Yannick, Seems a producer/consumer queue model might be more suitable for your user case, I guessed. It would be quite interesting on adapting a queue in Hedwig or based on BookKeeper. Would look into it.
-Sijie On Fri, Jan 4, 2013 at 9:01 AM, Yannick Legros <[email protected]>wrote: > "for currently, we don't support this semantic in Hedwig. I am doubting > why not subscribe first before publish. is it difficult in your case?" > > => subscribers and publishers are waiting for external events to begin > their publish/subscribe. i can't be sure of the order that my "Agents" > detects the external event. So in some cases the publishers starts before > the subscribers and i can loose few message :-(. > > > "if to support your semantic, all the messages had to be kept until a > subscriber arrived. if there is no subscriber, how to deal with those > published messages? kept them forever?" > > => I know that hedwig is a pub/sub framwork and it is not a treatment > queue, but keep them during a parametrized time would be great > > thanks, > > Yannick. > > > 2012/12/29 Sijie Guo <[email protected]> > >> thanks, yannick. I got your idea. >> >> for currently, we don't support this semantic in Hedwig. I am doubting >> why not subscribe first before publish. is it difficult in your case? >> >> if to support your semantic, all the messages had to be kept until a >> subscriber arrived. if there is no subscriber, how to deal with those >> published messages? kept them forever? >> >> -Sijie >> >> >> On Sat, Dec 29, 2012 at 3:58 AM, Yannick Legros < >> [email protected]> wrote: >> >>> thanks for your answer sijie. >>> >>> what i need is not exactly >>> "subscribers be aware of messages publish before they subscribe" >>> but >>> "be sure that my message be consume by almost one subscriber" >>> >>> so if a publisher publish message on topics with no subscribers the >>> first subscriber who will read the topics will get all published messages >>> before his subscription. >>> >>> hope i was clear. >>> >>> Thanks, yannick. >>> >>> 2012/12/28 Sijie Guo <[email protected]> >>> >>>> > does this is the default behaviour of hedwig? >>>> >>>> A subscriber would receive all the messages published after its first >>>> time subscribe until it unsubscribe. >>>> >>>> so go back to your example: >>>> >>>> 1) if the subscriber subscribe T first time, it would only receive M2. >>>> 2) if the subscriber already subscribe before M1. so the subscribe >>>> between M1 and M2 is an attach subscribe, so it would receive M1 and M2 >>>> eventually (if it doesn't receive M1 at its first time subscribe) >>>> >>>> > can we configure something (in subscription option for exemple) for >>>> subscribers be aware of messages publish before they subscribe and not >>>> consumed yet. >>>> >>>> Currently Hedwig doesn't support it. But I am just curious why a >>>> subscriber need to be aware of messages published before they subscribed? >>>> Is there any special case you are considering? >>>> >>>> -Sijie >>>> >>>> >>>> On Fri, Dec 28, 2012 at 3:23 AM, Yannick Legros < >>>> [email protected]> wrote: >>>> >>>>> Hello, >>>>> >>>>> I have just another question. >>>>> >>>>> in this case : >>>>> >>>>> publisher post a message M1 on topics T >>>>> subscriber subscribe to T >>>>> publisher post a message M2 on topics T >>>>> >>>>> when subscriber starts delivery he will get M2 but not M1 because he >>>>> has subscribed after M1 was publish. >>>>> >>>>> does this is the default behaviour of hedwig? >>>>> can we configure something (in subscription option for exemple) for >>>>> subscribers be aware of messages publish before they subscribe and not >>>>> consumed yet. >>>>> >>>>> thanks a lot. >>>>> >>>> >>>> >>> >> >
