also easier to read and follow and fits better with a designer task. <snip> I am sure you guessed that the task-based approach is exemplified by BPMN/BPML/BPEL, and the model-driven approach is exemplified by the TOSCA-native approach to workflows. I would also like to end with the conclusion that we see from that analysis: <snip> Conclusion: In conclusion, the turn-around in TOSCA towards the declarative, model-driven approach for workflows is a very positive move, and will help TOSCA to have “a good year in 2017”. There is really nothing wrong with using BPMN/BPML/BPEL, where appropriate. But there is something to be said when we try to use a complex specification designed for a different set of applications, in a domain where an approach that is simple, flexible, re-usable fits better, and the word is “overkill”. So let’s support the “good year of TOSCA” initiative by embracing the TOSCA_YAML_V1.1 approach , and focus on the progress of the improved TOSCA_YAML_V1.2, and future versions planned!" <snip> Thanks all for your patience in reading my lengthy response; I am looking forward to continue staying engaged until we find the right solution for the problem space. Best regards, Michael On Mon, Mar 27, 2017 at 6:57 AM, < zhao.huabing@zte.com.cn > wrote: Hi Luc, Please see my inline comments. Thanks, Huabing Original Mail Sender:  < luc.boutier@fastconnect.fr >; To:  zhaohuabing10201488; CC:  < lauwers@ubicity.com >; < mrutkows@us.ibm.com >; < tosca@lists.oasis-open.org >; < claude.noshpitz@att.com >; < paul.lipton@ca.com >; < lishitao@huawei.com >; MengZhao Xing10024238; Date:  2017/03/27 16:10 Subject:  Re: [tosca] Re:[tosca] RE: Re:[tosca] Groups - Issue_TOSCA318_Lack of BPMN BPEL support-v1.0.pptx uploaded  Hi Huabing,   I realized you made your own choices out of the TC and really want them to be standard now.  Huabing: I didn't mea that(make my own choices), It's the intention of broader audience/users of TOSCA (Service Provider:AT&T, CMCC, Vendor:Huawei, ZTE and research group:University of Stuttgart) to keep BPMN/BPEL in TOSCA, based on their own experiences and requirements, I think we all have heard their concerns in the proposal presentation and open comments maillist.   Also I thought it's the conclusion of the last meeting that  I've confirmed by mails. You are talking a lot about scenarios that cannot be done with current  TOSCA but I still don’t see them to be honest. I think that current workflow + artifact types/artifact type executors can do everything, even manual operations as you can make an artifact type/artifact type executor that will prompt user. It’s just that it  follows a TOSCA compliant way to do so, and compliant in 2 ways: -           Can be triggered through imperative workflows -           Can be included in a declarative generated workflow (this is critical as this is kind of the goal of TOSCA). BPMN taks are not defined on TOSCA nodes and cannot be triggered through declarative generated workflows. This is again why it’s not a good target for TOSCA and  for what we try to achieve.   Huabing: Ideally, yes, we can add everything which not inside TOSCA in term of an artifact. But it imply that we have to implement another "Workflow execution Engine" which has the similar functionalities of an arbitrary mature workflow execution engine, in a different way, which would be a lot of work and  it's not the main goal of orchestration. You asked for better choice we already provided one: -           artifact type approach is absolutely valid and allow to have both portability kept and BPMN execution possible, so this is to me the better approach  that we BTW agreed on on the calls. Not sure you understood what I write in my previous email but I feel that delegate or artifact type are quite the same thing here. And no, I’m not in favour of losing portability again, and to be honest not in favour of supporting any workflow languages as long as we don’t have a way to make  it portable (I mean internally do what you want and as I explained already you can use internally a BPMN engine to process your TOSCA, that is your choice). I think that TOSCA exists for quite a long time now and we didn’t had really portability, right now every implementer made their own choices (that’s what you  did, that’s what GigaSpaces did, that’s also what we did in our tool – for the yet not fully standardize custom artifact executions). Based on that I feel that there is 2 path for TOSCA: -           Stop trying to solve the execution issue and be just a modelling language (drop interfaces and operations) and let people provide imperative specific  means to make things executed through other specs (BPMN etc.) or other means (Docker compose, Kubernetes models or other declarative approaches that comes). -           Keep trying to address the initial challenge which is to try to build a portable declarative and executable standard (well that’s quick sentence but  I think it was the main points of TOSCA somehow). So I’m sorry but no I cannot kindly agree with something that I really feels as a wrong path. That said if I’m the only one to feel that way please let me know  as we should probably stop a lot of work we started here (including artifact type executor and let people just do their own custom non portable things). Huabing: What we're asking is not an "A" or  "B" choice for workflow standard, instead, we'd like to keep workflow choice open so the implementation could choose whatever workflow which make sense based on their requirement. So we don't have to stop what we're working on right now to incorporate BPMN/BPEL into TOSCA. Luc   From: " zhao.huabing@zte.com.cn " < zhao.huabing@zte.com.cn > Date: Monday, 27 March 2017 at 04:44 To: Luc Boutier < luc.boutier@fastconnect.fr > Cc: Chris Lauwers < lauwers@ubicity.com >, Matthew Rutkowski < mrutkows@us.ibm.com >, " tosca@lists.oasis-open.org " < tosca@lists.oasis-open.org >, " claude.noshpitz@att.com " < claude.noshpitz@att.com >, Paul Lipton < paul.lipton@ca.com >, shitao li < lishitao@huawei.com >,  " meng.zhaoxing1@zte.com.cn " < meng.zhaoxing1@zte.com.cn > Subject: Re: [tosca] Re:[tosca] RE: Re:[tosca] Groups - Issue_TOSCA318_Lack of BPMN BPEL support-v1.0.pptx uploaded    Hi Luc, I think Chirs' suggestion make sense. Just like a famous western saying: "Rome wasn't built in a day", it's not realistic to try to work out a "perfect" solution overnight. We need to solve the issue we currently faced and allow it evolve towards the right direction in the same time. I'd like  to say that there might be a solution close to but not "perfect" solution at all, becasue things always change.    Furthermore, I don't think exclusive approach is the best choice for workflow. Because there is no a silver bullet to solve all the problems. Just as what I and Claud were saying in the last proposal presentation, there were still some scenarios which tosca  workflow can't handle with right now, which have already been implemented by BPMN/BPEL in OpenECOMP/OPEN-O/OpenTOSCA.   I will be appreciate if you could kindly agree this approach or you can figure out a better one to address it in a short term.   Thanks, Huabing Original Mail Sender:  < luc.boutier@fastconnect.fr > ; To:  < lauwers@ubicity.com > ; zhaohuabing10201488; CC:  < mrutkows@us.ibm.com > ; < tosca@lists.oasis-open.org > ; < claude.noshpitz@att.com > ; < paul.lipton@ca.com > ; < lishitao@huawei.com > ; MengZhaoXing10024238; Date:  2017/03/25 04:35 Subject: Re: [tosca] Re:[tosca] RE: Re:[tosca] Groups - Issue_TOSCA318_Lack of BPMN BPEL support-v1.0.pptx uploaded   Hi Chris,   I see no real difference with this delegate proposal and an operation within the workflow except that  operation with artifact type is something we are working  on and could provide portable and normative support.   We can write a TOSCA 1.1 workflow with set_state at the end and a single call to the BPMN artifact  operation, that is really similar to what you propose but leveraging  planned 1.2 standard definitions (once we finish the artifact type and artifact executor definition). If not we will end up with a delegate that orchestrator does not know how to handle,  delegate is intended for orchestrator provided nodes (matched abstract  nodes – so specific to orchestrator). Or only some specific impl will know how to handle them? And this will be custom per Impl and for no more benefits that the simple artifact support  that we proposed.   Once again, I really think that we should work on instance model and API before we go further. And  also complete the work on custom artifact type support because  even this is not fully completed yet and seems on hold since we discuss this BPMN/BPEL elements rather moving forward. I really believe that more than making some people happy we should focus  on trying to build a reliable standard. This is exactly why we worked  on the workflow spec in 1.1. because there where nothing people could really rely on in previous spec. Declarative workflows ordering was not clearly defined and saying that multiple workflows  languages could be consider was not a reliable statement and actually  just lead us to the point we are now with people making their own choices out of the TC and trying to find a reconciliation rather than moving forward on the multiple challenges we should  address.   I think that in this perspective the work started on artifact type support is critical and we should  complete that work rather than trying to solve all issues  and especially elements that will not bring more to TOSCA but just please people (I am still not seeing anything that is TOSCA compliant that cannot be done with the actual workflow language – and  not TOSCA compliant elements should currently be supported  through specific artifacts). I still feel on my own that other workflows language will weaken TOSCA as they are not compliant with the TOSCA way to define and call operations and especially the current  artifact type work.   That said I don’t say we should not consider the support of specific workflow languages in the future,  I just feel that we should not make wrong choices to please  people while some elements are not ready yet in TOSCA.   Anyway, we just don’t agree here I guess,   Luc   From: Chris Lauwers < lauwers@ubicity.com > Date: Friday, 24 March 2017 at 18:29 To: Luc Boutier < luc.boutier@fastconnect.fr >, " zhao.huabing@zte.com.cn " < zhao.huabing@zte.com.cn > Cc: Matthew Rutkowski < mrutkows@us.ibm.com >, "tosca@lists..oasis-open..org" < tosca@lists.oasis-open.org >, " claude.noshpitz@att.com " < claude.noshpitz@att.com >, Paul Lipton < paul.lipton@ca.com >, shitao  li < lishitao@huawei.com >, " meng.zhaoxing1@zte.com.cn "  < meng.zhaoxing1@zte.com.cn > Subject: RE: [tosca] Re:[tosca] RE: Re:[tosca] Groups - Issue_TOSCA318_Lack of BPMN BPEL support-v1.0.pptx uploaded   Hi Luc,   While I generally agree with the “walk before you run” approach, I believe there might be a very simple way to accommodate  what Huabing wants. How about the following:   1.       We already have a “delegate” keyname on workflow activities. What if in addition, we also allowed a “delegate” keyname on a top-level workflow definition? This would  signal  to the orchestrator (in a standardized way) that the workflow would be taken over entirely by an external entity. The argument of the “delegate” keyname would be the artifact name of the BPNM or BPEL workflow (for which we would obviously still need  to define  a processor). 2.       I also agree that in order to do this correctly, we will have to standardize an API to the instance model, and more sophisticated TOSCA workflows could benefit from  such  an API as well. However, the API available to TOSCA workflows today is limited to “set_state” and “call_operation”. At the very least, we could make those operations available to external workflows, which would put these external workflows on-par with  TOSCA  workflows.   While this doesn’t entirely address your “portability” concerns, at least it provides a standard way for template  designers to signal to the orchestrator that responsibility  for orchestration needs to be delegated to an external workflow engine.   thanks,   Chris       From: BOUTIER, LUC [mailto: luc.boutier@ fastconnect.fr ] Sent: Wednesday, March 22, 2017 11:31 PM To: Chris Lauwers < lauwers@ubicity.com >; zhao.huabing@zte.com.cn Cc: mrutkows@us.. ibm.com ; tosca@lists.oasis-open.org ; claude.noshpitz@att.com ; paul.lipton@ca.com ; lishitao@huawei.com ; meng.zhaoxing1@zte.com.cn Subject: Re: [tosca] Re:[tosca] RE: Re:[tosca] Groups - Issue_TOSCA318_Lack of BPMN BPEL support-v1.0.pptx uploaded   Chris, Huabing,   I think that we should not constraint 1.2 on custom workflow support and that we should try to go step by step: 1.       We still don’t have artifact type executors completed and I think this is the first step we need to complete 2.       We still don’t have an instance model 3.       And once instance model is defined we will need also an instance model API to be defined and agreed   Instance model and Instance model APIs are pre-requisite for any kind of workflow extensions are workflow execution extensions  will mean workflow engines external to the TOSCA orchestrator,  or there won’t be portability as we cannot expect or have as a pre-requisite for TOSCA orchestrator to support any kind of Workflow languages especially open workflow languages supporting extensions  (meaning not supported everywhere).   So, my suggestion is that the 1.2 target should define a way to execute custom operation types in a portable way and we need to  have this work completed (this is the great work started  by Chris). BPMN or BPEL in 1.2 will be artifact types with the limitations Chris mentioned.   As we say in France « Il ne faut pas mettre la charrue avant les bœufs »   Luc   From: < tosca@lists..oasis-open.org > on behalf of Chris Lauwers < lauwers@ubicity.com > Date: Thursday, 23 March 2017 at 05:58 To: " zhao.huabing@zte.com.cn " < zhao.huabing@zte.com.cn > Cc: Matthew Rutkowski < mrutkows@us.ibm.com >, " tosca@lists.oasis-open.org " < tosca@lists.oasis-open.org >,  " claude.noshpitz@att.com "  < claude.noshpitz@att.com >, Paul Lipton < paul.lipton@ca.com >,  shitao li < lishitao@huawei.com >, " meng..zhaoxing1@zte.com.cn "  < meng.zhaoxing1@zte.com.cn > Subject: RE: [tosca] Re:[tosca] RE: Re:[tosca] Groups - Issue_TOSCA318_Lack of BPMN BPEL support-v1.0.pptx uploaded   I’m not sure about the timeframe. Matt should chime in on this.   Thanks,   Chris   From: tosca@lists.oasis-open.org [ mailto:tosca@lists.oasis- open.org ] On Behalf Of zhao.huabing@zte.com.cn Sent: Wednesday, March 22, 2017 9:57 PM To: Chris Lauwers < lauwers@ubicity.com > Cc: mrutkows@us.ibm.com ; tosca@lists.oasis-open.org ; claude.noshpitz@att.com ; paul.lipton@ca.com ; lishitao@huawei.com ; meng.zhaoxing1@zte.com.cn Subject: [tosca] Re:[tosca] RE: Re:[tosca] Groups - Issue_TOSCA318_Lack of BPMN BPEL support-v1.0.pptx uploaded   Hi Chris, Thanks for your explanation. That's exactly what I'm curious about.  So we're planing planning to add arbitrary artifact implementations for the entire workflow of the topology template in 1.2, such as BPMN, BPEL, Node-RED,Ballerina etc.?   Thanks, Huabing Original Mail Sender:  < lauwers@ubicity.com > ; To:  zhaohuabing10201488; < mrutkows@us.ibm.com > ; CC:  < tosca@lists.oasis-open.org > ; < claude.noshpitz@att.com > ; < paul.lipton@ca.com > ; < lishitao@huawei.com > ; MengZhaoXing10024238; Date:  2017/03/23 12:21 Subject: [tosca] RE: Re:[tosca] Groups - Issue_TOSCA318_Lack of BPMN BPEL support-v1.0.pptx uploaded   Hi Huabing,   Yes, your understanding of the plan is correct.   However, in the current version of the spec, artifacts can only be used to provide implementations for operations. For example,   this means that you will be able to specify  a BPEL workflow to implement the “create” operation on the Standard lifecycle operation.   We currently don’t have a mechanism to use artifacts as implementations for entire workflows. This will need to get added in a   later version.   Thanks,   Chris   From: zhao.huabing@zte.com.cn [ mailto:zhao.huabing@zte.com. cn ] Sent: Tuesday, March 21, 2017 4:41 AM To: mrutkows@us.ibm.com ; Chris Lauwers < lauwers@ubicity.com > Cc: tosca@lists.oasis-open.org ; claude.noshpitz@att.com ; paul.lipton@ca.com ; lishitao@huawei.com ; meng.zhaoxing1@zte.com.cn Subject: Re:[tosca] Groups - Issue_TOSCA318_Lack of BPMN BPEL support-v1.0.pptx uploaded   Hi Matt, Chris,   I haven't find any update about this in my inbox, did I miss anything? I guess the idea is that TOSCA could take BPMN/BPEL as an artifact type and it can be executed by an artifact processor(workflow execution engine) provided by orchestrator, right?   Thanks, Huabing   Original Mail Sender:  zhaohuabing10201488 To:  < mrutkows@us.ibm.com > ; < lauwers@ubicity.com > ; CC:  < tosca@lists.oasis-open.org > ; < claude.noshpitz@att.com > ; < paul.lipton@ca.com > ; < lishitao@huawei.com > ; MengZhaoXing10024238; Date:  2017/03/16 09:54 Subject: Re:[tosca] Groups - Issue_TOSCA318_Lack of BPMN BPEL support-v1.0.pptx uploaded   Hi Matt, Thanks for uploading the slide deck. Do we have a minutes for this meeting? I'm still improving my English skill, so I have difficulty to get all the points of everyone in this meeting... Is the conclusion that we'll incorporate BPMN/BPEL workflow as artifact in the later version of simple YAML and Chris are working on that?   Thanks, Huabing     Sender:  < mrutkows@us.ibm.com > ; To:  < tosca@lists.oasis-open.org > ; Date:  2017/03/15 23:16 Subject: [tosca] Groups - Issue_TOSCA318_Lack of BPMN BPEL support-v1.0.pptx uploaded   Submitter's message         Parts of these slides were presented during the 2017-03-14 Simple Profile WG meeting.         -- Mr. Matthew Rutkowski Document Name : Issue_TOSCA318_Lack of BPMN BPEL support-v1.0.pptx         No description provided...                 Download Latest Revision         Public Download Link         Submitter : Mr. Matthew Rutkowski                 Group : OASIS Topology and Orchestration Specification for Cloud Applications (TOSCA) TC         Folder : Working Documents         Date submitted : 2017-03-15 08:15:37                                         ------------------------------ ------------------------------ --------- To unsubscribe from this mail list, you must leave the OASIS TC that generates this mail.  Follow this link to all your TCs in OASIS at: https://www.oasis-open.org/ apps/org/workgroup/portal/my_ workgroups.php


  • 2.  RE: [tosca] Re:[tosca] RE: Re:[tosca] Groups - Issue_TOSCA318_Lack of BPMN BPEL support-v1.0.pptx uploaded

    Posted 04-07-2017 21:18




    Hi Michael,
     
    Thanks for your detailed write-up. When you finish your document on this topic, I’d love to get a copy.
     
    A couple of comments:
     

    I agree with your Day 1 vs. Day 2 distinction. TOSCA so far has focused primarily on Day 1 deployments, but in my
    opinion the real value is in Day 2 operations. I believe this will require more progress on “instance models” that capture operational state, since the Day 2 workflows you mentioned are really implementation of autonomic processes that manipulate  “operational
    state”. I also agree with your distinction between “model-driven” vs. “task-driven” approaches to workflows. In fact, the
    TOSCA spec owes up to this distinction by specifying both “imperative” and “declarative” workflows. Declarative workflows are created automatically by the orchestrators, whereas imperative workflows must be specified by the service template designer using
    the workflow language introduced in TOSCA Simple Profile for YAML v1.1. Declarative workflows in TOSCA don’t require service template designers to specify any workflow at all: the “declarative” workflow is derived automatically by the orchestrator by leveraging
    implementations (“artifacts”) of operations that are part of the standard lifecycle management interfaces.
    From that point-of-view, the question whether to use TOSCA’s imperative workflow language or BPEL or BPMN is actually
    a valid question, in my opinion, because either one could be used to specify “imperative” workflows. The advantage of TOSCA’s built-in workflow language is obviously that it integrates better with the rest of TOSCA, whereas more work is need to allow external
    workflow engines to operate on TOSCA models. The real question we should focus on, then, (and you alluded to this as well) is why there should be a need to use
    imperative workflows at all? What are the use cases that cannot be solved using declarative workflows and require imperative workflows instead? I would much rather focus our energy on answering this question, since it will lead to improvements to the language
    that will make declarative workflows more flexible and more widely applicable.
    I’ve given some thought to the types of extensions that may be required to make declarative workflows more usable.
    The following come to mind:

    Introduce interface-specific state variables. We currently assume that there is one node state variable that captures
    lifecycle management state for that node. For other types of interfaces (such as your healing or scaling interfaces), this state is not useful. We either need additional state values, or additional state variables, or both. The best solution, in my opinion,
    is to move the state variable into the interface. Introduce additional metadata for lifecycle operations. For example: what are the pre-conditions that need to be
    met before the operation can be executed (e.g. what state does the node/interface need to be in?). Are there any side effects to the operation (e.g. node/interface transitions into a different state). Such metadata is currently supported in the TOSCA imperative
    workflow, but in my opinion much of this belongs with the operations themselves, not with the workflow. Introduce additional metadata for interfaces themselves. For example: relationship interfaces currently don’t allow
    the interface type designer to specify any ordering relationships between operations called on source node vs. operations called on target nodes. Instead, orchestrators are supposed to know the proper ordering for the normative relationship types. This means
    that it is not possible to introduce custom relationship interfaces without also specifying a declarative workflow.  We need some type of mechanism for specifying operations ordering.


     
    I look forward to further discussion about this topic.
     
    Thanks,
     
    Chris
     
     
    From: Michael Brenner [mailto:michael@gigaspaces.com]

    Sent: Tuesday, March 28, 2017 5:54 PM
    To: zhao.huabing@zte.com.cn
    Cc: BOUTIER, LUC <luc.boutier@fastconnect.fr>; Chris Lauwers <lauwers@ubicity.com>; Matt Rutkowski <mrutkows@us.ibm.com>; tosca@lists.oasis-open.org; claude.noshpitz@att.com; Lipton, Paul C <paul.lipton@ca.com>; Lishitao <lishitao@huawei.com>; meng.zhaoxing1@zte.com.cn;
    Nati Shalom <natis@gigaspaces.com>; Arthur Berezin <arthur@gigaspaces.com>; Amir Levy <amir@gigaspaces.com>; Sivan Barzily <sivan@gigaspaces.com>; Tal Liron <tal@gigaspaces.com>
    Subject: Re: [tosca] Re:[tosca] RE: Re:[tosca] Groups - Issue_TOSCA318_Lack of BPMN BPEL support-v1.0.pptx uploaded
     

    Hi all,

     


    First of, I would like to apologize for joining this thread just now.



    The fact of the matter is that we felt this is an important discussion and decision and therefore we needed to invest more time analyzing the current proposal and impact of supporting BPMN/BPML/BPEL.


     


    In general I think that Luc did a great job both in the 1.1 proposal and also by outlining the general approach on how we should handle workflows in TOSCA in order to allow better portability
    and at the same time make it simple.


     


    I would like to start with something that I feel we all may be correct in some way, but the solution often depends on the context. In this case, different approaches may be related to what each
    of us mean by "workflow". Like in many other cases, it is an overloaded term. I don't think we want to get into an academical debate and spend huge efforts in creating a common definition, but if we could accept a definition and use case for workflow it would
    be easier to discuss the potential benefit or disadvantages of integrating BPMN/BPML/BPEL into this model.


     


    Recently I started collecting various perspectives and putting together an analysis on this topic (rough Draft at this point, but it will posted soon and I will be ready to share with those interested).


     


    I would like to quote specifically the workflow definition as it provides an important framing for this discussion:


     


    <snip>


    DevOps Workflow:


    Workflow is an orchestrated and repeatable pattern representing an execution plan expressed as a directed graph
    of tasks – simple to define, to reason, to execute and to visualize.


    DevOps workflow are used to orchestrate operations in infrastructure and applications, automate complex CI/CD processes etc.
     

    A typical use case for DevOps workflow include “Day 0” operations such as Install/uninstall workflow - execute the lifecycle operation
    of an application and its associated infrastructure.
     

    Things get vastly more complex in case of workflow that deal processes that need to update/change an existing deployment, based on
    “Day 2” operations. A typical set of workflows that fits into this category includes:

     

    ·  
    Heal workflow - fix a failed node (typically by re-executing the failed node lifecycle operation and
    relationship)

    ·  
    Scale workflow - increase the capacity of a given application node (typically by executing the lifecycle
    operation of the target node multiple time on each scale instance)

    ·  
    Update workflow - a common pattern for update is referred to as blue/green. (A typical implementation
    includes taking a snapshot of the current state -> pushing the new update -> redirecting traffic to the new deployment -> gradually redirect all traffic to the new version -> if failed roll-back to the previous version)

    ·  
    Topology update (aka as blueprint update) - adding/removing an entire service from and existing application
    topology. A typical implementation includes comparing the new blueprint with the existing version->identifying the changes -> executing the changes and updating the model accordingly.
     

    There are basically two main approaches for workflow execution: a task-based approach vs a model-driven approach.

    In a task-based system we execute a workflow by breaking it into a specific set of tasks. For example let’s imagine a simple use
    case of installing a nodeJS instance on a virtual machine.

    The workflow for that task include the following steps:
     

    1.       
    Provision the VM

    2.       
    Setup network (public/private IP, security group etc)

    3.       
    Install and configure the nodeJS instance

    4.       
    Start the nodeJS instance
     

    In a task-based system I will need to map every step as a task and execute it.
     

    In a model-driven approach I would define the model first. The workflow execution will be driven from the model and would be generated
    implicitly.

    The Core Components of a model-driven workflow are:
     

    ·  
    Model (Graph) - describes the nodes and their relationship

    ·  
    State - maintain the actual state of execution of each node.


    ·  
    Execution - the actual code that maps to the specific lifecycle operation of each node.
     

    The key differences between a model-driven and task-driven approach is that task-driven approach tends to be purpose-built (allows
    for more specificity, but less re-usability) while the model-driven approach lends itself to be more tend to be more generic/flexible

    In other words, a model-driven workflow is simpler to change as it groups the tasks into their respective node-types and thus provide
    more coarse-grain building blocks that are easier to change and maintain. It’s also easier to read and follow and fits better with a designer task.

    <snip>

    I am sure you guessed that the task-based approach is exemplified by BPMN/BPML/BPEL, and the model-driven approach is exemplified by the TOSCA-native approach to workflows.


     


    I would also like to end with the conclusion that we see from that analysis:


     


    <snip>


    Conclusion:



    In conclusion, the turn-around in TOSCA towards the declarative, model-driven approach for workflows is a very positive move, and
    will help TOSCA to have “a good year in 2017”. There is really nothing wrong with using BPMN/BPML/BPEL, where appropriate. But there is something to be said when we try to use a complex specification designed for a different set of applications, in a domain
    where an approach that is simple, flexible, re-usable fits better, and the word is “overkill”.


    So let’s support the “good year of TOSCA” initiative by embracing the TOSCA_YAML_V1.1 approach , and focus on the progress of the
    improved TOSCA_YAML_V1.2, and future versions planned!"

    <snip>

    Thanks all for your patience in reading my lengthy response; I am looking forward to continue staying engaged until we find the right solution for the problem space.

     

    Best regards,

    Michael





     

    On Mon, Mar 27, 2017 at 6:57 AM, < zhao.huabing@zte.com.cn > wrote:


    Hi Luc,
    Please see my inline comments.
     
    Thanks,
    Huabing



    Original Mail




    Sender: 
    < luc.boutier@fastconnect.fr > ;


    To:  zhaohuabing10201488;


    CC: 
    < lauwers@ubicity.com > ;
    < mrutkows@us.ibm.com > ;
    < tosca@lists.oasis-open.org > ;
    < claude.noshpitz@att.com > ;
    < paul.lipton@ca.com > ;
    < lishitao@huawei.com > ;MengZhaoXing10024238;


    Date:  2017/03/27 16:10


    Subject: Re: [tosca] Re:[tosca] RE: Re:[tosca] Groups - Issue_TOSCA318_Lack of BPMN BPEL support-v1.0.pptx uploaded 


     


    Hi Huabing,
     
    I realized you made your own choices out of the TC and really want them to be standard now. 
    Huabing: I didn't mea that(make my own choices), It's the intention of broader audience/users
    of TOSCA (Service Provider:AT&T, CMCC, Vendor:Huawei, ZTE and research group:University of Stuttgart) to keep BPMN/BPEL in TOSCA, based on their own experiences and requirements, I think we all have heard their concerns in the proposal presentation and open
    comments maillist.   Also I thought it's the conclusion of the last meeting that I've confirmed by mails.
     
    You are talking a lot about scenarios that cannot be done with current  TOSCA but I still don’t see them to be honest.
    I think that current workflow + artifact types/artifact type executors can do everything, even manual operations as you can make an artifact type/artifact type executor that will prompt user. It’s just that it  follows a TOSCA compliant way to do so, and compliant
    in 2 ways:
    -          
    Can be triggered through imperative workflows
    -          
    Can be included in a declarative generated workflow (this is critical as this is kind of the goal of TOSCA).
    BPMN taks are not defined on TOSCA nodes and cannot be triggered through declarative generated workflows. This is
    again why it’s not a good target for TOSCA and  for what we try to achieve.
      Huabing: Ideally, yes, we can add everything which not inside TOSCA in term of
    an artifact. But it imply that we have to implement another "Workflow execution Engine" which has the similar functionalities of an arbitrary mature workflow execution engine, in a different way, which would be a lot of work and it's not the main goal of orchestration.
    You asked for better choice we already provided one:
    -          
    artifact type approach is absolutely valid and allow to have both portability kept and BPMN execution possible, so this is to me the better approach  that we BTW agreed on on the calls.
    Not sure you understood what I write in my previous email but I feel that delegate or artifact type are quite the same thing here.
    And no, I’m not in favour of losing portability again, and to be honest not in favour of supporting any workflow
    languages as long as we don’t have a way to make  it portable (I mean internally do what you want and as I explained already you can use internally a BPMN engine to process your TOSCA, that is your choice).
     
    I think that TOSCA exists for quite a long time now and we didn’t had really portability, right now every implementer
    made their own choices (that’s what you  did, that’s what GigaSpaces did, that’s also what we did in our tool – for the yet not fully standardize custom artifact executions). Based on that I feel that there is 2 path for TOSCA:
    -          
    Stop trying to solve the execution issue and be just a modelling language (drop interfaces and operations) and let people provide imperative specific  means to make things executed through
    other specs (BPMN etc.) or other means (Docker compose, Kubernetes models or other declarative approaches that comes).
    -          
    Keep trying to address the initial challenge which is to try to build a portable declarative and executable standard (well that’s quick sentence but  I think it was the main points of TOSCA
    somehow).
    So I’m sorry but no I cannot kindly agree with something that I really feels as a wrong path. That said if I’m the
    only one to feel that way please let me know  as we should probably stop a lot of work we started here (including artifact type executor and let people just do their own custom non portable things).
    Huabing: What we're asking is not an "A" or  "B" choice for workflow standard, instead, we'd like
    to keep workflow choice open so the implementation could choose whatever workflow which make sense based on their requirement. So we don't have to stop what we're working on right now to incorporate BPMN/BPEL into TOSCA.


    Luc
     

    From:
    " zhao.huabing@zte.com.cn "
    < zhao.huabing@zte.com.cn >
    Date: Monday, 27 March 2017 at 04:44
    To: Luc Boutier
    < luc.boutier@fastconnect.fr >
    Cc: Chris Lauwers
    < lauwers@ubicity.com > ,
    Matthew Rutkowski < mrutkows@us.ibm.com > ,
    " tosca@lists.oasis-open.org "
    < tosca@lists.oasis-open.org > ,
    " claude.noshpitz@att.com "
    < claude.noshpitz@att.com > ,
    Paul Lipton < paul.lipton@ca.com > ,
    shitao li < lishitao@huawei.com > ,
     " meng.zhaoxing1@zte.com.cn "
    < meng.zhaoxing1@zte.com.cn >
    Subject: Re: [tosca] Re:[tosca] RE: Re:[tosca] Groups - Issue_TOSCA318_Lack of BPMN BPEL support-v1.0.pptx uploaded 

     





    Hi Luc,
    I think Chirs' suggestion make sense.
    Just like a famous western saying: "Rome wasn't built in a day", it's not realistic to try to work out a "perfect" solution overnight. We need to solve the issue we currently faced and allow it evolve towards the right direction in the same time. I'd like
     to say that there might be a solution close to but not "perfect" solution at all, becasue things always change. 
     
    Furthermore, I don't think exclusive approach is the best choice for workflow. Because there is no a silver bullet to solve all the problems. Just as what I and Claud were saying in the last proposal presentation, there were still some scenarios which tosca
     workflow can't handle with right now, which have already been implemented by BPMN/BPEL in OpenECOMP/OPEN-O/OpenTOSCA.
     
    I will be appreciate if you could kindly agree this approach or you can figure out a better one to address it in a short term.
     
    Thanks,
    Huabing





    Original Mail







    Sender: 
    < luc.boutier@fastconnect.fr > ;



    To:  < lauwers@ubicity.com > ;zhaohuabing10201488;



    CC:  < mrutkows@us.ibm.com > ;
    < tosca@lists.oasis-open.org > ;
    < claude.noshpitz@att.com > ;
    < paul.lipton@ca.com > ;
    < lishitao@huawei.com > ;MengZhaoXing10024238;



    Date:  2017/03/25 04:35



    Subject: Re: [tosca] Re:[tosca] RE: Re:[tosca] Groups - Issue_TOSCA318_Lack of BPMN BPEL support-v1.0.pptx uploaded


     






    Hi Chris,
     
    I see no real difference with this delegate proposal and an operation within the workflow except that  operation
    with artifact type is something we are working  on and could provide portable and normative support.
     
    We can write a TOSCA 1.1 workflow with set_state at the end and a single call to the BPMN artifact  operation, that
    is really similar to what you propose but leveraging  planned 1.2 standard definitions (once we finish the artifact type and artifact executor definition). If not we will end up with a delegate that orchestrator does not know how to handle,  delegate is intended
    for orchestrator provided nodes (matched abstract  nodes – so specific to orchestrator). Or only some specific impl will know how to handle them? And this will be custom per Impl and for no more benefits that the simple artifact support  that we proposed.
     
    Once again, I really think that we should work on instance model and API before we go further. And  also complete
    the work on custom artifact type support because  even this is not fully completed yet and seems on hold since we discuss this BPMN/BPEL elements rather moving forward. I really believe that more than making some people happy we should focus  on trying to
    build a reliable standard. This is exactly why we worked  on the workflow spec in 1.1. because there where nothing people could really rely on in previous spec. Declarative workflows ordering was not clearly defined and saying that multiple workflows  languages
    could be consider was not a reliable statement and actually  just lead us to the point we are now with people making their own choices out of the TC and trying to find a reconciliation rather than moving forward on the multiple challenges we should  address.
     
    I think that in this perspective the work started on artifact type support is critical and we should  complete that
    work rather than trying to solve all issues  and especially elements that will not bring more to TOSCA but just please people (I am still not seeing anything that is TOSCA compliant that cannot be done with the actual workflow language – and  not TOSCA compliant
    elements should currently be supported  through specific artifacts). I still feel on my own that other workflows language will weaken TOSCA as they are not compliant with the TOSCA way to define and call operations and especially the current  artifact type
    work.
     
    That said I don’t say we should not consider the support of specific workflow languages in the future,  I just feel
    that we should not make wrong choices to please  people while some elements are not ready yet in TOSCA.
     
    Anyway, we just don’t agree here I guess,
     
    Luc
     



    From:
    Chris Lauwers
    < lauwers@ubicity.com >



    Date: Friday, 24 March 2017 at 18:29
    To: Luc Boutier
    < luc.boutier@fastconnect.fr > , " zhao.huabing@zte.com.cn "
    < zhao.huabing@zte.com.cn >


    Cc:
    Matthew Rutkowski < mrutkows@us.ibm.com > , " tosca@lists..oasis-open..org "
    < tosca@lists.oasis-open.org > , " claude.noshpitz@att.com "
    < claude.noshpitz@att.com > , Paul Lipton
    < paul.lipton@ca.com > , shitao  li
    < lishitao@huawei.com > , " meng.zhaoxing1@zte.com.cn "
      < meng.zhaoxing1@zte.com.cn >
    Subject: RE: [tosca] Re:[tosca] RE: Re:[tosca] Groups - Issue_TOSCA318_Lack of BPMN BPEL support-v1.0.pptx uploaded

     
    Hi Luc,
     
    While I generally agree with the “walk before you run” approach, I believe there might be a very simple
    way to accommodate  what Huabing wants. How about the following:
     
    1.      
    We already have a “delegate” keyname on workflow activities. What if in addition, we also allowed a “delegate” keyname on a top-level workflow definition? This would  signal
     to the orchestrator (in a standardized way) that the workflow would be taken over entirely by an external entity. The argument of the “delegate” keyname would be the artifact name of the BPNM or BPEL workflow (for which we would obviously still need  to define
     a processor).
    2.      
    I also agree that in order to do this correctly, we will have to standardize an API to the instance model, and more sophisticated TOSCA workflows could benefit from  such  an
    API as well. However, the API available to TOSCA workflows today is limited to “set_state” and “call_operation”. At the very least, we could make those operations available to external workflows, which would put these external workflows on-par with  TOSCA
     workflows.
     
    While this doesn’t entirely address your “portability” concerns, at least it provides a standard way
    for template  designers to signal to the orchestrator that responsibility  for orchestration needs to be delegated to an external workflow engine.

     
    thanks,
     
    Chris
     
     
     


    From: BOUTIER, LUC [mailto: luc.boutier@fastconnect.fr ]

    Sent: Wednesday, March 22, 2017 11:31 PM
    To: Chris Lauwers
    < lauwers@ubicity.com > ;
    zhao.huabing@zte.com.cn
    Cc: mrutkows@us.. ibm.com ;
    tosca@lists.oasis-open.org ;
    claude.noshpitz@att.com ;
    paul.lipton@ca.com ;
    lishitao@huawei.com ;
    meng.zhaoxing1@zte.com.cn
    Subject: Re: [tosca] Re:[tosca] RE: Re:[tosca] Groups - Issue_TOSCA318_Lack of BPMN BPEL support-v1.0.pptx uploaded


     
    Chris, Huabing,
     
    I think that we should not constraint 1.2 on custom workflow support and that we should try to go step by step:
    1.      
    We still don’t have artifact type executors completed and I think this is the first step we need to complete
    2.      
    We still don’t have an instance model
    3.      
    And once instance model is defined we will need also an instance model API to be defined and agreed
     
    Instance model and Instance model APIs are pre-requisite for any kind of workflow extensions are workflow execution
    extensions  will mean workflow engines external to the TOSCA orchestrator,  or there won’t be portability as we cannot expect or have as a pre-requisite for TOSCA orchestrator to support any kind of Workflow languages especially open workflow languages supporting
    extensions  (meaning not supported everywhere).
     
    So, my suggestion is that the 1.2 target should define a way to execute custom operation types in a portable way
    and we need to  have this work completed (this is the great work started  by Chris). BPMN or BPEL in 1.2 will be artifact types with the limitations Chris mentioned.
     
    As we say in France « Il ne faut pas mettre la charrue avant les bœufs »
     
    Luc
     

    From:
    < tosca@lists..oasis-open.org >
    on behalf of Chris Lauwers < lauwers@ubicity.com >



    Date: Thursday, 23 March 2017 at 05:58
    To: " zhao.huabing@zte.com.cn "
    < zhao.huabing@zte.com.cn >
    Cc: Matthew Rutkowski
    < mrutkows@us.ibm.com > , " tosca@lists.oasis-open.org "
    < tosca@lists.oasis-open.org > ,  " claude.noshpitz@att.com "
      < claude.noshpitz@att.com > , Paul Lipton
    < paul.lipton@ca.com > ,  shitao li
    < lishitao@huawei.com > , " meng..zhaoxing1@zte.com.cn "
      < meng.zhaoxing1@zte.com.cn >
    Subject: RE: [tosca] Re:[tosca] RE: Re:[tosca] Groups - Issue_TOSCA318_Lack of BPMN BPEL support-v1.0.pptx uploaded





     
    I’m not sure about the timeframe. Matt should chime in on this.
     
    Thanks,
     
    Chris
     
    From:
    tosca@lists.oasis-open.org [ mailto:tosca@lists.oasis-open.org ]
    On Behalf Of zhao.huabing@zte.com.cn
    Sent: Wednesday, March 22, 2017 9:57 PM
    To: Chris Lauwers
    < lauwers@ubicity.com >
    Cc:
    mrutkows@us.ibm.com ;
    tosca@lists.oasis-open.org ;
    claude.noshpitz@att.com ;
    paul.lipton@ca.com ; lishitao@huawei.com ;
    meng.zhaoxing1@zte.com.cn
    Subject: [tosca] Re:[tosca] RE: Re:[tosca] Groups - Issue_TOSCA318_Lack of BPMN BPEL support-v1.0.pptx uploaded
     





    Hi Chris,
    Thanks for your explanation.
    That's exactly what I'm curious about. 
    So we're planing planning to add arbitrary artifact implementations for the entire workflow of the topology template in 1.2, such as BPMN, BPEL, Node-RED,Ballerina etc.?
     
    Thanks,
    Huabing





    Original Mail







    Sender: 
    < lauwers@ubicity.com > ;



    To:  zhaohuabing10201488;
    < mrutkows@us.ibm.com > ;



    CC:  < tosca@lists.oasis-open.org > ;
    < claude.noshpitz@att.com > ;
    < paul.lipton@ca.com > ;
    < lishitao@huawei.com > ;MengZhaoXing10024238;



    Date:  2017/03/23 12:21



    Subject: [tosca] RE: Re:[tosca] Groups - Issue_TOSCA318_Lack of BPMN BPEL support-v1.0.pptx uploaded


     






    Hi Huabing,
     
    Yes, your understanding of the plan is correct.
     
    However, in the current version of the spec, artifacts can only be used to provide implementations for operations.
    For example,   this means that you will be able to specify  a BPEL workflow to implement the “create” operation on the Standard lifecycle operation.
     
    We currently don’t have a mechanism to use artifacts as implementations for entire workflows. This will need to get
    added in a   later version.
     
    Thanks,
     
    Chris
     
    From:
    zhao.huabing@zte.com.cn [ mailto:zhao.huabing@zte.com.cn ]

    Sent: Tuesday, March 21, 2017 4:41 AM
    To:
    mrutkows@us.ibm.com ; Chris Lauwers < lauwers@ubicity.com >
    Cc:
    tosca@lists.oasis-open.org ;
    claude.noshpitz@att.com ;
    paul.lipton@ca.com ; lishitao@huawei.com ;
    meng.zhaoxing1@zte.com.cn
    Subject: Re:[tosca] Groups - Issue_TOSCA318_Lack of BPMN BPEL support-v1.0.pptx uploaded
     





    Hi Matt, Chris,
     
    I haven't find any update about this in my inbox, did I miss anything?
    I guess the idea is that TOSCA could take BPMN/BPEL as an artifact type and it can be executed by an artifact processor(workflow execution engine) provided by orchestrator, right?
     
    Thanks,
    Huabing
     





    Original Mail







    Sender:  zhaohuabing10201488



    To:  < mrutkows@us.ibm.com > ;
    < lauwers@ubicity.com > ;



    CC:  < tosca@lists.oasis-open.org > ;
    < claude.noshpitz@att.com > ;
    < paul.lipton@ca.com > ;
    < lishitao@huawei.com > ;MengZhaoXing10024238;



    Date:  2017/03/16 09:54



    Subject: Re:[tosca] Groups - Issue_TOSCA318_Lack of BPMN BPEL support-v1.0.pptx uploaded


     






    Hi Matt,
    Thanks for uploading the slide deck.


    Do we have a minutes for this meeting? I'm still improving my English skill, so I have difficulty to get all the points of everyone in this meeting...
    Is the conclusion that we'll incorporate BPMN/BPEL workflow as artifact in the later version of simple YAML and Chris are working on that?
     
    Thanks,
    Huabing
     


     





    Sender: 
    < mrutkows@us.ibm.com > ;



    To:  < tosca@lists.oasis-open.org > ;



    Date:  2017/03/15 23:16



    Subject: [tosca] Groups - Issue_TOSCA318_Lack of BPMN BPEL support-v1.0.pptx uploaded


     

    Submitter's message
            Parts of these slides were presented during the 2017-03-14 Simple Profile WG meeting.        

    -- Mr. Matthew Rutkowski





    Document Name :

    Issue_TOSCA318_Lack of BPMN BPEL support-v1.0.pptx
           







    No description provided...        
           
    Download Latest Revision
           
    Public Download Link
           







    Submitter : Mr. Matthew Rutkowski
                    Group : OASIS Topology and Orchestration Specification for Cloud Applications (TOSCA) TC
            Folder : Working Documents
            Date submitted : 2017-03-15 08:15:37
                   
               





     




     



     




     



     




     



     




     



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  • 3.  Re: [tosca] Re:[tosca] RE: Re:[tosca] Groups - Issue_TOSCA318_Lack of BPMN BPEL support-v1.0.pptx uploaded

    Posted 04-08-2017 06:57




    Hi Chris, Micheal,
     
    Just quick comment on your points 2 and 3: TOSCA imperative workflows are actually partially model driven as they are defined at the template level and not instance
    level, without TOSCA model they don’t mean a lot and on the other hand that is why they suits the TOSCA world.
     
    Luc
     

    From:
    Chris Lauwers <lauwers@ubicity.com>
    Date: Friday, 7 April 2017 at 23:17
    To: Michael Brenner <michael@gigaspaces.com>, "zhao.huabing@zte.com.cn" <zhao.huabing@zte.com.cn>
    Cc: Luc Boutier <luc.boutier@fastconnect.fr>, Matthew Rutkowski <mrutkows@us.ibm.com>, "tosca@lists.oasis-open.org" <tosca@lists.oasis-open.org>, "claude.noshpitz@att.com" <claude.noshpitz@att.com>, Paul Lipton <paul.lipton@ca.com>, shitao li <lishitao@huawei.com>,
    "meng.zhaoxing1@zte.com.cn" <meng.zhaoxing1@zte.com.cn>, Nati Shalom <natis@gigaspaces.com>, Arthur Berezin <arthur@gigaspaces.com>, Amir Levy <amir@gigaspaces.com>, Sivan Barzily <sivan@gigaspaces.com>, Tal Liron <tal@gigaspaces.com>
    Subject: RE: [tosca] Re:[tosca] RE: Re:[tosca] Groups - Issue_TOSCA318_Lack of BPMN BPEL support-v1.0.pptx uploaded


     

    Hi Michael,
     
    Thanks for your detailed write-up. When you finish your document on this topic, I’d love to get a copy.
     
    A couple of comments:
     

    1.      
    I agree with your Day 1 vs. Day 2 distinction. TOSCA so far has focused primarily on Day 1 deployments, but in my opinion the real value is in Day 2 operations. I believe this will require
    more progress on “instance models” that capture operational state, since the Day 2 workflows you mentioned are really implementation of autonomic processes that manipulate  “operational state”.


    2.      
    I also agree with your distinction between “model-driven” vs. “task-driven” approaches to workflows. In fact, the TOSCA spec owes up to this distinction by specifying both “imperative”
    and “declarative” workflows. Declarative workflows are created automatically by the orchestrators, whereas imperative workflows must be specified by the service template designer using the workflow language introduced in TOSCA Simple Profile for YAML v1.1.
    Declarative workflows in TOSCA don’t require service template designers to specify any workflow at all: the “declarative” workflow is derived automatically by the orchestrator by leveraging implementations (“artifacts”) of operations that are part of the standard
    lifecycle management interfaces.

    3.      
    From that point-of-view, the question whether to use TOSCA’s imperative workflow language or BPEL or BPMN is actually a valid question, in my opinion, because either one could be used
    to specify “imperative” workflows. The advantage of TOSCA’s built-in workflow language is obviously that it integrates better with the rest of TOSCA, whereas more work is need to allow external workflow engines to operate on TOSCA models.

    4.      
    The real question we should focus on, then, (and you alluded to this as well) is why there should be a need to use imperative workflows at all? What are the use cases that cannot be
    solved using declarative workflows and require imperative workflows instead? I would much rather focus our energy on answering this question, since it will lead to improvements to the language that will make declarative workflows more flexible and more widely
    applicable.

    5.      
    I’ve given some thought to the types of extensions that may be required to make declarative workflows more usable. The following come to mind:


    a.       
    Introduce interface-specific state variables. We currently assume that there is one node state variable that captures lifecycle management state for that node. For other types of interfaces
    (such as your healing or scaling interfaces), this state is not useful. We either need additional state values, or additional state variables, or both. The best solution, in my opinion, is to move the state variable into the interface.

    b.      
    Introduce additional metadata for lifecycle operations. For example: what are the pre-conditions that need to be met before the operation can be executed (e.g. what state does the node/interface
    need to be in?). Are there any side effects to the operation (e.g. node/interface transitions into a different state). Such metadata is currently supported in the TOSCA imperative workflow, but in my opinion much of this belongs with the operations themselves,
    not with the workflow.

    c.       
    Introduce additional metadata for interfaces themselves. For example: relationship interfaces currently don’t allow the interface type designer to specify any ordering relationships
    between operations called on source node vs. operations called on target nodes. Instead, orchestrators are supposed to know the proper ordering for the normative relationship types. This means that it is not possible to introduce custom relationship interfaces
    without also specifying a declarative workflow.  We need some type of mechanism for specifying operations ordering.

     
    I look forward to further discussion about this topic.
     
    Thanks,
     
    Chris
     
     
    From: Michael Brenner [mailto:michael@gigaspaces.com]

    Sent: Tuesday, March 28, 2017 5:54 PM
    To: zhao.huabing@zte.com.cn
    Cc: BOUTIER, LUC <luc.boutier@fastconnect.fr>; Chris Lauwers <lauwers@ubicity.com>; Matt Rutkowski <mrutkows@us.ibm.com>; tosca@lists.oasis-open.org; claude.noshpitz@att.com; Lipton, Paul C <paul.lipton@ca.com>; Lishitao <lishitao@huawei.com>; meng.zhaoxing1@zte.com.cn;
    Nati Shalom <natis@gigaspaces.com>; Arthur Berezin <arthur@gigaspaces.com>; Amir Levy <amir@gigaspaces.com>; Sivan Barzily <sivan@gigaspaces.com>; Tal Liron <tal@gigaspaces.com>
    Subject: Re: [tosca] Re:[tosca] RE: Re:[tosca] Groups - Issue_TOSCA318_Lack of BPMN BPEL support-v1.0.pptx uploaded
     

    Hi all,

     


    First of, I would like to apologize for joining this thread just now.



    The fact of the matter is that we felt this is an important discussion and decision and therefore we needed to invest more time analyzing the current proposal and impact of supporting BPMN/BPML/BPEL.


     


    In general I think that Luc did a great job both in the 1.1 proposal and also by outlining the general approach on how we should handle workflows in TOSCA in order to allow better portability
    and at the same time make it simple.


     


    I would like to start with something that I feel we all may be correct in some way, but the solution often depends on the context. In this case, different approaches may be related to what each
    of us mean by "workflow". Like in many other cases, it is an overloaded term. I don't think we want to get into an academical debate and spend huge efforts in creating a common definition, but if we could accept a definition and use case for workflow it would
    be easier to discuss the potential benefit or disadvantages of integrating BPMN/BPML/BPEL into this model.


     


    Recently I started collecting various perspectives and putting together an analysis on this topic (rough Draft at this point, but it will posted soon and I will be ready to share with those interested).


     


    I would like to quote specifically the workflow definition as it provides an important framing for this discussion:


     


    <snip>


    DevOps Workflow:


    Workflow is an orchestrated and repeatable pattern representing an execution plan expressed as a directed graph of tasks
    – simple to define, to reason, to execute and to visualize.


    DevOps workflow are used to orchestrate operations in infrastructure and applications, automate complex CI/CD processes etc.
     

    A typical use case for DevOps workflow include “Day 0” operations such as Install/uninstall workflow - execute the lifecycle operation of an application
    and its associated infrastructure.
     

    Things get vastly more complex in case of workflow that deal processes that need to update/change an existing deployment, based on “Day 2” operations.
    A typical set of workflows that fits into this category includes:
     

    ·  
    Heal workflow - fix a failed node (typically by re-executing the failed node lifecycle operation and relationship)

    ·  
    Scale workflow - increase the capacity of a given application node (typically by executing the lifecycle operation
    of the target node multiple time on each scale instance)

    ·  
    Update workflow - a common pattern for update is referred to as blue/green. (A typical implementation includes
    taking a snapshot of the current state -> pushing the new update -> redirecting traffic to the new deployment -> gradually redirect all traffic to the new version -> if failed roll-back to the previous version)

    ·  
    Topology update (aka as blueprint update) - adding/removing an entire service from and existing application topology.
    A typical implementation includes comparing the new blueprint with the existing version->identifying the changes -> executing the changes and updating the model accordingly.
     

    There are basically two main approaches for workflow execution: a task-based approach vs a model-driven approach.

    In a task-based system we execute a workflow by breaking it into a specific set of tasks. For example let’s imagine a simple use case of installing
    a nodeJS instance on a virtual machine.

    The workflow for that task include the following steps:
     

    1.      
    Provision the VM

    2.      
    Setup network (public/private IP, security group etc)

    3.      
    Install and configure the nodeJS instance

    4.      
    Start the nodeJS instance
     

    In a task-based system I will need to map every step as a task and execute it.
     

    In a model-driven approach I would define the model first. The workflow execution will be driven from the model and would be generated implicitly.

    The Core Components of a model-driven workflow are:
     

    ·  
    Model (Graph) - describes the nodes and their relationship

    ·  
    State - maintain the actual state of execution of each node.


    ·  
    Execution - the actual code that maps to the specific lifecycle operation of each node.
     

    The key differences between a model-driven and task-driven approach is that task-driven approach tends to be purpose-built (allows for more specificity,
    but less re-usability) while the model-driven approach lends itself to be more tend to be more generic/flexible

    In other words, a model-driven workflow is simpler to change as it groups the tasks into their respective node-types and thus provide more coarse-grain
    building blocks that are easier to change and maintain. It’s also easier to read and follow and fits better with a designer task.

    <snip>

    I am sure you guessed that the task-based approach is exemplified by BPMN/BPML/BPEL, and the model-driven approach is exemplified by the TOSCA-native approach to workflows.


     


    I would also like to end with the conclusion that we see from that analysis:


     


    <snip>


    Conclusion:



    In conclusion, the turn-around in TOSCA towards the declarative, model-driven approach for workflows is a very positive move, and will help TOSCA
    to have “a good year in 2017”. There is really nothing wrong with using BPMN/BPML/BPEL, where appropriate. But there is something to be said when we try to use a complex specification designed for a different set of applications, in a domain where an approach
    that is simple, flexible, re-usable fits better, and the word is “overkill”.


    So let’s support the “good year of TOSCA” initiative by embracing the TOSCA_YAML_V1.1 approach , and focus on the progress of the improved TOSCA_YAML_V1.2,
    and future versions planned!"

    <snip>

    Thanks all for your patience in reading my lengthy response; I am looking forward to continue staying engaged until we find the right solution for the problem space.

     

    Best regards,

    Michael





     

    On Mon, Mar 27, 2017 at 6:57 AM, < zhao.huabing@zte.com.cn > wrote:


    Hi Luc,
    Please see my inline comments.
     
    Thanks,
    Huabing



    Original Mail




    Sender: 
    < luc.boutier@fastconnect.fr > ;


    To:  zhaohuabing10201488;


    CC: 
    < lauwers@ubicity.com > ;
    < mrutkows@us.ibm.com > ;
    < tosca@lists.oasis-open.org > ;
    < claude.noshpitz@att.com > ;
    < paul.lipton@ca.com > ;
    < lishitao@huawei.com > ;MengZhaoXing10024238;


    Date:  2017/03/27 16:10


    Subject: Re: [tosca] Re:[tosca] RE: Re:[tosca] Groups - Issue_TOSCA318_Lack of BPMN BPEL support-v1.0.pptx uploaded 


     


    Hi Huabing,
     
    I realized you made your own choices out of the TC and really want them to be standard now. 
    Huabing: I didn't mea that(make my own choices), It's the intention of broader audience/users of
    TOSCA (Service Provider:AT&T, CMCC, Vendor:Huawei, ZTE and research group:University of Stuttgart) to keep BPMN/BPEL in TOSCA, based on their own experiences and requirements, I think we all have heard their concerns in the proposal presentation and open comments
    maillist.   Also I thought it's the conclusion of the last meeting that I've confirmed by mails.
     
    You are talking a lot about scenarios that cannot be done with current  TOSCA but I still don’t see them to be honest. I think
    that current workflow + artifact types/artifact type executors can do everything, even manual operations as you can make an artifact type/artifact type executor that will prompt user. It’s just that it  follows a TOSCA compliant way to do so, and compliant
    in 2 ways:
    -          
    Can be triggered through imperative workflows
    -          
    Can be included in a declarative generated workflow (this is critical as this is kind of the goal of TOSCA).
    BPMN taks are not defined on TOSCA nodes and cannot be triggered through declarative generated workflows. This is again why it’s
    not a good target for TOSCA and  for what we try to achieve.
      Huabing: Ideally, yes, we can add everything which not inside TOSCA in term of an artifact.
    But it imply that we have to implement another "Workflow execution Engine" which has the similar functionalities of an arbitrary mature workflow execution engine, in a different way, which would be a lot of work and it's not the main goal of orchestration.
    You asked for better choice we already provided one:
    -          
    artifact type approach is absolutely valid and allow to have both portability kept and BPMN execution possible, so this is to me the better approach  that we BTW agreed on on the calls. Not sure you
    understood what I write in my previous email but I feel that delegate or artifact type are quite the same thing here.
    And no, I’m not in favour of losing portability again, and to be honest not in favour of supporting any workflow languages as
    long as we don’t have a way to make  it portable (I mean internally do what you want and as I explained already you can use internally a BPMN engine to process your TOSCA, that is your choice).
     
    I think that TOSCA exists for quite a long time now and we didn’t had really portability, right now every implementer made their
    own choices (that’s what you  did, that’s what GigaSpaces did, that’s also what we did in our tool – for the yet not fully standardize custom artifact executions). Based on that I feel that there is 2 path for TOSCA:
    -          
    Stop trying to solve the execution issue and be just a modelling language (drop interfaces and operations) and let people provide imperative specific  means to make things executed through other specs
    (BPMN etc.) or other means (Docker compose, Kubernetes models or other declarative approaches that comes).
    -          
    Keep trying to address the initial challenge which is to try to build a portable declarative and executable standard (well that’s quick sentence but  I think it was the main points of TOSCA somehow).
    So I’m sorry but no I cannot kindly agree with something that I really feels as a wrong path. That said if I’m the only one to
    feel that way please let me know  as we should probably stop a lot of work we started here (including artifact type executor and let people just do their own custom non portable things).
    Huabing: What we're asking is not an "A" or  "B" choice for workflow standard, instead, we'd like to keep workflow
    choice open so the implementation could choose whatever workflow which make sense based on their requirement. So we don't have to stop what we're working on right now to incorporate BPMN/BPEL into TOSCA.


    Luc
     

    From:
    " zhao.huabing@zte.com.cn "
    < zhao.huabing@zte.com.cn >
    Date: Monday, 27 March 2017 at 04:44
    To: Luc Boutier
    < luc.boutier@fastconnect.fr >
    Cc: Chris Lauwers
    < lauwers@ubicity.com > ,
    Matthew Rutkowski < mrutkows@us.ibm.com > ,
    " tosca@lists.oasis-open.org "
    < tosca@lists.oasis-open.org > ,
    " claude.noshpitz@att.com "
    < claude.noshpitz@att.com > ,
    Paul Lipton < paul.lipton@ca.com > ,
    shitao li < lishitao@huawei.com > ,
     " meng.zhaoxing1@zte.com.cn "
    < meng.zhaoxing1@zte.com.cn >
    Subject: Re: [tosca] Re:[tosca] RE: Re:[tosca] Groups - Issue_TOSCA318_Lack of BPMN BPEL support-v1.0.pptx uploaded 

     





    Hi Luc,
    I think Chirs' suggestion make sense.
    Just like a famous western saying: "Rome wasn't built in a day", it's not realistic to try to work out a "perfect" solution overnight. We need to solve the issue we currently faced and allow it evolve towards the right direction in the same time. I'd like
     to say that there might be a solution close to but not "perfect" solution at all, becasue things always change. 
     
    Furthermore, I don't think exclusive approach is the best choice for workflow. Because there is no a silver bullet to solve all the problems. Just as what I and Claud were saying in the last proposal presentation, there were still some scenarios which tosca
     workflow can't handle with right now, which have already been implemented by BPMN/BPEL in OpenECOMP/OPEN-O/OpenTOSCA.
     
    I will be appreciate if you could kindly agree this approach or you can figure out a better one to address it in a short term.
     
    Thanks,
    Huabing





    Original Mail







    Sender: 
    < luc.boutier@fastconnect.fr > ;



    To:  < lauwers@ubicity.com > ;zhaohuabing10201488;



    CC:  < mrutkows@us.ibm.com > ;
    < tosca@lists.oasis-open.org > ;
    < claude.noshpitz@att.com > ;
    < paul.lipton@ca.com > ;
    < lishitao@huawei.com > ;MengZhaoXing10024238;



    Date:  2017/03/25 04:35



    Subject: Re: [tosca] Re:[tosca] RE: Re:[tosca] Groups - Issue_TOSCA318_Lack of BPMN BPEL support-v1.0.pptx uploaded


     






    Hi Chris,
     
    I see no real difference with this delegate proposal and an operation within the workflow except that  operation with artifact
    type is something we are working  on and could provide portable and normative support.
     
    We can write a TOSCA 1.1 workflow with set_state at the end and a single call to the BPMN artifact  operation, that is really
    similar to what you propose but leveraging  planned 1.2 standard definitions (once we finish the artifact type and artifact executor definition). If not we will end up with a delegate that orchestrator does not know how to handle,  delegate is intended for
    orchestrator provided nodes (matched abstract  nodes – so specific to orchestrator). Or only some specific impl will know how to handle them? And this will be custom per Impl and for no more benefits that the simple artifact support  that we proposed.
     
    Once again, I really think that we should work on instance model and API before we go further. And  also complete the work on
    custom artifact type support because  even this is not fully completed yet and seems on hold since we discuss this BPMN/BPEL elements rather moving forward. I really believe that more than making some people happy we should focus  on trying to build a reliable
    standard. This is exactly why we worked  on the workflow spec in 1.1. because there where nothing people could really rely on in previous spec. Declarative workflows ordering was not clearly defined and saying that multiple workflows  languages could be consider
    was not a reliable statement and actually  just lead us to the point we are now with people making their own choices out of the TC and trying to find a reconciliation rather than moving forward on the multiple challenges we should  address.
     
    I think that in this perspective the work started on artifact type support is critical and we should  complete that work rather
    than trying to solve all issues  and especially elements that will not bring more to TOSCA but just please people (I am still not seeing anything that is TOSCA compliant that cannot be done with the actual workflow language – and  not TOSCA compliant elements
    should currently be supported  through specific artifacts). I still feel on my own that other workflows language will weaken TOSCA as they are not compliant with the TOSCA way to define and call operations and especially the current  artifact type work.
     
    That said I don’t say we should not consider the support of specific workflow languages in the future,  I just feel that we should
    not make wrong choices to please  people while some elements are not ready yet in TOSCA.
     
    Anyway, we just don’t agree here I guess,
     
    Luc
     



    From:
    Chris Lauwers
    < lauwers@ubicity.com >



    Date: Friday, 24 March 2017 at 18:29
    To: Luc Boutier
    < luc.boutier@fastconnect.fr > , " zhao.huabing@zte.com.cn "
    < zhao.huabing@zte.com.cn >


    Cc: Matthew Rutkowski
    < mrutkows@us.ibm.com > , " tosca@lists..oasis-open..org "
    < tosca@lists.oasis-open.org > , " claude.noshpitz@att.com "
    < claude.noshpitz@att.com > , Paul Lipton
    < paul.lipton@ca.com > , shitao  li
    < lishitao@huawei.com > , " meng.zhaoxing1@zte.com.cn "
      < meng.zhaoxing1@zte.com.cn >
    Subject: RE: [tosca] Re:[tosca] RE: Re:[tosca] Groups - Issue_TOSCA318_Lack of BPMN BPEL support-v1.0.pptx uploaded

     
    Hi Luc,
     
    While I generally agree with the “walk before you run” approach, I believe there might be a very simple way to accommodate
     what Huabing wants. How about the following:
     
    1.      
    We already have a “delegate” keyname on workflow activities. What if in addition, we also allowed a “delegate” keyname on a top-level workflow definition? This would  signal  to the orchestrator
    (in a standardized way) that the workflow would be taken over entirely by an external entity. The argument of the “delegate” keyname would be the artifact name of the BPNM or BPEL workflow (for which we would obviously still need  to define  a processor).
    2.      
    I also agree that in order to do this correctly, we will have to standardize an API to the instance model, and more sophisticated TOSCA workflows could benefit from  such  an API as well.
    However, the API available to TOSCA workflows today is limited to “set_state” and “call_operation”. At the very least, we could make those operations available to external workflows, which would put these external workflows on-par with  TOSCA  workflows.
     
    While this doesn’t entirely address your “portability” concerns, at least it provides a standard way for template
     designers to signal to the orchestrator that responsibility  for orchestration needs to be delegated to an external workflow engine.

     
    thanks,
     
    Chris
     
     
     


    From: BOUTIER, LUC [mailto: luc.boutier@fastconnect.fr ]

    Sent: Wednesday, March 22, 2017 11:31 PM
    To: Chris Lauwers
    < lauwers@ubicity.com > ;
    zhao.huabing@zte.com.cn
    Cc: mrutkows@us.. ibm.com ;
    tosca@lists.oasis-open.org ;
    claude.noshpitz@att.com ;
    paul.lipton@ca.com ;
    lishitao@huawei.com ;
    meng.zhaoxing1@zte.com.cn
    Subject: Re: [tosca] Re:[tosca] RE: Re:[tosca] Groups - Issue_TOSCA318_Lack of BPMN BPEL support-v1.0.pptx uploaded


     
    Chris, Huabing,
     
    I think that we should not constraint 1.2 on custom workflow support and that we should try to go step by step:
    1.      
    We still don’t have artifact type executors completed and I think this is the first step we need to complete
    2.      
    We still don’t have an instance model
    3.      
    And once instance model is defined we will need also an instance model API to be defined and agreed
     
    Instance model and Instance model APIs are pre-requisite for any kind of workflow extensions are workflow execution extensions
     will mean workflow engines external to the TOSCA orchestrator,  or there won’t be portability as we cannot expect or have as a pre-requisite for TOSCA orchestrator to support any kind of Workflow languages especially open workflow languages supporting extensions
     (meaning not supported everywhere).
     
    So, my suggestion is that the 1.2 target should define a way to execute custom operation types in a portable way and we need to
     have this work completed (this is the great work started  by Chris). BPMN or BPEL in 1.2 will be artifact types with the limitations Chris mentioned.
     
    As we say in France « Il ne faut pas mettre la charrue avant les bœufs »
     
    Luc
     

    From:
    < tosca@lists..oasis-open.org >
    on behalf of Chris Lauwers < lauwers@ubicity.com >



    Date: Thursday, 23 March 2017 at 05:58
    To: " zhao.huabing@zte.com.cn "
    < zhao.huabing@zte.com.cn >
    Cc: Matthew Rutkowski
    < mrutkows@us.ibm.com > , " tosca@lists.oasis-open.org "
    < tosca@lists.oasis-open.org > ,  " claude.noshpitz@att.com "
      < claude.noshpitz@att.com > , Paul Lipton
    < paul.lipton@ca.com > ,  shitao li
    < lishitao@huawei.com > , " meng..zhaoxing1@zte.com.cn "
      < meng.zhaoxing1@zte.com.cn >
    Subject: RE: [tosca] Re:[tosca] RE: Re:[tosca] Groups - Issue_TOSCA318_Lack of BPMN BPEL support-v1.0.pptx uploaded





     
    I’m not sure about the timeframe. Matt should chime in on this.
     
    Thanks,
     
    Chris
     
    From:
    tosca@lists.oasis-open.org [ mailto:tosca@lists.oasis-open.org ]
    On Behalf Of zhao.huabing@zte.com.cn
    Sent: Wednesday, March 22, 2017 9:57 PM
    To: Chris Lauwers
    < lauwers@ubicity.com >
    Cc:
    mrutkows@us.ibm.com ;
    tosca@lists.oasis-open.org ;
    claude.noshpitz@att.com ;
    paul.lipton@ca.com ; lishitao@huawei.com ;
    meng.zhaoxing1@zte.com.cn
    Subject: [tosca] Re:[tosca] RE: Re:[tosca] Groups - Issue_TOSCA318_Lack of BPMN BPEL support-v1.0.pptx uploaded
     





    Hi Chris,
    Thanks for your explanation.
    That's exactly what I'm curious about. 
    So we're planing planning to add arbitrary artifact implementations for the entire workflow of the topology template in 1.2, such as BPMN, BPEL, Node-RED,Ballerina etc.?
     
    Thanks,
    Huabing





    Original Mail







    Sender: 
    < lauwers@ubicity.com > ;



    To:  zhaohuabing10201488;
    < mrutkows@us.ibm.com > ;



    CC:  < tosca@lists.oasis-open.org > ;
    < claude.noshpitz@att.com > ;
    < paul.lipton@ca.com > ;
    < lishitao@huawei.com > ;MengZhaoXing10024238;



    Date:  2017/03/23 12:21



    Subject: [tosca] RE: Re:[tosca] Groups - Issue_TOSCA318_Lack of BPMN BPEL support-v1.0.pptx uploaded


     






    Hi Huabing,
     
    Yes, your understanding of the plan is correct.
     
    However, in the current version of the spec, artifacts can only be used to provide implementations for operations. For example,
      this means that you will be able to specify  a BPEL workflow to implement the “create” operation on the Standard lifecycle operation.
     
    We currently don’t have a mechanism to use artifacts as implementations for entire workflows. This will need to get added in a
      later version.
     
    Thanks,
     
    Chris
     
    From:
    zhao.huabing@zte.com.cn [ mailto:zhao.huabing@zte.com.cn ]

    Sent: Tuesday, March 21, 2017 4:41 AM
    To:
    mrutkows@us.ibm.com ; Chris Lauwers < lauwers@ubicity.com >
    Cc:
    tosca@lists.oasis-open.org ;
    claude.noshpitz@att.com ;
    paul.lipton@ca.com ; lishitao@huawei.com ;
    meng.zhaoxing1@zte.com.cn
    Subject: Re:[tosca] Groups - Issue_TOSCA318_Lack of BPMN BPEL support-v1.0.pptx uploaded
     





    Hi Matt, Chris,
     
    I haven't find any update about this in my inbox, did I miss anything?
    I guess the idea is that TOSCA could take BPMN/BPEL as an artifact type and it can be executed by an artifact processor(workflow execution engine) provided by orchestrator, right?
     
    Thanks,
    Huabing
     





    Original Mail







    Sender:  zhaohuabing10201488



    To:  < mrutkows@us.ibm.com > ;
    < lauwers@ubicity.com > ;



    CC:  < tosca@lists.oasis-open.org > ;
    < claude.noshpitz@att.com > ;
    < paul.lipton@ca.com > ;
    < lishitao@huawei.com > ;MengZhaoXing10024238;



    Date:  2017/03/16 09:54



    Subject: Re:[tosca] Groups - Issue_TOSCA318_Lack of BPMN BPEL support-v1.0.pptx uploaded


     






    Hi Matt,
    Thanks for uploading the slide deck.


    Do we have a minutes for this meeting? I'm still improving my English skill, so I have difficulty to get all the points of everyone in this meeting...
    Is the conclusion that we'll incorporate BPMN/BPEL workflow as artifact in the later version of simple YAML and Chris are working on that?
     
    Thanks,
    Huabing
     


     





    Sender: 
    < mrutkows@us.ibm.com > ;



    To:  < tosca@lists.oasis-open.org > ;



    Date:  2017/03/15 23:16



    Subject: [tosca] Groups - Issue_TOSCA318_Lack of BPMN BPEL support-v1.0.pptx uploaded


     

    Submitter's message
            Parts of these slides were presented during the 2017-03-14 Simple Profile WG meeting.        

    -- Mr. Matthew Rutkowski





    Document Name :

    Issue_TOSCA318_Lack of BPMN BPEL support-v1.0.pptx
           







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    Submitter : Mr. Matthew Rutkowski
                    Group : OASIS Topology and Orchestration Specification for Cloud Applications (TOSCA) TC
            Folder : Working Documents
            Date submitted : 2017-03-15 08:15:37
                   
               





     




     



     




     



     




     



     




     



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