Hi Gustavo, Usually the paradigm I like to suggest is to have something like
/A/init Every client watches for the existence of this node and this node is only created after /A has been initialized with the creation of /A/C or other stuff. Would that work for you? Thanks mahadev On 8/23/10 7:34 AM, "Gustavo Niemeyer" <gust...@niemeyer.net> wrote: > Greetings, > > We (a development team at Canonical) are stumbling into a situation > here which I'd be curious to understand what is the general practice, > since I'm sure this is somewhat of a common issue. > > It's quite easy to describe it: say there's a parent node A somewhere > in the tree. That node was created dynamically over the course of > running the system, because it's associated with some resource which > has its own life-span. Now, under this node we put some control nodes > for different reasons (say, A/B), and we also want to track some > information which is related to a sequence of nodes (say, A/C/D-0, > A/C/D-1, etc). > > So, we end up with something like this: > > A/B > A/C/D-0 > A/C/D-1 > > The question here is about best-practices for taking care of nodes > like A/C. It'd be fantastic to be able to create A's structure > together with A itself, otherwise we risk getting in a situation where > a client can see the node A before its "initialization" has been > finished (A/C doesn't exist yet). In fact, A/C may never exist, since > it is possible for a client to die between the creation of A and C. > > Anyway, I'm sure you all understand the problem. The question here > is: this is pretty common, and quite boring to deal with properly on > every single client. Is there any feature in the roadmap to deal with > this, and any common practice besides the obvious "check for > half-initialization and wait for A/C to be created or deal with > timeouts and whatnot" on every client? > > I'm about to start writing another layer on top of Zookeeper's API, so > it'd be great to have some additional insight into this issue. > > -- > Gustavo Niemeyer > http://niemeyer.net > http://niemeyer.net/blog > http://niemeyer.net/twitter >
