Great: we are in agreement :-))
Best regards,
Frank
2016-06-20 9:05 GMT+02:00 Vinod Kavinda <vi...@wso2.com>:
> Hi Frank,
> Agreed for the both suggestions.
>
> As Nandika mentioned "Not accepting a change in the substitute" is the
> option we also decided, whenever we have the ability to do so. But there
> are situations that we cannot do this when the cyclic situation arisen due
> to a time event. Theoratically, we don't have anyone to assign this task at
> this point, so it has to go back to Business Administrator as you suggested.
>
> However, in Activiti the corresponding role is "Task Owner". We will have
> to assign to task owner in this situation. One issue is the task owner is
> optional. Only in such a situation(no owner), we will have to make the task
> Claimable/Unreserved.
>
> Regards,
> Vinod
>
> On Mon, Jun 20, 2016 at 10:48 AM, Nandika Jayawardana <nand...@wso2.com>
> wrote:
>
>> Hi Frank,
>>
>> Not accepting a change in the substitute when there is a cyclic situation
>> is the options we decided as well.
>>
>> Regards
>> Nandika
>>
>> On Fri, Jun 17, 2016 at 11:26 PM, Frank Leymann <fr...@wso2.com> wrote:
>>
>>> Hi Vinod,
>>>
>>> Whenever a user changes his/her substitute, we check for a circular
>>> dependency. This check happens independent of the fact whether substitutes
>>> are defined when the user are created ("modeling time") or when the
>>> substitute of a user is changed during "runtime". Is that your
>>> understanding too?
>>>
>>> If a circular dependency is detected, the request for the new substitute
>>> is not accepted. And, yes, that's problematic because it may become quite
>>> cumbersome or even impossible to find a possible substitute (i.e. one that
>>> our cycle checker will accept). For example, in case of n users U1,
>>> U2,...,Un user Ui has substitute Si and Si = U(i+1) with U(n+1)=U1 - we
>>> have a problem. During modeling time their may be time to fix the problem,
>>> but during runtime that may be critical. Setting the Reserved or
>>> inProgress tasks of the user just defining his new substitute in state
>>> Ready doesn't help because there may be no potential owners who may get
>>> aware about the task.
>>>
>>> For this purpose, the key principle of Human Task is that the engine
>>> must do everything to push tasks to (at least) Reserve status. This is done
>>> by corresponding deadline processing, or by nomination: i.e. the engine
>>> informs the Business Administrator of the task who then assigns the task to
>>> an owner. But this may result in a burden of the Business Administrator in
>>> case he will get many tasks to nominate.
>>>
>>> So, let's discuss. My current preference is to *not accept* a change in
>>> the substitute definition in case a cyclic structure would result. WDYT?
>>>
>>>
>>>
>>> Best regards,
>>> Frank
>>>
>>> 2016-06-16 3:31 GMT+02:00 Vinod Kavinda <vi...@wso2.com>:
>>>
>>>> Hi Frank,
>>>> Yes, it's when changing the substitute user. We have to use the second
>>>> suggestion also.
>>>>
>>>> In a scenario where substitution starts in a future time(not just after
>>>> changing the substitute user), we do not have the option of rejecting the
>>>> substitution request. In such a scenario, we will have to make his tasks
>>>> unclaimed!
>>>>
>>>> Regards,
>>>> Vinod
>>>> On Jun 16, 2016 2:28 AM, "Frank Leymann" <fr...@wso2.com> wrote:
>>>>
>>>> Hi Vinod,
>>>>
>>>> yes, that's a well-known issue :-) I suggest to adopt your first
>>>> suggestion, namely checking circular dependencies when a new substitute has
>>>> been specified (I guess that's what you meant - not when adding a new user,
>>>> right?).
>>>>
>>>>
>>>>
>>>> Best regards,
>>>> Frank
>>>>
>>>> 2016-06-15 13:25 GMT+02:00 Vinod Kavinda <vi...@wso2.com>:
>>>>
>>>>> Hi all,
>>>>> I ran into an issue while implementing this.
>>>>>
>>>>> What if we ran into a *circular dependency between user substitutes*?
>>>>> We can't calculate a transitive substitute in this scenario. No one will
>>>>> be
>>>>> available to take up the tasks of the unavailable user.
>>>>>
>>>>> Here is my suggestion for this:
>>>>>
>>>>> *Circular dependency detected while adding a new user*
>>>>> We abort this user addition and reply back to the user asking for a
>>>>> new substitute.
>>>>>
>>>>> *Circular dependency detected while resolving transitive subs in a
>>>>> scheduled event (Due to a user's substitution starting at this point )*
>>>>>
>>>>> Mark the transitive sub is "UNDEFINED". Future tasks that are
>>>>> assigning to this user will be reverted back as unclaimed tasks (remove
>>>>> the
>>>>> assignee).
>>>>>
>>>>> Any suggestions?
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> On Thu, Jun 9, 2016 at 8:31 AM, Vinod Kavinda <vi...@wso2.com> wrote:
>>>>>
>>>>>> Hi Frank,
>>>>>> Agreed.
>>>>>> I have created Jira [1] to track this improvement after the Human
>>>>>> Task integration with BPMN engine.
>>>>>>
>>>>>> [1] - https://wso2.org/jira/browse/BPS-1043
>>>>>>
>>>>>> Regards,
>>>>>> Vinod
>>>>>>
>>>>>> On Wed, Jun 8, 2016 at 10:03 PM, Nandika Jayawardana <
>>>>>> nand...@wso2.com> wrote:
>>>>>>
>>>>>>> Yes, Once the task engine refactoring is complete, we can integrate
>>>>>>> our own task implementation with activiti . Then we can overcome the
>>>>>>> current limitations of user tasks.
>>>>>>>
>>>>>>> Regards
>>>>>>> Nandika
>>>>>>>
>>>>>>> On Wed, Jun 8, 2016 at 7:18 PM, Milinda Perera <milin...@wso2.com>
>>>>>>> wrote:
>>>>>>>
>>>>>>>>
>>>>>>>> On Wed, Jun 8, 2016 at 6:49 PM, Frank Leymann <fr...@wso2.com>
>>>>>>>> wrote:
>>>>>>>>
>>>>>>>>> Dear Vinod,
>>>>>>>>>
>>>>>>>>> understood. My recommendation is that we should argue as long as
>>>>>>>>> possible independent from a certain implementation: if we may decide
>>>>>>>>> to
>>>>>>>>> move from Activiti to Camunda, we should have the architecture/design
>>>>>>>>> right
>>>>>>>>> to port our implementation with minimal effort. That's why I argue in
>>>>>>>>> terms
>>>>>>>>> of the BPMN recommended state model, and when we agree on the
>>>>>>>>> principles we
>>>>>>>>> can map it to the underlying engine. Does this sound acceptable?
>>>>>>>>>
>>>>>>>>> Which brings up the following question: When we support User
>>>>>>>>> Tasks in Activiti, don't we use our HumanTask implementation as User
>>>>>>>>> Task
>>>>>>>>> as BPMN 2.0 assumes? But we use the simplified implementation that
>>>>>>>>> Activiti
>>>>>>>>> ships? If we do the latter, what is our strategy of our HumanTask
>>>>>>>>> implementation?
>>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> +1, Soon or Later I think replacing Activiti User Task or
>>>>>>>> introducing as a new type of user task, with our WS-HumanTask it the
>>>>>>>> best
>>>>>>>> option.
>>>>>>>> AFAIR similar idea is in our future roadmap @Hasitha @Nandika :
>>>>>>>> isn't it?
>>>>>>>>
>>>>>>>> --
>>>>>>>> Milinda Perera
>>>>>>>> Software Engineer;
>>>>>>>> WSO2 Inc. http://wso2.com ,
>>>>>>>> Mobile: (+94) 714 115 032
>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> --
>>>>>>> Nandika Jayawardana
>>>>>>> WSO2 Inc ; http://wso2.com
>>>>>>> lean.enterprise.middleware
>>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> --
>>>>>> Vinod Kavinda
>>>>>> Software Engineer
>>>>>> *WSO2 Inc. - lean . enterprise . middleware <http://www.wso2.com>.*
>>>>>> Mobile : +94 (0) 712 415544
>>>>>> Blog : http://soatechflicks.blogspot.com/
>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>> --
>>>>> Vinod Kavinda
>>>>> Software Engineer
>>>>> *WSO2 Inc. - lean . enterprise . middleware <http://www.wso2.com>.*
>>>>> Mobile : +94 (0) 712 415544
>>>>> Blog : http://soatechflicks.blogspot.com/
>>>>>
>>>>>
>>>>
>>>
>>
>>
>> --
>> Nandika Jayawardana
>> WSO2 Inc ; http://wso2.com
>> lean.enterprise.middleware
>>
>
>
>
> --
> Vinod Kavinda
> Software Engineer
> *WSO2 Inc. - lean . enterprise . middleware <http://www.wso2.com>.*
> Mobile : +94 (0) 712 415544
> Blog : http://soatechflicks.blogspot.com/
>
>
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