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From Ted Dunning <ted.dunn...@gmail.com>
Subject Re: ntp adjust to zookeeper
Date Thu, 23 Jun 2011 16:28:35 GMT
That is a really fast timeout.  It can be kind of tricky to actually meet
that requirement on the client side and even if NTP doesn't jump by that
much, if the client is missing for a big chunk of that time at the same time
a much smaller NTP jump happens, you could be in for trouble.

>From the documentation:


   -

   settimeofday(2) to step (set) the time. This method is used if the time
   if off by more than 128ms.

This looks like you could easily see steps > 2s

2011/6/22 Donna Li <donna.li@utstar.com>

>
> my server configuration is as following:
> tickTime=1000
> initLimit=5
> syncLimit=2
>
> client api:
> zookeeper_init(,,recv_timeout=2000,)
>
> So client will session expire by 2s if server can not receive the
> heartbeat. Does the ntp max jump time = 2s?
>
>
> -----邮件原件-----
> 发件人: Ted Dunning [mailto:ted.dunning@gmail.com]
> 发送时间: 2011年6月23日 10:12
> 收件人: user@zookeeper.apache.org
> 主题: Re: ntp adjust to zookeeper
>
> Large time jumps can cause problems because your sessions may expire
> surprisingly.
>
> It is best to keep your servers within a tight tolerance.  Time jumps may
> occur more seriously if you are using an over-subscribed VM (think small
> EC2
> instances).  That can seriously confuse NTP and cause real problems.
>
> On Wed, Jun 22, 2011 at 6:34 PM, Donna Li <donna.li@utstar.com> wrote:
>
> > All:
> >
> >        Could zookeeper cluster servers work normal after ntp adjust?
> >
> >
> >
> >
> >
> > Best Regards
> >
> > Donna li
> >
> >
>

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