On 4 September 2014 19:13, xiaodan.wang <[email protected]> wrote:
> Looks like I replied before seeing your followup :) > > > > To expand a little further... The behaviour I'm thinking about for 0-9-1 > > would be that on a synchronous session, every time you call receive() the > > client opens up the credit window enough for you to receive a message if > > there isn't currently credit enough to get the message. At the point a > > commit occurs (on a transacted session), or an acknowledge (on a client > > ack > > session), the window is reduced again such that no new messages will be > > prefetched until a receive is called... > > And also if the window could be reduced when "receive" times out, mainly to > prevent a message that arrives after we've started working on the > previously > dequeued set of message. > > OK - good point - I'll add that to the requirements :-) > > > The other (potentially simpler for me, but hackier) possibility would be > > to > > provide some way of allowing you to manually flex the prefetch size on an > > individual session... this would probably require casting into a qpid > > specific class for you so you could directly manipulate the session > > object. > > Would the manual re-sizing be done dynamically or only at session creation > time? For us, over-sizing (setting prefetch of 10 when there are only 8 > messages at the moment) could lead to the starvation of late arrival > messages mentioned above. > > At the moment I'm thinking the 0-9 behaviour described above is the right way to go, because, basically it is the sane behaviour anyone would want from a synchronous session. The only issue is where you have mutliple consumers on a single session in which case you might ask to receive() on one consumer, but the prefetched message arrives on a different consumer... In your case, in the synchronous session do you just have the one onsumer on the session? -- Rob > Cheers! Dan > > > > -- > View this message in context: > http://qpid.2158936.n2.nabble.com/Synchronous-consumer-can-only-dequeue-1-message-in-AMQP-0-91-tp7613017p7613072.html > Sent from the Apache Qpid users mailing list archive at Nabble.com. > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [email protected] > For additional commands, e-mail: [email protected] > >
