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Kafka >> mail # user >> ActiveControllerCount is always will be either 0 or 1 in 3 nodes kafka cluster?


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Re: ActiveControllerCount is always will be either 0 or 1 in 3 nodes kafka cluster?
Sure, but this is to alert if there is no active controller when all
brokers are live, which points to a bug.

-Neha
On Tue, Nov 19, 2013 at 9:53 AM, Monika Garg <[EMAIL PROTECTED]> wrote:

> Thanks Neha,Now got your point completely.
>
> One more small thing that I want to understand:
>
> The case when mbean values for ActiveControllerCount
> across all brokers in a cluster != 1,will be only if all the brokers of the
> cluster are down and in that case it will not be possible to get the value
> of this Mbean from jconsole,as the jconsole will be disconnected if the
> Kafka service is down on the given jmxPort.
> So it will never be possible to get the value of the mentioned Mbean if all
> the brokers are down,so it will never be the case that you are
> mentioning.Please correct me if I am misunderstanding.
>
>
> On Tue, Nov 19, 2013 at 7:48 PM, Neha Narkhede <[EMAIL PROTECTED]
> >wrote:
>
> > Like I mentioned above, it is due to ease of alerting -
> >
> > " alert if the addition of the mbean values for ActiveControllerCount
> > across all brokers in a cluster != 1."
> >
> > It can be done with boolean as well, we found the addition rule to be
> > easier.
> >
> > Thanks,
> > Neha
> > On Nov 19, 2013 1:48 AM, "Monika Garg" <[EMAIL PROTECTED]> wrote:
> >
> > > Thanks for replying Neha.
> > > Yes I got the same thing as u written:There should only be one
> controller
> > > at any point of time in a Kafka
> > > cluster. If that controller broker is bounced, then the controller
> moves
> > to
> > > another broker.
> > > But my doubt is this value will fluctuate always between 0 and 1 ,so it
> > > must be a boolean value and its name shouldn't be
> ActiveControllerCount.
> > >
> > >
> > > On Tue, Nov 19, 2013 at 1:15 PM, Neha Narkhede <
> [EMAIL PROTECTED]
> > > >wrote:
> > >
> > > > There should only be one controller at any point of time in a Kafka
> > > > cluster. If that controller broker is bounced, then the controller
> > moves
> > > to
> > > > another broker. In general, you want to alert if the addition of the
> > > mbean
> > > > values for ActiveControllerCount across all brokers in a cluster !=
> 1.
> > > >
> > > > Thanks,
> > > > Neha
> > > >
> > > >
> > > > On Mon, Nov 18, 2013 at 11:16 PM, Monika Garg <[EMAIL PROTECTED]>
> > > > wrote:
> > > >
> > > > > Hi,
> > > > >
> > > > > there is one Mbean in jconsole with name
> > > > >
> > "kafka.controller":type="KafkaController",name="ActiveControllerCount",
> > > > >
> > > > > the Value of this Mbean is always 1 on one broker and 0 on all
> others
> > > > > remaining broker of the 3 nodes kafka cluster.Will it always be
> like
> > > > this?
> > > > >
> > > > > As per my understanding it will always be 1 on one and only one
> > broker
> > > as
> > > > > there will be only one active controller in the cluster at any
> point
> > of
> > > > > time.
> > > > >
> > > > > So it should be "kafka.controller":type="KafkaController",name="
> > > > > *ActiveController*" and it sholud be a boolean value.
> > > > >
> > > > > Please correct if I am wrong.
> > > > >
> > > > > --
> > > > > *Moniii*
> > > > >
> > > >
> > >
> > >
> > >
> > > --
> > > *Moniii*
> > >
> >
>
>
>
> --
> *Moniii*
>