Session expiration caused by time change

2010-08-18 Thread Qing Yan
Hi, The testcase is fairly simple. We have a client which connects to ZK, registers an ephemeral node and watches on it. Now change the client machine's time - session killed.. Here is the log: *2010-08-18 04:24:57,782 INFO com.taobao.timetunnel2.cluster.service.AgentService: Host name kgb

Re: Session expiration caused by time change

2010-08-18 Thread Ted Dunning
If NTP is changing your time by more than a few milliseconds then you have other problems (big ones). On Wed, Aug 18, 2010 at 1:04 AM, Qing Yan wrote: > I guess ZK might rely on timestamp to keep sessions alive, but we have > NTP daemon running so machine time can get changed > automatically, i

Re: Session expiration caused by time change

2010-08-18 Thread Patrick Hunt
Do you expect the time to be "wrong" frequently? If ntp is running it should never get out of sync more than a small amount. As long as this is less than ~your timeout you should be fine. Patrick On 08/18/2010 01:04 AM, Qing Yan wrote: Hi, The testcase is fairly simple. We have a client

Re: Session expiration caused by time change

2010-08-18 Thread Martin Waite
Hi, I have tripped over similar problems testing Red Hat Cluster in virtualised environments. I don't know whether recent linux kernels have improved their interaction with VMWare, but in our environments clock drift caused by lost ticks can be substantial, requiring NTP to sometimes jump the clo