[ 
https://issues.apache.org/jira/browse/KAFKA-986?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13721095#comment-13721095
 ] 

Jay Kreps commented on KAFKA-986:
---------------------------------

I can't reproduce this. Here is what I am doing.

I am using 0.8 beta1.

bin/zookeeper-server-start.sh config/zookeeper.properties
bin/kafka-server-start.sh config/server.properties
bin/kafka-create-topic.sh --topic log --partition 2 --replica 1 --zookeeper 
localhost:2181

Now I start two consumers in two different shells:
bin/kafka-console-consumer.sh --zookeeper localhost:2181 --topic log --group 
my-group
bin/kafka-console-consumer.sh --zookeeper localhost:2181 --topic log --group 
my-group

Now I start the console producer and send a few test messages:
bin/kafka-console-producer.sh --broker-list localhost:9092 --topic log --sync
test 1
test 2
test 3
test 4
test 5
test 6
test 7

One console 1 I see the following:
test 1
test 3
test 5
test 7
On console 2 I see:
test 2
test 4
test 6
                
> Topic Consumption Across multiple instances of consumer groups
> --------------------------------------------------------------
>
>                 Key: KAFKA-986
>                 URL: https://issues.apache.org/jira/browse/KAFKA-986
>             Project: Kafka
>          Issue Type: Bug
>          Components: consumer
>    Affects Versions: 0.8
>         Environment: Linux
>            Reporter: Subbu Srinivasan
>            Assignee: Neha Narkhede
>
> Folks,
> How can we simulate the notion of queues for consumers from multiple 
> instances?
> For eg: I have a topic log.
> From a single machine ( I tried from different machines also) I started two 
> consumers on same topic with same group id. Both the consumers get copes of 
> messages. 
> bin/kafka-console-consumer.sh --zookeeper kafka1:2181  --topic log --group 1
> bin/kafka-console-consumer.sh --zookeeper kafka1:2181  --topic log --group 1
> From the design section at http://kafka.apache.org/design.html
> <clipped from there>
> Each consumer process belongs to a consumer group and each message is 
> delivered to exactly one process within every consumer group. Hence a 
> consumer group allows many processes or machines to logically act as a single 
> consumer. The concept of consumer group is very powerful and can be used to 
> support the semantics of either a queue or topic as found in JMS. To support 
> queue semantics, we can put all consumers in a single consumer group, in 
> which case each message will go to a single consumer. 
> </clipped from there>
> Can someone elaborate on this?
> Thanks

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira

Reply via email to