Hi John,

Message Processor Max Delivery attempt parameter is clearly documented here
[1].


Anyway in ESB 4.9.0 version we have deactivateSequence, which can be
triggered when the Message Processor is deactivated after reaching
max-delivery-attempts. In that sequence you may implement DLC pattern.

Also I understand that your requirement is valid, and you may create a
public jira to track that. We may incorporate it in to the product in a
future release.



[1] https://docs.wso2.com/display/ESB481/Message+Forwarding+Processor



Thanks & Regards,

On Wed, Sep 9, 2015 at 4:07 PM, John Hawkins <[email protected]> wrote:

> Hi Ravindra,
> I'm thinking about this a lot now....
> max.delivery.attempts is not documented anywhere nor is it in the
> MessageProcessor wizard (but it is in a few JIRA's and blog entries). Is
> this deliberate do you know - are we hiding it for some reason?
>
> Personally I would expect some kind of 'retries fail' sequence to be an
> optional thing I can set. Then I could do what I wanted with the message
> and the MessageProcessor can continue. Are you aware of any thoughts like
> this at all? If not then I think I need to create a JIRA to at least
> document this feature as-is.
>
> cheers,
> john.
>
> John Hawkins
> Director: Solutions Architecture
>
>
> On Wed, Sep 9, 2015 at 11:03 AM, Ravindra Ranwala <[email protected]>
> wrote:
>
>> Hi John,
>>
>> There is no DLC behaviour after reaching the max-retry-count at the
>> moment.
>>
>>
>> Thanks & Regards,
>>
>> On Wed, Sep 9, 2015 at 3:23 PM, John Hawkins <[email protected]> wrote:
>>
>>> Another question - is there no Dead Letter Queue behaviour then if a
>>> message fails to get sent after max_retry is done?
>>>
>>> John Hawkins
>>> Director: Solutions Architecture
>>>
>>>
>>> On Thu, Sep 3, 2015 at 4:41 PM, Ravindra Ranwala <[email protected]>
>>> wrote:
>>>
>>>> Hi John,
>>>>
>>>> The Cron expression in MP is used to create firing schedules such as
>>>> "At 8:00am every Monday through Friday" [1]. If it is set the MP will run
>>>> according to that. Otherwise MP will poll the queue with the specified
>>>> interval value continuously.
>>>>
>>>> Also the MP has a parameter called max_delivery_attempts (defaults to
>>>> 4), which defines the maximum retry attempts in case of a failure in end
>>>> point. By default if the MP could not send the message to the end point
>>>> after this number of retry count, it deactivates itself. But that message
>>>> remains in the queue. After that you have to activate the MP explicitly to
>>>> make the next schedule to be effective. Otherwise it will remain
>>>> deactivated.
>>>>
>>>> If you need to override the above behaviour, you need to enable
>>>> max-delivery-drop parameter, so that if the MP could not send the message
>>>> after this number of attempts, it merely drops the message and continues.
>>>> Here you loose the message if the endpoint is down.
>>>>
>>>>
>>>> [1]
>>>> http://www.quartz-scheduler.org/documentation/quartz-1.x/tutorials/crontrigger
>>>>
>>>>
>>>> Thanks & Regards,
>>>>
>>>> On Thu, Sep 3, 2015 at 8:05 PM, John Hawkins <[email protected]> wrote:
>>>>
>>>>> Hi All,
>>>>>
>>>>> I'm trying to figure out when does the "cron  schedule" get used that
>>>>> I can configure on the MessageProcessor?
>>>>>
>>>>> The logic that I think is happening is - if the message fails to get
>>>>> sent 'retry' number of times then it's put to the dead letter queue (or 
>>>>> DLC
>>>>> as its called in qpid) . The Message Processor then looks at the DLC based
>>>>> on when the cron job tells it to?
>>>>>
>>>>> If this logic is correct (?)  then I have a number of other questions
>>>>> please:
>>>>>
>>>>> 1) what if this cron job is not set - does the message remain on the
>>>>> DLQ?
>>>>> 2) Where is the DLQ defined  to synapse/the message processor so that
>>>>> it knows where to go?
>>>>> 3) What if the message gets removed from the DLC for some reason
>>>>> (manually or otherwise)? Do we fail quietly or log it somewhere?
>>>>> 4) What if other messages from other parts of the ESB get put to the
>>>>> DLQ ? How does the MessageProcessor know which messages are for it?
>>>>>
>>>>>
>>>>> many thanks for your help !
>>>>> john.
>>>>>
>>>>>
>>>>> John Hawkins
>>>>> Director: Solutions Architecture
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> Dev mailing list
>>>>> [email protected]
>>>>> http://wso2.org/cgi-bin/mailman/listinfo/dev
>>>>>
>>>>>
>>>>
>>>>
>>>> --
>>>> Ravindra Ranwala
>>>> Software Engineer
>>>> WSO2, Inc: http://wso2.com
>>>> <http://www.google.com/url?q=http%3A%2F%2Fwso2.com&sa=D&sntz=1&usg=AFQjCNEZvyc0uMD1HhBaEGCBxs6e9fBObg>
>>>> Mobile: +94714198770
>>>>
>>>>
>>>
>>
>>
>> --
>> Ravindra Ranwala
>> Software Engineer
>> WSO2, Inc: http://wso2.com
>> <http://www.google.com/url?q=http%3A%2F%2Fwso2.com&sa=D&sntz=1&usg=AFQjCNEZvyc0uMD1HhBaEGCBxs6e9fBObg>
>> Mobile: +94714198770
>>
>>
>


-- 
Ravindra Ranwala
Software Engineer
WSO2, Inc: http://wso2.com
<http://www.google.com/url?q=http%3A%2F%2Fwso2.com&sa=D&sntz=1&usg=AFQjCNEZvyc0uMD1HhBaEGCBxs6e9fBObg>
Mobile: +94714198770
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