i can answer the last question about sequence ids. the ids are independent between regions. region A may publish a, b, c and region B may publish x, y, z. region A's sequence may be (1,a), (2,b), (3,c), (4, x), (5,y), (6,z). while region B's sequence may be (1,x), (2,a), (3, b), (4,c), (5, y), (6,z).
i'm not sure what is supposed to happen if you try to subscribe to a topic and a region is down. utkarsh would be a better person to comment on that. ben On Fri, Dec 16, 2011 at 3:03 AM, Ivan Kelly <[email protected]> wrote: > I've been reviewing Sijie's patch for BOOKKEEPER-140 and I can't figure out > how cross region publication is supposed to work. Perhaps someone on the list > can help out. My problem is that I can't see how the guaranteed delivery > works. > > The delivery guarantee, as I understand it, will guarantee that you will > receive all messages, in order, which have been published to a topic, from > the point at which you subscribe to the topic. > > I can see how this works for a single region. However, for more than one > region, what should happen if a region A is down when the subscription is > created at region B. If the subscription is eventually made to A, should it > get all messages from all regions published from the point it subscribed at > B, or should it only get them from region A from the point at which the > subscription reached region A. > > Really I guess the question boils down to, how do the message sequence ids > between regions interact? Is there any total order between them, or are they > completely independent, or a mix of the two? > > -Ivan
