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


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Re: leader election, scheduled tasks, losing leadership
Eric Pederson 2012-12-09, 04:56
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.
>> >>
>> >>
>>
>>
>