Yeah - I guess to explain a little more... we have a very large number of clients out in the wild that in essence going to each pool of clients would be a huge hassle and pain. So - yes we could update our client and provide a watcher switch but it would be very cumbersome to get to and update each of the clients. We could also change the ZK structure - but again we would have to change all of the clients in the wild - a step we are trying to avoid.
In short we were looking for just a quick workaround or hack from the server ensemble perspective even though it may not be a supported or recommended function - this would be just a one time thing for us. Thanks Ben On Sep 2, 2011, at 12:22 AM, Ted Dunning wrote: > I would recommend not spending a whole lot of time figuring out how to make > Zookeeper lie to the clients. It is hard enough to make distributed > software that tells the truth. > > Why don't you just make the ZK structure match what you are trying to do? > For instance, have a znode containing the key and a separate znode that is > just for watching. Then the server has the option of updating both znodes > or just the key depending on what behavior you want to get. > > This is simple and straightforward and makes it very clear what you mean to > do. Why hack the server for such a thing? > > On Fri, Sep 2, 2011 at 1:37 AM, Mahadev Konar <[email protected]>wrote: > >> Ben, >> I dont think I fully understand the use case. Is it possible that you >> can register a different callback for that key? >> >> Something like: >> >> zk.exists(String path, Watcher watcher) >> >> where you can register a different watcher for this path? >> >> Would this work? >> >> mahadev >> >> >> On Thu, Sep 1, 2011 at 5:58 PM, Ben Hall <[email protected]> wrote: >>> Hi, >>> >>> We have an interesting problem use case that we wanted to ping the group >> about. >>> >>> We have a Key on all of our Ensemble servers. All of our clients are >> also subscribed to this key. We want to remove the key from the ensemble >> servers without this action getting propagated down to the clients. Or if >> it does get propagated down - at a minimum we do not want to watch callback >> function to be called. >>> >>> Is there a way to in essence sever the watches from the server >> perspective without the client knowing? >>> >>> We are investing looking into the hidden keys on the zookeeper servers >> that hold the list of watches and possibly editing that key. has anyone >> done that before? Do we know what happens when that key is edited manually? >>> >>> Any other suggestions or possibilities available to us? >>> >>> Thanks >>> Ben >>
