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Zookeeper, mail # user - RE: About initLimit and syncLimit


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Re: About initLimit and syncLimit
Patrick Hunt 2012-10-06, 14:41
Say you have a very large datastore (the snapshot file is very large).
It can take considerable time for the leader to communicate the znode
data to the followers during startup. initLimit is the amount of time
the leader will allow the followers to d/l the data from the leader
and get to a point where they are ready to server requests to clients.
If this time is exceeded the leader will close the connection to the
follower and the quorum process will restart. 20 sec is typically more
than enough time, however if you have a slow connection or the data is
very large it might be necessary to increase this. For example I've
seen some cases of users storing 100's of gb in their datastore, in
which case the initLimit needed to be increased. However in most cases
this is not necessary.

The syncLimit controls the amount of time the quorum members will
allow each other to communicate. If the leader doesn't hear from a
follower in the syncLimit time it will drop the follower from the
quorum, and vice versa. It's important not to set this parameter too
high as it's one of the ways a server detects networking issues and
causes recovery to take place (ie the follower will drop out of the
quorum and try to reconnect, all clients on that follower will
disconnect and reconnect to another server, etc...)

Patrick

On Thu, Oct 4, 2012 at 2:17 AM, charles charles <[EMAIL PROTECTED]> wrote:
> Yeah, I maybe the same problem! Maybe we misunderstand the initLimit and syncLimit.Please check for me: 1. Leader will wait for follow 10*tickTime to do such things: connect to leader,  and sync the lasted data from leader. But, if the time follow load snap data from local disk is included in 10*tickTime?
>  A: load snap data from local disk,
>  B: conn to leader
>  C: sync lasted data from leader.
>
>  Maybe, you can tell me,  10*tickTime includes which part?
> A   or  B+C or A+B+C
>
> 2. While in runtime, if follow's state too far behind a leadr, even to 3*tickTime, the follow will be dropped.
>
>
> Others, please check my understanding
>  > Date: Tue, 25 Sep 2012 03:48:47 -0700
>> From: [EMAIL PROTECTED]
>> To: [EMAIL PROTECTED]
>> Subject: RE: About initLimit and syncLimit
>>
>> Hi,
>>
>>  Even I am facing this issue. But I dont want to clean up the data
>> directory, Is there any other way of solving this issue?? Please let me know
>> as soon as possible.
>>
>> Regards,
>> Ramachandra
>>
>>
>>
>> --
>> View this message in context: http://zookeeper-user.578899.n2.nabble.com/Re-Zookeeper-cluster-failing-tp7577972p7577980.html
>> Sent from the zookeeper-user mailing list archive at Nabble.com.
>