operator upgrade from 0.42 to 0.51

[sgv0007]

Hi team,

Is it possible to directly upgrade from strimzi version 0.42 , kafka -3.7.1 to strimzi version 0.51, kafka-4.2.0 or not ?

When I tried to test this upgrade path, as soon as operator was upgraded it started throwing error that broker version is not supported and the kafka CR status changed to not ready .

I immediately deployed new kafka version with all the CRD changes but the operator was unable to perform the upgrade. I saw some message in operator logs that it is unable to reach the controller.

[ppatierno]

One of the reasons it's not possible is because you starts from a version where your cluster is ZooKeeper based and you want to land into a version where both operator and Kafka doesn't have ZooKeeper anymore but only KRaft.
You have to go through the 0.45.2 release, running your KRaft migration, from ZooKeeper to KRaft and then moving forward with the upgrade path.

[sgv0007]

@ppatierno Already I have migrated to KRaft mode . is it still not possible?

[scholzj]

@sgv0007 I'm afraid that we do not have the resources to test every single combination of versions for upgrade tests. 0.42 -> 0.51 is almost 2 years of developemnt. So if it does not work, there is probably some change that breaks things and you need to go in smaller steps. I think you should be able to go from 0.42 to 0.45. And I did some manual testing of 0.45 to 0.51. So you might be able to make a large jump there. But please try it first in some test environment. Also, if 0.45.2 is what you use, please read the release note in https://github.com/strimzi/strimzi-kafka-operator/releases/tag/0.45.2 about the upgrade from 0.45.2 to 0.51.

[sgv0007]

@scholzj Thanks