Does min.insync.replica configuration affect Kafka producer throughput?

Question

From kafka documentation

When a producer sets acks to "all" (or "-1"), this min.insync.replica configuration specifies the minimum number of replicas that must acknowledge a write for the write to be considered successful.

It says when the minimum number of in-sync replicas acknowledge, the write is successful but when i run performance test with min.insync.replica as 1 and 3 (for a topic of partition=1 and R.F=5 in 5 broker setup), the performance of kafka producer, with acks='all', is same.

So, Does min.insync.replica per-topic configuration affects Kafka producer throughput (ran in isolation) with acks="all" ?

Answer 1

If you use acks='all', the leader waits until in-sync replicas get the message before sending back an acknowledgment or an error, so the performance is affected. In case of min.insync.replica=1, the producer gets a response back once the message is written to the leader. It should be faster than using min.insync.replica=3 as in this case the producer waits for 2 replicas to get all the messages before it can consider the message as committed.

Your results mean that the latency between your brokers is very low. I believe you should see the difference if you start the brokers in different datacenters/regions.