You are viewing a plain text version of this content. The canonical link for it is here.
Posted to user@zookeeper.apache.org by harish lohar <hk...@gmail.com> on 2018/06/12 14:39:40 UTC

Kafka Failing to start due to existing ID

Hi All,

Need help regarding below scenario if any configuration is available to
help.

I have cluster of 6 nodes
3 Nodes are stopped and  brought up again, kafka fails to restart since
broker ID are still present in zookeeper znode /broker/ids/

Since the cluster goes down after removing 3 Nodes , session timeout
doesn't happen.

Though i am aware about TTL feature in zookeeper , but how to make sure
kafka creates znodes with TTL

Thanks
Harish

Re: Kafka Failing to start due to existing ID

Posted by Andor Molnár <an...@apache.org>.
Hi Harish,


I have a few questions to get some insight about your issue.

1. Why do run ZooKeeper with 6 nodes while odd number of nodes are 
recommended (not an issue really, just for curiousity),

2. Does Kafka support ZK 3.5+ with TTL nodes?

I think this is more of a Kafka question, but afaik Kafka doesn't run 
and cannot take advantage of 3.5 only features of ZK. Maybe I'm wrong, 
but I think it has some cleanup mechanism to delete expired broker ids 
or you must wait for the session to expire.


Regards,

Andor


On 06/12/2018 04:39 PM, harish lohar wrote:
> Hi All,
>
> Need help regarding below scenario if any configuration is available to
> help.
>
> I have cluster of 6 nodes
> 3 Nodes are stopped and  brought up again, kafka fails to restart since
> broker ID are still present in zookeeper znode /broker/ids/
>
> Since the cluster goes down after removing 3 Nodes , session timeout
> doesn't happen.
>
> Though i am aware about TTL feature in zookeeper , but how to make sure
> kafka creates znodes with TTL
>
> Thanks
> Harish
>


Re: Kafka Failing to start due to existing ID

Posted by harish lohar <hk...@gmail.com>.
Just to update everyone, finally i was able to root cause the issue and it
seems to be

https://issues.apache.org/jira/browse/ZOOKEEPER-2901

which is related to node id  being > 127.

it's fixed in 3.5.4-beta and it works fine.

Thanks
Harish


On Wed, Jun 13, 2018 at 7:42 AM Andor Molnar <an...@cloudera.com> wrote:

> Hi Harish,
>
> I see 2 things which need to be clarified here:
>
> 1. ZooKeeper session dies in 2 cases only: when client explicitly closes
> the session (which is *not* equivalent to disconnection) or session timeout
> expires,
> 2. If quorum is not present, there'll be no updates committed and clients
> are rejected to connect, so Kafka shouldn't be able to use the cluster.
>
> Similarly, when quorum comes back online, ZooKeeper will continue operating
> normally: it receives client connections, performs updates and expire
> sessions if necessary.
>
> I still believe therefore that your Kafka setup doesn't properly cleanup
> znodes for some reason, but I'm not a Kafka expert.
>
> Regards,
> Andor
>
>
>
>
> On Wed, Jun 13, 2018 at 12:34 AM, harish lohar <hk...@gmail.com> wrote:
>
> > Exactly , so in a case where there is jo quotum and no update can be
> made ,
> > is there a way yo stop kafka failing to start.
> >
> > One way is to cleanup kafka related znodes  after bringing up quorum and
> > then starting kafka.
> >
> > I was looking to avoid this.
> >
> >
> > On Tue, Jun 12, 2018 at 4:59 PM Brian Lininger <brian.lininger@veeva.com
> >
> > wrote:
> >
> > > Hi Harish,
> > > I think I see what may be the problem for you.  Based on your initial
> > > description (6 ZK nodes, 3 down) I think the problem is that you no
> > longer
> > > have a quorum.  When a Zookeeper cluster is running, updates (i.e.
> > removing
> > > znodes) can only occur when Zookeeper has a quorum, which 50.1% of the
> > > configured Zookeeper nodes.  If I understand correctly, then in your
> case
> > > you have 6 Zookeeper nodes configured but 3 are down.  This means that
> > you
> > > only have 50.0% of the Zookeeper cluster working, and thus Zookeeper
> does
> > > not have a quorum so no updates can be made.  I don't know much about
> the
> > > new TTL feature in 3.5, but my assumption is that it works on this same
> > > principle which is that no updates can be made to the cluster's znodes
> > when
> > > there is no quorum.  The same applies to the 3 Zookeeper node cluster,
> > you
> > > must have 2 nodes running to form a quorum and allow any updates to
> > occur.
> > >
> > > Please correct me if I missed something....
> > >
> > > Thanks,
> > > Brian
> > >
> > >
> > > On Tue, Jun 12, 2018 at 1:33 PM, harish lohar <hk...@gmail.com>
> wrote:
> > >
> > >> ---------- Forwarded message ---------
> > >> From: harish lohar <hk...@gmail.com>
> > >> Date: Tue, Jun 12, 2018 at 3:26 PM
> > >> Subject: Re: Kafka Failing to start due to existing ID
> > >> To: <an...@apache.org>
> > >>
> > >>
> > >> Hi Andor,
> > >>
> > >> Thanks for your reply.
> > >>
> > >> This issue is irrespective of number of nodes, even should be seen
> with
> > 3
> > >> Node cluster as well.
> > >>
> > >> Actually kafka has session_timeout config , but that seems to be in
> > effect
> > >> only if zookeeper cluster is up i.e. if kafka goes down when zookeeper
> > >> cluster is up.
> > >>
> > >> Now let's say if 2 nodes of Zookeeper cluster is down , and then if
> > kafka
> > >> connected to 3rd Zookeeper Node goes down zookeeper cluster doesn't
> > >> refresh
> > >> the session for Kafka connected to 3rd Node.
> > >>
> > >> So when other Node comes up and zookeeper cluster becomes available it
> > >> doesn't delete the id of the kafka which went down when zookeeper
> > cluster
> > >> was down.
> > >>
> > >> Regarding TTL I have already enquired the kafka forum and awaiting
> > reply.
> > >>
> > >> Ideally once zookeper cluster is up , it should delete the kafka
> broker
> > >> id's which are not connected which doesn't seem to be happening
> > >>
> > >> I hope I am making some sense :)
> > >>
> > >> Thanks
> > >> harish
> > >>
> > >>
> > >>
> > >> On Tue, Jun 12, 2018 at 2:59 PM Andor Molnár <an...@apache.org>
> wrote:
> > >>
> > >> > Hi Harish,
> > >> >
> > >> >
> > >> > I have a few questions to get some insight about your issue.
> > >> >
> > >> > 1. Why do run ZooKeeper with 6 nodes while odd number of nodes are
> > >> > recommended (not an issue really, just for curiousity),
> > >> >
> > >> > 2. Does Kafka support ZK 3.5+ with TTL nodes?
> > >> >
> > >> > I think this is more of a Kafka question, but afaik Kafka doesn't
> run
> > >> and
> > >> > cannot take advantage of 3.5 only features of ZK. Maybe I'm wrong,
> > but I
> > >> > think it has some cleanup mechanism to delete expired broker ids or
> > you
> > >> > must wait for the session to expire.
> > >> >
> > >> >
> > >> > Regards,
> > >> >
> > >> > Andor
> > >> >
> > >> >
> > >> >
> > >> > On 06/12/2018 04:39 PM, harish lohar wrote:
> > >> >
> > >> > Hi All,
> > >> >
> > >> > Need help regarding below scenario if any configuration is available
> > to
> > >> > help.
> > >> >
> > >> > I have cluster of 6 nodes
> > >> > 3 Nodes are stopped and  brought up again, kafka fails to restart
> > since
> > >> > broker ID are still present in zookeeper znode /broker/ids/
> > >> >
> > >> > Since the cluster goes down after removing 3 Nodes , session timeout
> > >> > doesn't happen.
> > >> >
> > >> > Though i am aware about TTL feature in zookeeper , but how to make
> > sure
> > >> > kafka creates znodes with TTL
> > >> >
> > >> > Thanks
> > >> > Harish
> > >> >
> > >> >
> > >> >
> > >> >
> > >>
> > >
> > >
> > >
> > > --
> > >
> > > [image: Veeva Systems - Zinc Team]
> > >
> > > *Brian Lininger*
> > > Technical Architect, Infrastructure & Search
> > > *Veeva Systems *
> > > brian.lininger@veeva.com
> > > www.veeva.com
> > >
> > > *This email and the information it contains are intended for the
> intended
> > > recipient only, are confidential and may be privileged information
> exempt
> > > from disclosure by law.*
> > > *If you have received this email in error, please notify us immediately
> > by
> > > reply email and delete this message from your computer.*
> > > *Please do not retain, copy or distribute this email.*
> > >
> >
>

Re: Kafka Failing to start due to existing ID

Posted by Andor Molnar <an...@cloudera.com>.
Hi Harish,

I see 2 things which need to be clarified here:

1. ZooKeeper session dies in 2 cases only: when client explicitly closes
the session (which is *not* equivalent to disconnection) or session timeout
expires,
2. If quorum is not present, there'll be no updates committed and clients
are rejected to connect, so Kafka shouldn't be able to use the cluster.

Similarly, when quorum comes back online, ZooKeeper will continue operating
normally: it receives client connections, performs updates and expire
sessions if necessary.

I still believe therefore that your Kafka setup doesn't properly cleanup
znodes for some reason, but I'm not a Kafka expert.

Regards,
Andor




On Wed, Jun 13, 2018 at 12:34 AM, harish lohar <hk...@gmail.com> wrote:

> Exactly , so in a case where there is jo quotum and no update can be made ,
> is there a way yo stop kafka failing to start.
>
> One way is to cleanup kafka related znodes  after bringing up quorum and
> then starting kafka.
>
> I was looking to avoid this.
>
>
> On Tue, Jun 12, 2018 at 4:59 PM Brian Lininger <br...@veeva.com>
> wrote:
>
> > Hi Harish,
> > I think I see what may be the problem for you.  Based on your initial
> > description (6 ZK nodes, 3 down) I think the problem is that you no
> longer
> > have a quorum.  When a Zookeeper cluster is running, updates (i.e.
> removing
> > znodes) can only occur when Zookeeper has a quorum, which 50.1% of the
> > configured Zookeeper nodes.  If I understand correctly, then in your case
> > you have 6 Zookeeper nodes configured but 3 are down.  This means that
> you
> > only have 50.0% of the Zookeeper cluster working, and thus Zookeeper does
> > not have a quorum so no updates can be made.  I don't know much about the
> > new TTL feature in 3.5, but my assumption is that it works on this same
> > principle which is that no updates can be made to the cluster's znodes
> when
> > there is no quorum.  The same applies to the 3 Zookeeper node cluster,
> you
> > must have 2 nodes running to form a quorum and allow any updates to
> occur.
> >
> > Please correct me if I missed something....
> >
> > Thanks,
> > Brian
> >
> >
> > On Tue, Jun 12, 2018 at 1:33 PM, harish lohar <hk...@gmail.com> wrote:
> >
> >> ---------- Forwarded message ---------
> >> From: harish lohar <hk...@gmail.com>
> >> Date: Tue, Jun 12, 2018 at 3:26 PM
> >> Subject: Re: Kafka Failing to start due to existing ID
> >> To: <an...@apache.org>
> >>
> >>
> >> Hi Andor,
> >>
> >> Thanks for your reply.
> >>
> >> This issue is irrespective of number of nodes, even should be seen with
> 3
> >> Node cluster as well.
> >>
> >> Actually kafka has session_timeout config , but that seems to be in
> effect
> >> only if zookeeper cluster is up i.e. if kafka goes down when zookeeper
> >> cluster is up.
> >>
> >> Now let's say if 2 nodes of Zookeeper cluster is down , and then if
> kafka
> >> connected to 3rd Zookeeper Node goes down zookeeper cluster doesn't
> >> refresh
> >> the session for Kafka connected to 3rd Node.
> >>
> >> So when other Node comes up and zookeeper cluster becomes available it
> >> doesn't delete the id of the kafka which went down when zookeeper
> cluster
> >> was down.
> >>
> >> Regarding TTL I have already enquired the kafka forum and awaiting
> reply.
> >>
> >> Ideally once zookeper cluster is up , it should delete the kafka broker
> >> id's which are not connected which doesn't seem to be happening
> >>
> >> I hope I am making some sense :)
> >>
> >> Thanks
> >> harish
> >>
> >>
> >>
> >> On Tue, Jun 12, 2018 at 2:59 PM Andor Molnár <an...@apache.org> wrote:
> >>
> >> > Hi Harish,
> >> >
> >> >
> >> > I have a few questions to get some insight about your issue.
> >> >
> >> > 1. Why do run ZooKeeper with 6 nodes while odd number of nodes are
> >> > recommended (not an issue really, just for curiousity),
> >> >
> >> > 2. Does Kafka support ZK 3.5+ with TTL nodes?
> >> >
> >> > I think this is more of a Kafka question, but afaik Kafka doesn't run
> >> and
> >> > cannot take advantage of 3.5 only features of ZK. Maybe I'm wrong,
> but I
> >> > think it has some cleanup mechanism to delete expired broker ids or
> you
> >> > must wait for the session to expire.
> >> >
> >> >
> >> > Regards,
> >> >
> >> > Andor
> >> >
> >> >
> >> >
> >> > On 06/12/2018 04:39 PM, harish lohar wrote:
> >> >
> >> > Hi All,
> >> >
> >> > Need help regarding below scenario if any configuration is available
> to
> >> > help.
> >> >
> >> > I have cluster of 6 nodes
> >> > 3 Nodes are stopped and  brought up again, kafka fails to restart
> since
> >> > broker ID are still present in zookeeper znode /broker/ids/
> >> >
> >> > Since the cluster goes down after removing 3 Nodes , session timeout
> >> > doesn't happen.
> >> >
> >> > Though i am aware about TTL feature in zookeeper , but how to make
> sure
> >> > kafka creates znodes with TTL
> >> >
> >> > Thanks
> >> > Harish
> >> >
> >> >
> >> >
> >> >
> >>
> >
> >
> >
> > --
> >
> > [image: Veeva Systems - Zinc Team]
> >
> > *Brian Lininger*
> > Technical Architect, Infrastructure & Search
> > *Veeva Systems *
> > brian.lininger@veeva.com
> > www.veeva.com
> >
> > *This email and the information it contains are intended for the intended
> > recipient only, are confidential and may be privileged information exempt
> > from disclosure by law.*
> > *If you have received this email in error, please notify us immediately
> by
> > reply email and delete this message from your computer.*
> > *Please do not retain, copy or distribute this email.*
> >
>

Re: Kafka Failing to start due to existing ID

Posted by harish lohar <hk...@gmail.com>.
Exactly , so in a case where there is jo quotum and no update can be made ,
is there a way yo stop kafka failing to start.

One way is to cleanup kafka related znodes  after bringing up quorum and
then starting kafka.

I was looking to avoid this.


On Tue, Jun 12, 2018 at 4:59 PM Brian Lininger <br...@veeva.com>
wrote:

> Hi Harish,
> I think I see what may be the problem for you.  Based on your initial
> description (6 ZK nodes, 3 down) I think the problem is that you no longer
> have a quorum.  When a Zookeeper cluster is running, updates (i.e. removing
> znodes) can only occur when Zookeeper has a quorum, which 50.1% of the
> configured Zookeeper nodes.  If I understand correctly, then in your case
> you have 6 Zookeeper nodes configured but 3 are down.  This means that you
> only have 50.0% of the Zookeeper cluster working, and thus Zookeeper does
> not have a quorum so no updates can be made.  I don't know much about the
> new TTL feature in 3.5, but my assumption is that it works on this same
> principle which is that no updates can be made to the cluster's znodes when
> there is no quorum.  The same applies to the 3 Zookeeper node cluster, you
> must have 2 nodes running to form a quorum and allow any updates to occur.
>
> Please correct me if I missed something....
>
> Thanks,
> Brian
>
>
> On Tue, Jun 12, 2018 at 1:33 PM, harish lohar <hk...@gmail.com> wrote:
>
>> ---------- Forwarded message ---------
>> From: harish lohar <hk...@gmail.com>
>> Date: Tue, Jun 12, 2018 at 3:26 PM
>> Subject: Re: Kafka Failing to start due to existing ID
>> To: <an...@apache.org>
>>
>>
>> Hi Andor,
>>
>> Thanks for your reply.
>>
>> This issue is irrespective of number of nodes, even should be seen with 3
>> Node cluster as well.
>>
>> Actually kafka has session_timeout config , but that seems to be in effect
>> only if zookeeper cluster is up i.e. if kafka goes down when zookeeper
>> cluster is up.
>>
>> Now let's say if 2 nodes of Zookeeper cluster is down , and then if kafka
>> connected to 3rd Zookeeper Node goes down zookeeper cluster doesn't
>> refresh
>> the session for Kafka connected to 3rd Node.
>>
>> So when other Node comes up and zookeeper cluster becomes available it
>> doesn't delete the id of the kafka which went down when zookeeper cluster
>> was down.
>>
>> Regarding TTL I have already enquired the kafka forum and awaiting reply.
>>
>> Ideally once zookeper cluster is up , it should delete the kafka broker
>> id's which are not connected which doesn't seem to be happening
>>
>> I hope I am making some sense :)
>>
>> Thanks
>> harish
>>
>>
>>
>> On Tue, Jun 12, 2018 at 2:59 PM Andor Molnár <an...@apache.org> wrote:
>>
>> > Hi Harish,
>> >
>> >
>> > I have a few questions to get some insight about your issue.
>> >
>> > 1. Why do run ZooKeeper with 6 nodes while odd number of nodes are
>> > recommended (not an issue really, just for curiousity),
>> >
>> > 2. Does Kafka support ZK 3.5+ with TTL nodes?
>> >
>> > I think this is more of a Kafka question, but afaik Kafka doesn't run
>> and
>> > cannot take advantage of 3.5 only features of ZK. Maybe I'm wrong, but I
>> > think it has some cleanup mechanism to delete expired broker ids or you
>> > must wait for the session to expire.
>> >
>> >
>> > Regards,
>> >
>> > Andor
>> >
>> >
>> >
>> > On 06/12/2018 04:39 PM, harish lohar wrote:
>> >
>> > Hi All,
>> >
>> > Need help regarding below scenario if any configuration is available to
>> > help.
>> >
>> > I have cluster of 6 nodes
>> > 3 Nodes are stopped and  brought up again, kafka fails to restart since
>> > broker ID are still present in zookeeper znode /broker/ids/
>> >
>> > Since the cluster goes down after removing 3 Nodes , session timeout
>> > doesn't happen.
>> >
>> > Though i am aware about TTL feature in zookeeper , but how to make sure
>> > kafka creates znodes with TTL
>> >
>> > Thanks
>> > Harish
>> >
>> >
>> >
>> >
>>
>
>
>
> --
>
> [image: Veeva Systems - Zinc Team]
>
> *Brian Lininger*
> Technical Architect, Infrastructure & Search
> *Veeva Systems *
> brian.lininger@veeva.com
> www.veeva.com
>
> *This email and the information it contains are intended for the intended
> recipient only, are confidential and may be privileged information exempt
> from disclosure by law.*
> *If you have received this email in error, please notify us immediately by
> reply email and delete this message from your computer.*
> *Please do not retain, copy or distribute this email.*
>

Re: Kafka Failing to start due to existing ID

Posted by Brian Lininger <br...@veeva.com>.
Hi Harish,
I think I see what may be the problem for you.  Based on your initial
description (6 ZK nodes, 3 down) I think the problem is that you no longer
have a quorum.  When a Zookeeper cluster is running, updates (i.e. removing
znodes) can only occur when Zookeeper has a quorum, which 50.1% of the
configured Zookeeper nodes.  If I understand correctly, then in your case
you have 6 Zookeeper nodes configured but 3 are down.  This means that you
only have 50.0% of the Zookeeper cluster working, and thus Zookeeper does
not have a quorum so no updates can be made.  I don't know much about the
new TTL feature in 3.5, but my assumption is that it works on this same
principle which is that no updates can be made to the cluster's znodes when
there is no quorum.  The same applies to the 3 Zookeeper node cluster, you
must have 2 nodes running to form a quorum and allow any updates to occur.

Please correct me if I missed something....

Thanks,
Brian


On Tue, Jun 12, 2018 at 1:33 PM, harish lohar <hk...@gmail.com> wrote:

> ---------- Forwarded message ---------
> From: harish lohar <hk...@gmail.com>
> Date: Tue, Jun 12, 2018 at 3:26 PM
> Subject: Re: Kafka Failing to start due to existing ID
> To: <an...@apache.org>
>
>
> Hi Andor,
>
> Thanks for your reply.
>
> This issue is irrespective of number of nodes, even should be seen with 3
> Node cluster as well.
>
> Actually kafka has session_timeout config , but that seems to be in effect
> only if zookeeper cluster is up i.e. if kafka goes down when zookeeper
> cluster is up.
>
> Now let's say if 2 nodes of Zookeeper cluster is down , and then if kafka
> connected to 3rd Zookeeper Node goes down zookeeper cluster doesn't refresh
> the session for Kafka connected to 3rd Node.
>
> So when other Node comes up and zookeeper cluster becomes available it
> doesn't delete the id of the kafka which went down when zookeeper cluster
> was down.
>
> Regarding TTL I have already enquired the kafka forum and awaiting reply.
>
> Ideally once zookeper cluster is up , it should delete the kafka broker
> id's which are not connected which doesn't seem to be happening
>
> I hope I am making some sense :)
>
> Thanks
> harish
>
>
>
> On Tue, Jun 12, 2018 at 2:59 PM Andor Molnár <an...@apache.org> wrote:
>
> > Hi Harish,
> >
> >
> > I have a few questions to get some insight about your issue.
> >
> > 1. Why do run ZooKeeper with 6 nodes while odd number of nodes are
> > recommended (not an issue really, just for curiousity),
> >
> > 2. Does Kafka support ZK 3.5+ with TTL nodes?
> >
> > I think this is more of a Kafka question, but afaik Kafka doesn't run and
> > cannot take advantage of 3.5 only features of ZK. Maybe I'm wrong, but I
> > think it has some cleanup mechanism to delete expired broker ids or you
> > must wait for the session to expire.
> >
> >
> > Regards,
> >
> > Andor
> >
> >
> >
> > On 06/12/2018 04:39 PM, harish lohar wrote:
> >
> > Hi All,
> >
> > Need help regarding below scenario if any configuration is available to
> > help.
> >
> > I have cluster of 6 nodes
> > 3 Nodes are stopped and  brought up again, kafka fails to restart since
> > broker ID are still present in zookeeper znode /broker/ids/
> >
> > Since the cluster goes down after removing 3 Nodes , session timeout
> > doesn't happen.
> >
> > Though i am aware about TTL feature in zookeeper , but how to make sure
> > kafka creates znodes with TTL
> >
> > Thanks
> > Harish
> >
> >
> >
> >
>



-- 

[image: Veeva Systems - Zinc Team]

*Brian Lininger*
Technical Architect, Infrastructure & Search
*Veeva Systems *
brian.lininger@veeva.com
www.veeva.com

*This email and the information it contains are intended for the intended
recipient only, are confidential and may be privileged information exempt
from disclosure by law.*
*If you have received this email in error, please notify us immediately by
reply email and delete this message from your computer.*
*Please do not retain, copy or distribute this email.*

Fwd: Kafka Failing to start due to existing ID

Posted by harish lohar <hk...@gmail.com>.
---------- Forwarded message ---------
From: harish lohar <hk...@gmail.com>
Date: Tue, Jun 12, 2018 at 3:26 PM
Subject: Re: Kafka Failing to start due to existing ID
To: <an...@apache.org>


Hi Andor,

Thanks for your reply.

This issue is irrespective of number of nodes, even should be seen with 3
Node cluster as well.

Actually kafka has session_timeout config , but that seems to be in effect
only if zookeeper cluster is up i.e. if kafka goes down when zookeeper
cluster is up.

Now let's say if 2 nodes of Zookeeper cluster is down , and then if kafka
connected to 3rd Zookeeper Node goes down zookeeper cluster doesn't refresh
the session for Kafka connected to 3rd Node.

So when other Node comes up and zookeeper cluster becomes available it
doesn't delete the id of the kafka which went down when zookeeper cluster
was down.

Regarding TTL I have already enquired the kafka forum and awaiting reply.

Ideally once zookeper cluster is up , it should delete the kafka broker
id's which are not connected which doesn't seem to be happening

I hope I am making some sense :)

Thanks
harish



On Tue, Jun 12, 2018 at 2:59 PM Andor Molnár <an...@apache.org> wrote:

> Hi Harish,
>
>
> I have a few questions to get some insight about your issue.
>
> 1. Why do run ZooKeeper with 6 nodes while odd number of nodes are
> recommended (not an issue really, just for curiousity),
>
> 2. Does Kafka support ZK 3.5+ with TTL nodes?
>
> I think this is more of a Kafka question, but afaik Kafka doesn't run and
> cannot take advantage of 3.5 only features of ZK. Maybe I'm wrong, but I
> think it has some cleanup mechanism to delete expired broker ids or you
> must wait for the session to expire.
>
>
> Regards,
>
> Andor
>
>
>
> On 06/12/2018 04:39 PM, harish lohar wrote:
>
> Hi All,
>
> Need help regarding below scenario if any configuration is available to
> help.
>
> I have cluster of 6 nodes
> 3 Nodes are stopped and  brought up again, kafka fails to restart since
> broker ID are still present in zookeeper znode /broker/ids/
>
> Since the cluster goes down after removing 3 Nodes , session timeout
> doesn't happen.
>
> Though i am aware about TTL feature in zookeeper , but how to make sure
> kafka creates znodes with TTL
>
> Thanks
> Harish
>
>
>
>