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Posted to users@kafka.apache.org by Monika Garg <ga...@gmail.com> on 2013/11/19 08:16:49 UTC
ActiveControllerCount is always will be either 0 or 1 in 3 nodes
kafka cluster?
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*
Re: ActiveControllerCount is always will be either 0 or 1 in 3 nodes
kafka cluster?
Posted by Monika Garg <ga...@gmail.com>.
Ohh...that is the case.I never think that way that in a running cluster
there can be no active controller.Yes you are right,it will be a bug then.
On Nov 19, 2013 6:02 PM, "Neha Narkhede" <ne...@gmail.com> wrote:
> 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 <ga...@gmail.com> 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 <neha.narkhede@gmail.com
> > >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" <ga...@gmail.com> 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 <
> > neha.narkhede@gmail.com
> > > > >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 <
> gargmoni03@gmail.com>
> > > > > 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*
> >
>
Re: ActiveControllerCount is always will be either 0 or 1 in 3 nodes
kafka cluster?
Posted by Neha Narkhede <ne...@gmail.com>.
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 <ga...@gmail.com> 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 <neha.narkhede@gmail.com
> >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" <ga...@gmail.com> 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 <
> neha.narkhede@gmail.com
> > > >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 <ga...@gmail.com>
> > > > 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*
>
Re: ActiveControllerCount is always will be either 0 or 1 in 3 nodes
kafka cluster?
Posted by Monika Garg <ga...@gmail.com>.
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 <ne...@gmail.com>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" <ga...@gmail.com> 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 <neha.narkhede@gmail.com
> > >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 <ga...@gmail.com>
> > > 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*
Re: ActiveControllerCount is always will be either 0 or 1 in 3 nodes
kafka cluster?
Posted by Neha Narkhede <ne...@gmail.com>.
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" <ga...@gmail.com> 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 <neha.narkhede@gmail.com
> >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 <ga...@gmail.com>
> > 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*
>
Re: ActiveControllerCount is always will be either 0 or 1 in 3 nodes
kafka cluster?
Posted by Monika Garg <ga...@gmail.com>.
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 <ne...@gmail.com>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 <ga...@gmail.com>
> 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*
Re: ActiveControllerCount is always will be either 0 or 1 in 3 nodes
kafka cluster?
Posted by Neha Narkhede <ne...@gmail.com>.
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 <ga...@gmail.com> 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*
>