Re: zookeeper ephemeral node expired time not accurate

[朱晨杰 <zc...@gmail.com>]

Hi, Ted:
   In the Zookeeper config file, I set tickTime=1000, does this parameter
decide the frequency of heartbeat? I have change this parameter to
different value, but the expiration time is still not accurate

2012/1/1 Ted Dunning <te...@gmail.com>

> The client sends heart-beats to the server.  When the time since the last
> heartbeat is long enough, the server deems the client to have failed or
> been partitioned away from the cluster.
>
> If you have heartbeats every 5s and an session expiration time of 10s, then
> if you kill the connection just before the next heartbeat, the server would
> be justified in expiring the session 5+epsilon seconds after the connection
> is lost.
>
> You can configure heartbeats to occur more often if you want.
>
> On Sat, Dec 31, 2011 at 4:32 AM, 朱晨杰 <zc...@gmail.com> wrote:
>
> > Hi, everyone:
> >    I have done some tests and find that the expired time of ephemeral
> node
> > is not accurate. I set my connection's timeout to be "10s" when
> connecting
> > to zookeeper. Then I create an ephemeral node. I start another
> application
> > set watch on this ephemeral node. When I close the first connection, the
> > watch will be triggered and I got the message. I compare the time when I
> > close the connection and the time when I got the message reporting the
> > disappearance of the ephemeral node, I find it's always not 10 seconds.
> > Most of the situation, it will be less than 10 seconds, about 8, or 7,
> even
> > 6 seconds. Can anyone tell me why this happen? I want to figure out how
> > does zookeeper decide a connection expire. Thanks
> >
> > --
> > Zhu Chenjie
> > Zhejiang University, China
> >
>



-- 
Zhu Chenjie
Zhejiang University, China

Re: zookeeper ephemeral node expired time not accurate

[Ted Dunning <te...@gmail.com>]

See
http://zookeeper.apache.org/doc/r3.2.2/zookeeperAdmin.html#sc_configurationfor
more information.

The minimum session expiration time is a small multiple of this number so
it isn't surprising that you still see inaccuracy.

Have you tried setting it to a very small value like 200?

2011/12/31 朱晨杰 <zc...@gmail.com>

> Hi, Ted:
>   In the Zookeeper config file, I set tickTime=1000, does this parameter
> decide the frequency of heartbeat? I have change this parameter to
> different value, but the expiration time is still not accurate
>
> 2012/1/1 Ted Dunning <te...@gmail.com>
>
> > The client sends heart-beats to the server.  When the time since the last
> > heartbeat is long enough, the server deems the client to have failed or
> > been partitioned away from the cluster.
> >
> > If you have heartbeats every 5s and an session expiration time of 10s,
> then
> > if you kill the connection just before the next heartbeat, the server
> would
> > be justified in expiring the session 5+epsilon seconds after the
> connection
> > is lost.
> >
> > You can configure heartbeats to occur more often if you want.
> >
> > On Sat, Dec 31, 2011 at 4:32 AM, 朱晨杰 <zc...@gmail.com> wrote:
> >
> > > Hi, everyone:
> > >    I have done some tests and find that the expired time of ephemeral
> > node
> > > is not accurate. I set my connection's timeout to be "10s" when
> > connecting
> > > to zookeeper. Then I create an ephemeral node. I start another
> > application
> > > set watch on this ephemeral node. When I close the first connection,
> the
> > > watch will be triggered and I got the message. I compare the time when
> I
> > > close the connection and the time when I got the message reporting the
> > > disappearance of the ephemeral node, I find it's always not 10 seconds.
> > > Most of the situation, it will be less than 10 seconds, about 8, or 7,
> > even
> > > 6 seconds. Can anyone tell me why this happen? I want to figure out how
> > > does zookeeper decide a connection expire. Thanks
> > >
> > > --
> > > Zhu Chenjie
> > > Zhejiang University, China
> > >
> >
>
>
>
> --
> Zhu Chenjie
> Zhejiang University, China
>