that is expected. You have configured a replication factor of 2.
This means you have the following partition distribution.
$ ./partitionDistribution.sh 4 4 2
Distribution:
P\N| N 0| N 1| N 2| N 3
P 1| L | F | - | -
P 2| - | L | F | -
P 3| - | - | L | F
P 4| F | - | - | L
Partitions per Node:
N 0: 2
N 1: 2
N 2: 2
N 3: 2
I guess you mean you bring Broker-0 down, since this is part of Partition one and four.
With an replication factor of 2 you can’t reach quorum anymore, which makes the partition unhealthy or unusable at this moment.
As recommendation I can say try to use an odd replication factor, even numbers don’t give you any benefit. See also this SO post. So use for example three as replication factor.
Hope that helps.
Other posts where I mentioned this:
Greets
Chris