Kafka consumer getting duplicate message

[Ghosh, Achintya (Contractor)]

Hi there,

We are using Kafka 1.0.0.M2 with Spring and we see a lot of duplicate message 
is getting received by the Listener onMessage() method .
We configured :

enable.auto.commit=false
session.timeout.ms=15000
factory.getContainerProperties().setSyncCommits(true);
factory.setConcurrency(5);

So what could be the reason to get the duplicate messages?

Thanks
Achintya