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Posted to user@mesos.apache.org by James Vanns <jv...@gmail.com> on 2015/11/18 13:09:49 UTC
statusUpdate() duplicate messages?
Hello list.
We have an experimental framework (C++ API) based on Mesos 0.24 and we're
seeing duplicate task status messages -- eg. 2 'FINISHED' messages for a
single task. This may well be normal behaviour but I wasn't prepared for
it. Could someone point me in the direction of a decent description on
status updates/messages somewhere in the Mesos documentation? Or explain
the following;
a) Is this normal (it's not just the FINISHED state)?
b) What might cause this behaviour (it's intermittent)?
c) I do not explicitly acknowledge receipt of these messages - should I!?
d) Should I treat these status update messages as reliable and robust!?
e) Where can I learn more about this kind of internal detail?
Cheers,
Jim
--
Senior Code Pig
Industrial Light & Magic
Re: statusUpdate() duplicate messages?
Posted by Vinod Kone <vi...@gmail.com>.
Look for UPDATE and ACKNOWLEDGE sections in
https://github.com/apache/mesos/blob/master/docs/scheduler-http-api.md for
semantics. Note that this doc for schedulers using the new HTTP API, but
the semantics around updates are the same.
On Wed, Nov 18, 2015 at 4:41 AM, James Vanns <jv...@gmail.com> wrote:
> Thanks very much for the prompt response, Tom. I shall go and read up on
> reconciliation (I'd expected there to be something like this to read). And
> to my knowledge, no I don't explicitly disable the implicit status
> acknowledgement ;)
>
> Cheers,
>
> Jim
>
>
> On 18 November 2015 at 12:24, Tom Arnfeld <to...@duedil.com> wrote:
>
>> When you construct the scheduler, are you disabling implicit
>> acknowledgements?
>>
>> https://github.com/apache/mesos/blob/master/include/mesos/scheduler.hpp#L373
>>
>> I’d suggest having a read over this document, it explains some of this ->
>> http://mesos.apache.org/documentation/latest/reconciliation/
>>
>> a) Mesos may re-send messages if you don’t acknowledge them, and task
>> status messages are guaranteed *at least once*
>> c) If you disable implicit status acknowledgement, yep
>> d) You should, they are guaranteed to be delivered *at some point* *at
>> least once* by the slave / master. To keep your framework in sync with
>> the cluster it is recommended to reconcile tasks often (as explained in the
>> document above)
>> e) http://mesos.apache.org/documentation/latest/reconciliation/
>>
>> Hope that helps, and I think that’s all correct! The docs will be able to
>> clarify better :-)
>>
>> On 18 Nov 2015, at 12:09, James Vanns <jv...@gmail.com> wrote:
>>
>> Hello list.
>>
>> We have an experimental framework (C++ API) based on Mesos 0.24 and we're
>> seeing duplicate task status messages -- eg. 2 'FINISHED' messages for a
>> single task. This may well be normal behaviour but I wasn't prepared for
>> it. Could someone point me in the direction of a decent description on
>> status updates/messages somewhere in the Mesos documentation? Or explain
>> the following;
>>
>> a) Is this normal (it's not just the FINISHED state)?
>> b) What might cause this behaviour (it's intermittent)?
>> c) I do not explicitly acknowledge receipt of these messages - should I!?
>> d) Should I treat these status update messages as reliable and robust!?
>> e) Where can I learn more about this kind of internal detail?
>>
>> Cheers,
>>
>> Jim
>>
>> --
>> Senior Code Pig
>> Industrial Light & Magic
>>
>>
>>
>
>
> --
> --
> Senior Code Pig
> Industrial Light & Magic
>
Re: statusUpdate() duplicate messages?
Posted by James Vanns <jv...@gmail.com>.
Thanks very much for the prompt response, Tom. I shall go and read up on
reconciliation (I'd expected there to be something like this to read). And
to my knowledge, no I don't explicitly disable the implicit status
acknowledgement ;)
Cheers,
Jim
On 18 November 2015 at 12:24, Tom Arnfeld <to...@duedil.com> wrote:
> When you construct the scheduler, are you disabling implicit
> acknowledgements?
>
> https://github.com/apache/mesos/blob/master/include/mesos/scheduler.hpp#L373
>
> I’d suggest having a read over this document, it explains some of this ->
> http://mesos.apache.org/documentation/latest/reconciliation/
>
> a) Mesos may re-send messages if you don’t acknowledge them, and task
> status messages are guaranteed *at least once*
> c) If you disable implicit status acknowledgement, yep
> d) You should, they are guaranteed to be delivered *at some point* *at
> least once* by the slave / master. To keep your framework in sync with
> the cluster it is recommended to reconcile tasks often (as explained in the
> document above)
> e) http://mesos.apache.org/documentation/latest/reconciliation/
>
> Hope that helps, and I think that’s all correct! The docs will be able to
> clarify better :-)
>
> On 18 Nov 2015, at 12:09, James Vanns <jv...@gmail.com> wrote:
>
> Hello list.
>
> We have an experimental framework (C++ API) based on Mesos 0.24 and we're
> seeing duplicate task status messages -- eg. 2 'FINISHED' messages for a
> single task. This may well be normal behaviour but I wasn't prepared for
> it. Could someone point me in the direction of a decent description on
> status updates/messages somewhere in the Mesos documentation? Or explain
> the following;
>
> a) Is this normal (it's not just the FINISHED state)?
> b) What might cause this behaviour (it's intermittent)?
> c) I do not explicitly acknowledge receipt of these messages - should I!?
> d) Should I treat these status update messages as reliable and robust!?
> e) Where can I learn more about this kind of internal detail?
>
> Cheers,
>
> Jim
>
> --
> Senior Code Pig
> Industrial Light & Magic
>
>
>
--
--
Senior Code Pig
Industrial Light & Magic
Re: statusUpdate() duplicate messages?
Posted by Tom Arnfeld <to...@duedil.com>.
When you construct the scheduler, are you disabling implicit acknowledgements?
https://github.com/apache/mesos/blob/master/include/mesos/scheduler.hpp#L373 <https://github.com/apache/mesos/blob/master/include/mesos/scheduler.hpp#L373>
I’d suggest having a read over this document, it explains some of this -> http://mesos.apache.org/documentation/latest/reconciliation/ <http://mesos.apache.org/documentation/latest/reconciliation/>
a) Mesos may re-send messages if you don’t acknowledge them, and task status messages are guaranteed at least once
c) If you disable implicit status acknowledgement, yep
d) You should, they are guaranteed to be delivered at some point at least once by the slave / master. To keep your framework in sync with the cluster it is recommended to reconcile tasks often (as explained in the document above)
e) http://mesos.apache.org/documentation/latest/reconciliation/ <http://mesos.apache.org/documentation/latest/reconciliation/>
Hope that helps, and I think that’s all correct! The docs will be able to clarify better :-)
> On 18 Nov 2015, at 12:09, James Vanns <jv...@gmail.com> wrote:
>
> Hello list.
>
> We have an experimental framework (C++ API) based on Mesos 0.24 and we're seeing duplicate task status messages -- eg. 2 'FINISHED' messages for a single task. This may well be normal behaviour but I wasn't prepared for it. Could someone point me in the direction of a decent description on status updates/messages somewhere in the Mesos documentation? Or explain the following;
>
> a) Is this normal (it's not just the FINISHED state)?
> b) What might cause this behaviour (it's intermittent)?
> c) I do not explicitly acknowledge receipt of these messages - should I!?
> d) Should I treat these status update messages as reliable and robust!?
> e) Where can I learn more about this kind of internal detail?
>
> Cheers,
>
> Jim
>
> --
> Senior Code Pig
> Industrial Light & Magic