Consumers in a consumer group not owning partitions
I have a consumer group with five consumers, but only three are consuming.
The topic has 25 partitions (5 brokers with 5 partitions each one), so it
shouldn't be the problem the partitions quantity.
In zookeeper, I see the five consumers in /consumers/$GROUP/ids, but in
/consumers/$GROUP/owners only three of them are owning partitions.
If I restart the consumers, the first three to win the race, can get the
partitions, and the other two don't get anything.
I´m using Kafka 0.7.1.
What could it be happening?