The liveness of a session is maintained by heart beats between ZK client and server, and this heartbeat comes as two forms: the periodic ping, or an explicit request (e..g getData). So yes, a client sends a getData request will extend the timeout of the session.
>> In other words, will a client request extend the lifetime of the session by another session timeout? I think the session will be extended to some value close to 'another session' - might not be exact value because ZK group sessions into buckets for expiration, so a session is not expired precisely as it's configured, but it should be something close. >> session timeout is configured to 10 seconds Please be aware that ZK server has minSessionTimeout and maxSessionTimeout configuration which could override what you configured at client side - the final session timeout value is some value between the two (if both values were not configured explicitly, then default multiples of tick time is used). On Thu, Oct 13, 2016 at 10:59 PM, Peng Li <peng.pen...@gmail.com> wrote: > Hi there, > > Suppose a zookeeper session timeout is configured to 10 seconds. If at time > t, a client sends a getData() request to the ensemble and succeeds, can I > assume the client's zookeeper session will be live for the next (10 - > delta) seconds according to the client's local clock? In other words, will > a client request extend the lifetime of the session by another session > timeout? > > The delta will account for clock skew between client and server. In > practice, the clock skew is bounded and very small (<<10 seconds) in a 10 > seconds interval. Absolute clock skew doesn't matter. Only the clock rate > skew matters. > > Cheers > Peng > -- Cheers Michael.