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Posted to users@kafka.apache.org by Kamal <ka...@gmail.com> on 2017/11/24 07:19:44 UTC

Broker Already Registered Error

Hi Kafka Users,

    In our production cluster, we have faced the below error in 2 out of 3
brokers. After this error, the ISR are not updated and not able to create
new topics as the replication factor
is higher than the available brokers.

The session between Kafka and Zookeeper got expired. During reconnect, the
below error occurred:

*[2017-11-23 04:48:39,180] INFO Session establishment complete on server
x.x.x.76/x.x.x.76:10056, sessionid = 0x25fe606b0dd0000, negotiated timeout
= 20000 (org.apache.zookeeper.ClientCnxn*
*)*
*[2017-11-23 04:48:39,181] INFO zookeeper state changed (SyncConnected)
(org.I0Itec.zkclient.ZkClient)*
*[2017-11-23 04:48:39,183] INFO re-registering broker info in ZK for broker
3 (kafka.server.KafkaHealthcheck$SessionExpireListener)*
*[2017-11-23 04:48:39,183] INFO Creating /brokers/ids/3 (is it secure?
false) (kafka.utils.ZKCheckedEphemeral)*
*[2017-11-23 04:48:39,186] INFO Result of znode creation is: NODEEXISTS
(kafka.utils.ZKCheckedEphemeral)*
*[2017-11-23 04:48:39,186] ERROR Error handling event ZkEvent[New session
event sent to kafka.server.KafkaHealthcheck$SessionExpireListener@58b411d0]
(org.I0Itec.zkclient.ZkEventThread)*
*java.lang.RuntimeException: A broker is already registered on the path
/brokers/ids/3. This probably indicates that you either have configured a
brokerid that is already in use, or else you have shutdown this broker and
restarted it faster than the zookeeper timeout so it appears to be
re-registering.*
*        at kafka.utils.ZkUtils.registerBrokerInZk(ZkUtils.scala:408)*
*        at kafka.utils.ZkUtils.registerBrokerInZk(ZkUtils.scala:394)*
*        at
kafka.server.KafkaHealthcheck.register(KafkaHealthcheck.scala:71)*
*        at
kafka.server.KafkaHealthcheck$SessionExpireListener.handleNewSession(KafkaHealthcheck.scala:105)*
*        at org.I0Itec.zkclient.ZkClient$6.run(ZkClient.java:736)*
*        at org.I0Itec.zkclient.ZkEventThread.run(ZkEventThread.java:72)*


After this exception, all the ISR updates gets skipped.

*[2017-11-23 04:48:39,340] INFO New leader is 3
(kafka.server.ZookeeperLeaderElector$LeaderChangeListener)*
*[2017-11-23 04:49:00,008] INFO New leader is 2
(kafka.server.ZookeeperLeaderElector$LeaderChangeListener)*
*[2017-11-23 04:49:12,774] INFO Partition
[CHANNEL_CLIENT_LISTENER_CHANGE,0] on broker 3: Cached zkVersion [2] not
equal to that in zookeeper, skip updating ISR (kafka.cluster.Partition)*


Zookeeper is deployed in quorum mode (3 zk). In one of the Zookeeper, we
faced the below errors: (kafka-zk default session timeout: 20 s).
Other two Zk servers seems fine.

https://pastebin.com/9YQABiTL

Finally, we restarted the affected two brokers. We are using Kafka Version
- 0.10.2.1 and Zookeeper version - 3.4.9
Does these session errors are fixed in the latest version (1.0.0) / What
are the pre-cautionary steps to take to avoid these errors ?

Regards,
Kamal C

Re: Broker Already Registered Error

Posted by Kamal <ka...@gmail.com>.
With the `zookeeper-shell.sh` script, I have checked the path of
`/brokers/ids`, it showed only the broker id which was un-affected.

On Fri, Nov 24, 2017 at 12:49 PM, Kamal <ka...@gmail.com>
wrote:

> Hi Kafka Users,
>
>     In our production cluster, we have faced the below error in 2 out of 3
> brokers. After this error, the ISR are not updated and not able to create
> new topics as the replication factor
> is higher than the available brokers.
>
> The session between Kafka and Zookeeper got expired. During reconnect, the
> below error occurred:
>
> *[2017-11-23 04:48:39,180] INFO Session establishment complete on server
> x.x.x.76/x.x.x.76:10056, sessionid = 0x25fe606b0dd0000, negotiated timeout
> = 20000 (org.apache.zookeeper.ClientCnxn*
> *)*
> *[2017-11-23 04:48:39,181] INFO zookeeper state changed (SyncConnected)
> (org.I0Itec.zkclient.ZkClient)*
> *[2017-11-23 04:48:39,183] INFO re-registering broker info in ZK for
> broker 3 (kafka.server.KafkaHealthcheck$SessionExpireListener)*
> *[2017-11-23 04:48:39,183] INFO Creating /brokers/ids/3 (is it secure?
> false) (kafka.utils.ZKCheckedEphemeral)*
> *[2017-11-23 04:48:39,186] INFO Result of znode creation is: NODEEXISTS
> (kafka.utils.ZKCheckedEphemeral)*
> *[2017-11-23 04:48:39,186] ERROR Error handling event ZkEvent[New session
> event sent to kafka.server.KafkaHealthcheck$SessionExpireListener@58b411d0]
> (org.I0Itec.zkclient.ZkEventThread)*
> *java.lang.RuntimeException: A broker is already registered on the path
> /brokers/ids/3. This probably indicates that you either have configured a
> brokerid that is already in use, or else you have shutdown this broker and
> restarted it faster than the zookeeper timeout so it appears to be
> re-registering.*
> *        at kafka.utils.ZkUtils.registerBrokerInZk(ZkUtils.scala:408)*
> *        at kafka.utils.ZkUtils.registerBrokerInZk(ZkUtils.scala:394)*
> *        at
> kafka.server.KafkaHealthcheck.register(KafkaHealthcheck.scala:71)*
> *        at
> kafka.server.KafkaHealthcheck$SessionExpireListener.handleNewSession(KafkaHealthcheck.scala:105)*
> *        at org.I0Itec.zkclient.ZkClient$6.run(ZkClient.java:736)*
> *        at org.I0Itec.zkclient.ZkEventThread.run(ZkEventThread.java:72)*
>
>
> After this exception, all the ISR updates gets skipped.
>
> *[2017-11-23 04:48:39,340] INFO New leader is 3
> (kafka.server.ZookeeperLeaderElector$LeaderChangeListener)*
> *[2017-11-23 04:49:00,008] INFO New leader is 2
> (kafka.server.ZookeeperLeaderElector$LeaderChangeListener)*
> *[2017-11-23 04:49:12,774] INFO Partition
> [CHANNEL_CLIENT_LISTENER_CHANGE,0] on broker 3: Cached zkVersion [2] not
> equal to that in zookeeper, skip updating ISR (kafka.cluster.Partition)*
>
>
> Zookeeper is deployed in quorum mode (3 zk). In one of the Zookeeper, we
> faced the below errors: (kafka-zk default session timeout: 20 s).
> Other two Zk servers seems fine.
>
> https://pastebin.com/9YQABiTL
>
> Finally, we restarted the affected two brokers. We are using Kafka Version
> - 0.10.2.1 and Zookeeper version - 3.4.9
> Does these session errors are fixed in the latest version (1.0.0) / What
> are the pre-cautionary steps to take to avoid these errors ?
>
> Regards,
> Kamal C
>
>
>
>
>
>