I like the idea of doing this in the broker if it's feasible. -- Devin G. Bost
On Mon, Apr 19, 2021, 7:42 AM Enrico Olivelli <eolive...@gmail.com> wrote: > Penghui > > Il giorno lun 19 apr 2021 alle ore 15:11 PengHui Li > <codelipeng...@gmail.com> ha scritto: > > > > Hi enrico, > > > > The delayed message feature is to support messages that can have any > delay in a single partition. > > So, if the broker dispatches the messages based on the available time of > the message, this will break the FIFO order. > > > > So, if I understand correctly, "the behaviour of delayed messages even > > for Exclusive subscriptions, still preserving a strict FIFO order” means > messages of a partition has same delay time? > > If so, I think we can achieve this at the client-side(Just check the > head message is available or not) > > At a high level I would like that the feature works well for the user, > independently from how it is implemented, > infact now it is difficult to explain to users that they may receive > unexpected messages if they are using some "wrong" subscription type. > > Regarding a possible implementation I wonder if we can implement it at > the broker side in order to save resources: > - do not transfer the message if not needed > - do not need to bounce back the message (negativeAck ?) in case that > the message is not ready to be consumed > > Holding the message on the client until the message is deliverable is > a bit complicated to implement and if we go this way we will have to > implement > it on every client (Java....) > > > Enrico > > > > > > Thanks, > > Penghui > > On Apr 19, 2021, 8:00 PM +0800, Enrico Olivelli <eolive...@gmail.com>, > wrote: > > > Hi, > > > I came across this great feature, Delayed Messages > > > https://github.com/apache/pulsar/wiki/PIP-26:-Delayed-Message-Delivery > > > > > > And I see that this feature does not work with Exclusive and Failover > > > subscriptions. > > > The reason explained in the PIP is that this is because we want to > > > guarantee FIFO order. > > > > > > I wonder if we could implement the behaviour of delayed messages even > > > for Exclusive subscriptions, still preserving a strict FIFO order. > > > > > > Enrico >
