Hi Edward, Thank You very much for the response.
Yes I wanted to know about sequencial node part. so the usecase is when two clients try to create same nodes with same name zk change the naming ? If my system is well defined and no random node creation I do not need this feature ? If I have random node creation I always have to get the childnodes and then get the nodes based on naming ? or can I just stick to the name I gave when I tried to save the node ? In your example I think clients tried to create the nodes with the name /leader/serv but zk created something else. ex: leader/serv_000000001 In this case can I just get the node with /leader/serv or should I get with /leader/serv_000000001 Anyways for my application I do not need this because I do not have a scenario where naming is nondeterministic between zk clients. Regards Lahiru On Fri, Jun 20, 2014 at 9:42 AM, Edward Ribeiro <[email protected]> wrote: > Hi Lahiru, > > You mean EPHEMERAL and EPHEMERAL_SEQUENTIAL, right? > > A znode is created by a client logged on a session. Both EPHEMERAL and > EPHEMERAL_SEQUENTIAL znodes are deleted once the session -- where the znode > was created -- expires (that is, the user disconnects). The difference > between the two types of ephemeral node is that EPHEMERAL_SEQUENTIAL allows > you to create an atomic and sequentially increasing number suffixes. > > For example, if three clients are trying to create child > ephemeral_sequential znodes of a '/leader' parent znode at the same time > they will be generated as follows (for example): > > /leader/serv_000000001 > /leader/serv_000000002 > /leader/serv_000000003 > > the number suffix was automatically appended by ZK such that no two clients > will generate the same znode (serv_00000001, for example). If the client > which created znode 'serv_00000002' disconnects then ZK automatically > deletes that znode. > > Got it? > > Edward > > > > > > On Thu, Jun 19, 2014 at 2:53 PM, Lahiru Gunathilake <[email protected]> > wrote: > > > When creating a node we have to parse the constants and there are four. > > PERSISTENT, PERSISTENT_SEQUENTIAL, EPHEMERAL, EPHEMERAL_SEQUENTIAL > > > > I do not really get the description of two constants EPEHMERAL_SEQUENCIAL > > and EPHEMERAL_SEQUENTIAL. In API docs it says like below. > > > > The znode will be deleted upon the client's disconnect, and its name will > > be appended with a monotonically increasing number. > > > > Can someone please describe me what this is about. > > > > Regards > > Lahiru > > > > -- > > System Analyst Programmer > > PTI Lab > > Indiana University > > > -- System Analyst Programmer PTI Lab Indiana University
