[Pulp-list] Messaging Questions

[Bryan Kearney]

On 07/12/2010 09:08 AM, Todd B Sanders wrote:
> On 07/08/2010 05:06 PM, Jason Dobies wrote:
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>>> Open questions which I see:
>>>
>>> 1) Does pulp require durable queues? Do I want to ensure that a packge
>>> is updated the next time it wakes up? If so, we need to handle queue
>>> purging. Perhaps this is tied to consumer deletion.
>>>
>>> 2) Can the same message (install package) be sent P2P Sync, Fire and
>>> Forget, and broadcast. I think the answer to this should be yes. If so,
>>> in broadcast, is there a notion of the success/failure?
>> 1 and 2 are kinda related, so I'll answer both here.
>>
>> This is a really interesting question. If a user says to install a
>> package and the agent isn't currently available, will the user still
>> want it installed in the future when it is available?
>>
>> I think if we add a time factor to the request (i.e. "only do this if
>> you get the message before 8am") I'm more inclined to go with only using
>> durable queues for package installs. It feels like too critical of an
>> operation to leave open to a non-guaranteed paradigm.
>>
>>> 3) Will Jason Dobies choose to argue against himself who is arguing
>>> against himself? if so, is he correct no matter what the outcome?
>> I'm glad you came to the realization that I'm always correct. :)
>>
>>> 4) Is there a hearbeat requirement? I have not heard of any.
>> It's starting to sound like there is. If we go durable queues, this is
>> gonna be the way we clean up queues for dead agents. Even if there
>> isn't, I think it's a trivial enough addition to give us minimalistic
>> availability information. Good bang for the buck there.
>
> We sort of had this with Satellite and rhn-check. Out of the box,
> managed systems check in with the server every 4-hours. We then
> high-light inactive systems. Seems to me that a heartbeat is a good way
> to achieve similar information. So, IMO, it is a requirement.
>
> -Todd

Do you envision the heartbeat over rest, or AMQP?

-- bk