I first have a single consumer node with 3 consumer threads and 12
partitions in kafka broker then if i check the owner in the consumer
offset checker the below is the result.
bin/kafka-run-class.sh kafka.tools.ConsumerOffsetChecker --group group1
--zkconnect zkhost:zkport --topic testtopic
Group Topic Pid Offset
logSize Lag Owner
group1 testtopic 0 253 253 0
group1_xxxx-1397216047177-6f419d28-0
group1 testtopic 1 268 268 0
group1_xxxx-1397216047177-6f419d28-0
group1 testtopic 2 258 258 0
group1_xxxx-1397216047177-6f419d28-0
group1 testtopic 3 265 265 0
group1_xxxx-1397216047177-6f419d28-0
group1 testtopic 4 262 262 0
group1_xxxx-1397216047177-6f419d28-1
group1 testtopic 5 296 296 0
group1_xxxx-1397216047177-6f419d28-1
group1 testtopic 6 248 248 0
group1_xxxx-1397216047177-6f419d28-1
group1 testtopic 7 272 272 0
group1_xxxx-1397216047177-6f419d28-1
group1 testtopic 8 242 242 0
group1_xxxx-1397216047177-6f419d28-2
group1 testtopic 9 263 263 0
group1_xxxx-1397216047177-6f419d28-2
group1 testtopic 10 294 294 0
group1_xxxx-1397216047177-6f419d28-2
group1 testtopic 11 254 254 0
group1_xxxx-1397216047177-6f419d28-2
as you see for all partitions owners are present.
Now i thought that the node is over burdned and i started one more node.
When i started the second node completely, then the output of the
consumer offset checker is as below
bin/kafka-run-class.sh kafka.tools.ConsumerOffsetChecker --group group1
--zkconnect zkhost:zkport --topic testtopic
Group Topic Pid Offset
logSize Lag Owner
group1 testtopic 0 253 253 0
group1_xxxx-1397216047177-6f419d28-0
group1 testtopic 1 268 268 0
group1_xxxx-1397216047177-6f419d28-0
group1 testtopic 2 258 258 0
group1_xxxx-1397216047177-6f419d28-1
group1 testtopic 3 265 265 0
group1_xxxx-1397216047177-6f419d28-1
group1 testtopic 4 262 262 0
group1_xxxx-1397216047177-6f419d28-2
group1 testtopic 5 296 296 0
group1_xxxx-1397216047177-6f419d28-2
group1 testtopic 6 248 248 0 none
group1 testtopic 7 272 272 0 none
group1 testtopic 8 242 242 0 none
group1 testtopic 9 263 263 0 none
group1 testtopic 10 294 294 0 none
group1 testtopic 11 254 254 0 none
It has reduced the burden but, the other partitions are not taken by any
node. Because of this messages going into those partitions are not
getting retrived.
The reason i found was there are some conflicts while taking up these
partitions by the second node, and after 10 retries, it just gave up.
I tried to restart the second node hoping, restart will make it take the
partitions but it was not. what is the best way out for me in this
scenario.
There are cases in our production where we may have to add consumers for
a particular topic, if adding consumers is going to result this, can
some one suggest a way out.
thanks
Arjun NArasimha kota
On Friday 11 April 2014 05:13 PM, Arjun wrote:
On the same lines when will the owner column of the result produced by
Consumer offset checker will be none?
and what will it signify? does it say that particualr partition is up
for grab but no one has taken it? why will this happen?
I know i may be asking some silly questions but can some one please
help me out here.
Thanks
Arjun Narasimha Kota
On Friday 11 April 2014 04:48 PM, Arjun wrote:
Some times, the error is even not printed. The blow line gets
printed(i increased the number of retires to 10)
end rebalancing consumer
group1_ip-10-122-57-66-1397214466042-81e47bfe try #9
and then the consumer just sits idle.
Thanks
Arjun Narasimha Kota
On Friday 11 April 2014 04:33 PM, Arjun wrote:
Once i get this exception
ERROR consumer.ZookeeperConsumerConnector: [xxxxxxxxxx ], error
during syncedRebalance
kafka.common.ConsumerRebalanceFailedException: xxxxxxxxx can't
rebalance after 4 retries
The consumer is not consuming any more messages. Is this the
behaviour? is there any property in high level consumer through
which i can say to consumer to keep retrying, until consumer gets
the data. This message is not atually being thrown in high level
consumer. This is just logged in the logger. If the consumer will
not get data after this exception, shouldn't this be thrown at a
place user can catch it and raise an alert?
Thanks
Arjun Narasimha Kota
