Why MirrorMaker2 doesn't respect default.replication.factor while creating mirrored topics ?

[yxw]

Our Kafka clusters (MSK) is configured default.replication.factor = 3, and we expect topics are created with this default replication factor unless explicitly set otherwise.

However, when deployed Strimzi MirrorMaker2, the mirrored topics are always created with replication.factor as 2. This causes discrepancy because our source topics have replication factor 3.

Understand that the MirrorMaker2 [document] (https://github.com/strimzi/strimzi-kafka-operator/blob/release-0.35.x/documentation/modules/configuring/con-config-mirrormaker2-connectors.adoc) explicitly says that replication.factor default is 2.

Just wondering, is there any rational here why replication.factor defaults to 2, regardless the fact that:

1. default.replication.factor is 3, and
2. other topics (heartbeat, checkpoint) has default value of 3

Thanks!