[jira] [Created] (KAFKA-3959) __consumer_offsets wrong number of replicas at startup

["Alban Hurtaud (JIRA)" <ji...@apache.org>]

Alban Hurtaud created KAFKA-3959:
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             Summary: __consumer_offsets wrong number of replicas at startup
                 Key: KAFKA-3959
                 URL: https://issues.apache.org/jira/browse/KAFKA-3959
             Project: Kafka
          Issue Type: Bug
          Components: consumer, offset manager, replication
    Affects Versions: 0.10.0.0, 0.9.0.1
         Environment: Brokers of 3 kafka nodes running Red Hat Enterprise Linux Server release 7.2 (Maipo)
            Reporter: Alban Hurtaud


When creating a stack of 3 kafka brokers, the consumer is starting faster than kafka nodes and when trying to read a topic, only one kafka node is available.
So the __consumer_offsets is created with a replication factor set to 1 (instead of configured 3) :

offsets.topic.replication.factor=3
default.replication.factor=3
min.insync.replicas=2

Then, other kafka nodes go up and we have exceptions because the replicas # for __consumer_offsets is 1 and min insync is 2. So exceptions are thrown.

What I missed is : Why the __consumer_offsets is topic is created with replication to 1 (when 1 broker is running) whereas in server.properties it is set to 3 ?

To reproduce : 
- Prepare 3 kafka nodes with the 3 lines above added to servers.properties.
- Run one kafka,
- Run one consumer (the __consumer_offsets is created with replicas =1)
- Run 2 more kafka nodes



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