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 <ravin...@wso2.com> 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 <jo...@wso2.com> 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 >> Dev@wso2.org >> 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 > >
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