[rm-wg] Fwd: Lifecycle Extensiond
David Snelling
David.Snelling at UK.Fujitsu.com
Thu Apr 12 07:49:49 CDT 2007
Begin forwarded message:
> From: David Snelling <David.Snelling at uk.fujitsu.com>
> Date: 14 March 2007 22:48:40 GMT
> To: "Strong, Paul" <pstrong at ebay.com>
> Cc: David Snelling <David.Snelling at UK.Fujitsu.com>
> Subject: Re: Lifecycle Extensiond
>
> Paul,
>
> On 6 Mar 2007, at 18:34, Strong, Paul wrote:
>
>> Hi Dave,
>>
>> So I've looked at these and have been thinking...
>>
>> I like the mind map idea a lot as a way of viewing our problem
>> space in
>> a qualitative sense, although I am typically somewhat averse to the
>> notion of transition states such as Commissioning and so forth.
>> Where
>> do you stop? :o)
>
> I'm not that sure either. WRT management, the next bit of
> information a manager might need is "what is supposed to happen
> next to this thing?" That may be what we were after.
>
>> I would view them as sub-states of the existing
>> states.
>
> For the *-ing states that are intended as optional sub-states.
>
>> We define the test that defines what it means to be in a given
>> state. Those tests can be very simple. Below are some ideas but
>> they
>> need discussion/-fleshing out and I'm pretty sure that the Configured
>> test is not right yet. ;o) But you get the idea.
>>
>> Active State - Test = Fulfils its function - i.e. is responding to
>> transactions or is still doing its calculation. Sub states include
>> running, stopping, failing (before it has ceased to serve its
>> purpose),
>> canceling etc.
>
> Looks OK.
>
>> Configured - Test = Has a full set of configuration and data files
>> required to run, even if those may cause it to fail. The point is
>> that
>> the component can be started. Sub-states include startable,
>> starting,
>> failing (the bit after it no longer satisfies the serving purpose
>> test),
>> stopping, canceling, decommissioning.
>
> I still like Commissioned and separating out the "bit after it no
> longer satisfies the serving purpose test" states.
>
>> Discovered - Test = Has been registered by the system, i.e. has a
>> unique
>> identifier and associated records of its properties and
>> attributes. Sub
>> states include deleting, configuring.
>
> The test i right. For me, it has a WS-Addressing EPR and will
> respond to WSRF-Lifetime actions. One it is WSRF-LT:Destroyed, it
> ain't there non more. My adjective, "Extant", was recommended by my
> kids, based on the first question the family always asks in the
> "I'm thinking of an animal." game. - "Is it extinct or extant?"
>
>> We can also perhaps sub-class (so to speak) the transitions to
>> include,
>> for example, Stop(Failed), Stop(Succeeded) and so forth if that is
>> possible, otherwise we can perhaps add transitions. It's all
>> about how
>> we define the states and the transitions. I might posit the
>> sub-transition notion to Grady if I can't find a suitable extant
>> mechanism.
>
> We did a lot of brainstorming with UML 2.0 guards etc to try and
> capture all this, but the thinking process get hard to verify. Sub-
> typing the transitions, if we keep them in the data structure,
> might work. the problem we get in the end, is this all has to be
> rendered in XML comprehensible to fairly brain dead tooling.
>
>> I think the discussion is really useful. And as you know I am a
>> massive
>> fan of simplicity at the abstract level that can then be built
>> upon, so
>> that complex entities and behaviors can be represented yet easily
>> understood.
>
> I like this flavor ice cream too, but I like a sauce on it that
> says, how far can we push the abstraction before it breaks. Then
> back off a little and try to simplify again. I think this is a
> healthy tension. See you at OGSA.
>
>
>
> --
>
> Take care:
>
> Dr. David Snelling < David . Snelling . UK . Fujitsu . com >
> Fujitsu Laboratories of Europe Limited
> Hayes Park Central
> Hayes End Road
> Hayes, Middlesex UB4 8FE
> Reg. No. 4153469
>
> +44-208-606-4649 (Office)
> +44-7768-807526 (Mobile)
>
>
>
--
Take care:
Dr. David Snelling < David . Snelling . UK . Fujitsu . com >
Fujitsu Laboratories of Europe Limited
Hayes Park Central
Hayes End Road
Hayes, Middlesex UB4 8FE
Reg. No. 4153469
+44-208-606-4649 (Office)
+44-7768-807526 (Mobile)
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