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Zookeeper, mail # user - leader election, scheduled tasks, losing leadership


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Eric Pederson 2012-12-09, 04:17
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Jordan Zimmerman 2012-12-09, 04:25
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Eric Pederson 2012-12-09, 04:49
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Jordan Zimmerman 2012-12-09, 04:52
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Eric Pederson 2012-12-09, 04:54
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Jordan Zimmerman 2012-12-09, 04:57
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Eric Pederson 2012-12-09, 04:56
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Jordan Zimmerman 2012-12-09, 05:00
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Henry Robinson 2012-12-09, 05:02
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Jordan Zimmerman 2012-12-09, 05:04
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Henry Robinson 2012-12-09, 05:12
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Jordan Zimmerman 2012-12-09, 05:18
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Henry Robinson 2012-12-09, 05:30
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Jordan Zimmerman 2012-12-09, 05:41
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Eric Pederson 2012-12-09, 21:42
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Eric Pederson 2012-12-09, 22:10
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Vitalii Tymchyshyn 2012-12-10, 06:49
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Eric Pederson 2012-12-10, 11:52
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Vitalii Tymchyshyn 2012-12-11, 20:09
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Eric Pederson 2012-12-12, 00:54
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Re: leader election, scheduled tasks, losing leadership
Henry Robinson 2012-12-09, 04:59
Eric -

Might be helpful if you post the code that you had as one of your slides so
that we can see exactly what you're doing.

Henry

On 8 December 2012 20:56, Eric Pederson <[EMAIL PROTECTED]> wrote:

> If I recall correctly it was Henry Robinson that gave me the advice to have
> a "task in progress" check.
>
>
> -- Eric
>
>
>
> On Sat, Dec 8, 2012 at 11:54 PM, Eric Pederson <[EMAIL PROTECTED]> wrote:
>
> > I am using Curator LeaderLatch :)
> >
> >
> > -- Eric
> >
> >
> >
> >
> > On Sat, Dec 8, 2012 at 11:52 PM, Jordan Zimmerman <
> > [EMAIL PROTECTED]> wrote:
> >
> >> You might check your leader implementation. Writing a correct leader
> >> recipe is actually quite challenging due to edge cases. Have a look at
> >> Curator (disclosure: I wrote it) for an example.
> >>
> >> -JZ
> >>
> >> On Dec 8, 2012, at 8:49 PM, Eric Pederson <[EMAIL PROTECTED]> wrote:
> >>
> >> > Actually I had the same thought and didn't consider having to do this
> >> until
> >> > I talked about my project at a Zookeeper User Group a month or so ago
> >> and I
> >> > was given this advice.
> >> >
> >> > I know that I do see leadership being lost/transferred when one of the
> >> ZK
> >> > servers is restarted (not the whole ensemble).   And it seems like
> I've
> >> > seen it happen even when the ensemble stays totally stable (though I
> am
> >> not
> >> > 100% sure as it's been a while since I have worked on this particular
> >> > application).
> >> >
> >> >
> >> >
> >> > -- Eric
> >> >
> >> >
> >> >
> >> > On Sat, Dec 8, 2012 at 11:25 PM, Jordan Zimmerman <
> >> > [EMAIL PROTECTED]> wrote:
> >> >
> >> >> Why would it lose leadership? The only reason I can think of is if
> the
> >> ZK
> >> >> cluster goes down. In normal use, the ZK cluster won't go down (I
> >> assume
> >> >> you're running 3 or 5 instances).
> >> >>
> >> >> -JZ
> >> >>
> >> >> On Dec 8, 2012, at 8:17 PM, Eric Pederson <[EMAIL PROTECTED]> wrote:
> >> >>
> >> >>> During the time the task is running a cluster member could lose its
> >> >>> leadership.
> >> >>
> >> >>
> >>
> >>
> >
>

--
Henry Robinson
Software Engineer
Cloudera
415-994-6679
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Eric Pederson 2012-12-09, 05:00