MM2: is connectCluster must be same as targetCluster

[tulequ]

I have some question about mirrormaker2
As the title, is connectCluster must be same as targetCluster?
If so, why don't remove connectCluster?

And how to configure more than one targetCluster as below?

To me, document is not clear enough to figure it out

  connectCluster: kk-dev2
  clusters:
    - alias: kk-dev1
    - alias: kk-dev2
    - alias: kk-dev3

  mirrors:
    - sourceCluster: kk-dev1
      targetCluster: kk-dev2
    - sourceCluster: kk-dev2
      targetCluster: kk-dev1
    - sourceCluster: kk-dev2
      targetCluster: kk-dev3

Thank for help

[scholzj]

In a short ... It cannot be removed. And you cannot set-up the mirroring as you try above with a single Mirror Maker instance.

Kafka Mirror Maker 2 in Strimzi runs on top of distributed Kafka Connect. The connectCluster field defines, which of the clusters will be used as a the one where the Kafka Connect will connect to. And since the Mirror Maker connectors are source connectors only (meaning they can consume from remote clusters and publish to the local cluster where Connect is connected), it has to be the target cluster.

So you can have multiple source clusters, but only one target cluster per MM2 instance. To do what you have above, you would need to have 3 separate MM2 instances: one for each target cluster. (TBH, not sure if such loop mirroring as you have there really works anyway, but that is a separate question I guess)

[tulequ]

I'm clear now, thank you for clarifying