Yes, a partition can be accessed by only a single thread at a time, so that second consumer of yours, since it's in the same group, has nothing to do. If you add more partitions your consumers would help each other consume all messages out of that topic (roughly 50% of messages each). If you were to assign the second consumer with a different group, each consumer would consume all messages (independently of one another).
BTW, Kafka is not broadcasting anything, your consumers are pulling messages out of Kafka :) Marko Bonaći Monitoring | Alerting | Anomaly Detection | Centralized Log Management Solr & Elasticsearch Support Sematext <http://sematext.com/> | Contact <http://sematext.com/about/contact.html> On Fri, Apr 29, 2016 at 12:18 PM, paresh <pare...@glam.com> wrote: > Hi Team, > > Can anybody help with issue I am facing with running multiple consumer > instances on single topic having single partition? > > Kafka is broadcasting messages to all the consumers though all consumers > are running in same group > I am using kafka-php client lib to connect with kafka server and using > socket connect (Encoder/Decoder) for connecting consumer and producer. > > Regards, > Paresh Behede >