[rabbitmq-discuss] Messages Timeout in Queue

[GAGAN ARORA]

Alexis

Actually dropping out messages from queue is another problem I am facing and
is following it on another thread with you. In this case I am assuming there
is no dropping  out of messages from queue if there is no consumer is
listening to the queue and a message is always queued up in queue.

Thanks
Gagan

On Tue, Jul 7, 2009 at 12:03 AM, Alexis Richardson <
alexis.richardson at gmail.com> wrote:

> Gagan,
>
> On Mon, Jul 6, 2009 at 7:02 PM, GAGAN ARORA<gaganarora.itm at gmail.com>
> wrote:
> > Alexis
> >
> > a) when the User A is not logged into server 1 or server 2, any
> > messages sent to them by User B are discarded
> >>> Actually during this case no consumer would be listening to User A
> queue
> >>> and hence the messages can't be discarded and would be queued in Queue.
>
> In your document you said:
>
> "Case1: User B sending his message to UserB Exchange which will route
> message to User A queue but User A is not connected to any of servers.
> At this point of  all messages sent to Queue A should be dropped."
>
> If this is happening then the messages will be discarded and not
> queued in Queue.
>
> alexis
>
>
>
> > b) but, when User A is logged in to server 1, any messages sent by
> > User B that may be routed to User A are queued in Queue A,
> >>> No of messages increases.
> >
> > c) .... delivered when User A logs into server 2.
> >>> A large no of messages get delieverd.
> >
> > It is a constraint in my system that I have to initialize consumer when
> User
> > A connects to Server2.
> >
> > On Mon, Jul 6, 2009 at 9:28 PM, Alexis Richardson
> > <alexis.richardson at gmail.com> wrote:
> >>
> >> Gagan
> >>
> >> As I understood from your document:
> >>
> >> a) when the User A is not logged into server 1 or server 2, any
> >> messages sent to them by User B are discarded
> >> b) but, when User A is logged in to server 1, any messages sent by
> >> User B that may be routed to User A are queued in Queue A, and then
> >> ...
> >> c) .... delivered when User A logs into server 2.
> >>
> >> Provided that you can implement this efficiently (see other email)
> >> then the consumer at User A only needs to discard messages that are
> >> older than one minute, and that were not already discarded due to (a)
> >> above.  So unless the time interval between A logging into server 1,
> >> and A logging into server 2, is "quite long" then the 'timestamp'
> >> method adds very little overhead.
> >>
> >> Is that correct or have I missed something?
> >>
> >> alexis
> >>
> >>
> >>
> >>
> >>
> >>
> >> On Sat, Jul 4, 2009 at 8:28 PM, GAGAN ARORA<gaganarora.itm at gmail.com>
> >> wrote:
> >> > Hi Alexis
> >> >
> >> > My system is similar to an IM system and is using RabbitMQ for
> presence
> >> > updates and have designed it in such a way that a consumer subscribes
> to
> >> > a
> >> > queue only when it comes online.Now the issue is as stated by you
> there
> >> > will
> >> > be a large no of messages ready to be deleivered when a user comes
> >> > online.
> >> > Checking timestamp for each message will result in high cost.
> >> >
> >> > There can be a solution in which a message can be published using
> >> > immediate
> >> > flag. But it is desired by consumer to get all messages which are less
> >> > than
> >> > 1 minute old.
> >> >
> >> > Can you suggest some other solution for achieving this?
> >> >
> >> > Thanks
> >> > Gagan Arora
> >> >
> >> >
> >> >
> >> >
> >> > On Sat, Jul 4, 2009 at 3:32 PM, Alexis Richardson
> >> > <alexis.richardson at gmail.com> wrote:
> >> >>
> >> >> Gagan,
> >> >>
> >> >> On Fri, Jul 3, 2009 at 5:08 PM, GAGAN ARORA<gaganarora.itm at gmail.com
> >
> >> >> wrote:
> >> >> > Hi Alexis
> >> >> > The problem statement here is I dont want my messages in queue for
> >> >> > more
> >> >> > than
> >> >> > 1 minute.
> >> >>
> >> >> The easiest way to do this is for the client to keep consuming the
> >> >> messages from the queue.
> >> >>
> >> >> However: presumably you want messages to be ignored in the case where
> >> >> (a) there is no consumer to get the messages from the queue; and (b)
> >> >> the messages are more than one minute old.
> >> >>
> >> >> If so then: Have you considered putting a timestamp on the messages?
> >> >> That way, when a consumer starts taking messages from the queue, it
> >> >> can simply check the timestamps and throw away anything 'old'.  This
> >> >> solution works just fine when (i) you don't need real time accuracy
> >> >> ie. "about a minute" is just as good as "exactly a minute", and
> >> >> provided that (ii) there aren't too many messages to throw away.
> >> >> Judging by the document that you sent, both (i) and (ii) are true.
> >> >>
> >> >> Does this help?
> >> >>
> >> >> alexis
> >> >>
> >> >>
> >> >> > I have tried expiration property while publishing a message but
> >> >> > later came to know that it is still not implemented. Can you help
> me
> >> >> > out
> >> >> > in
> >> >> > figuring some alternate approach?
> >> >> > Thanks
> >> >> > Gagan Arora
> >> >> >
> >> >> > On Fri, Jul 3, 2009 at 8:17 PM, Alexis Richardson
> >> >> > <alexis.richardson at gmail.com> wrote:
> >> >> >>
> >> >> >> Gagan,
> >> >> >>
> >> >> >> On Fri, Jul 3, 2009 at 3:10 PM, GAGAN
> >> >> >> ARORA<gaganarora.itm at gmail.com>
> >> >> >> wrote:
> >> >> >> > Hi
> >> >> >> > Is it possible to set message time out in Java client API, so
> that
> >> >> >> > messages
> >> >> >> > drop out from queue after some interval of time if nobody
> consumes
> >> >> >> > it?.
> >> >> >>
> >> >> >> Not yet but this is a feature have been asking for quite a bit.
> >> >> >>  It's
> >> >> >> on our roadmap.
> >> >> >>
> >> >> >> There may be other ways to achieve what you want.
> >> >> >>
> >> >> >> alexis
> >> >> >>
> >> >> >>
> >> >> >>
> >> >> >> > Thanks
> >> >> >> > Gagan Arora
> >> >> >> > _______________________________________________
> >> >> >> > rabbitmq-discuss mailing list
> >> >> >> > rabbitmq-discuss at lists.rabbitmq.com
> >> >> >> >
> >> >> >> >
> http://lists.rabbitmq.com/cgi-bin/mailman/listinfo/rabbitmq-discuss
> >> >> >> >
> >> >> >> >
> >> >> >
> >> >> >
> >> >
> >> >
> >
> >
>
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