zookeeper-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Jordan Zimmerman <jor...@jordanzimmerman.com>
Subject Re: leader election, scheduled tasks, losing leadership
Date Sun, 09 Dec 2012 04:57:25 GMT
lol - I have an open bug for LeaderLatch. hasLeadership() is returning true when the cluster
becomes unstable: https://github.com/Netflix/curator/issues/216 - In any event, you should
register a ConnectionStateListener in case the cluster loses quorum.

-JZ

On Dec 8, 2012, at 8:54 PM, Eric Pederson <ericacm@gmail.com> wrote:

> I am using Curator LeaderLatch :)
> 
> 
> -- Eric
> 
> 
> 
> On Sat, Dec 8, 2012 at 11:52 PM, Jordan Zimmerman <
> jordan@jordanzimmerman.com> 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 <ericacm@gmail.com> 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 <
>>> jordan@jordanzimmerman.com> 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 <ericacm@gmail.com> wrote:
>>>> 
>>>>> During the time the task is running a cluster member could lose its
>>>>> leadership.
>>>> 
>>>> 
>> 
>> 


Mime
  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message