On 09/18/2014 05:42 PM, Steve Lewis wrote: > On September 18, 2014 7:45 AM, Flavio Percoco wrote: > >> On 09/18/2014 04:09 PM, Gordon Sim wrote: >> >>> However, as far as consuming messages is concerned, it can >>> guarantee once-and-only-once and/or at-least-once delivery depending on >>> the message pattern used to consume messages. Using pop or claims >>> guarantees the former whereas streaming messages out of Zaqar guarantees >>> the later. >>> >>> From what I can see, pop provides unreliable delivery (i.e. its similar >>> to no-ack). If the delete call using pop fails while sending back the >>> response, the messages are removed but didn't get to the client. >> >> Correct, pop works like no-ack. If you want to have pop+ack, it is >> possible to claim just 1 message and then delete it. > > Having some experience using SQS I would expect that there would be a mode > something like what SQS provides where a message gets picked up by one > consumer (let's say by short-polling) and is hidden for a timeout duration > from > other consumers, so that the consumer has time to ack. Is that how you are > using the term 'claim' in this case?
Correct, that's the name of the feature in Zaqar. You can find a bit of extra information here[0]. Hope this helps. [0] https://wiki.openstack.org/wiki/Zaqar/specs/api/v1.1#Claims Cheers, Flavio -- @flaper87 Flavio Percoco _______________________________________________ OpenStack-dev mailing list OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
