As it became apparent in #15819, we don't have tests for the upgrade of a cluster from one version to another. I believe we have a "mixed version" acceptance test, but I think all it does is it writes data using an old version and reads it with a new one.
We should have a test checking the interoperability of versions in a running cluster. We should test that as many operations as possible work when the operation involves nodes on different versions. Examples of things to test: DistSQL reads, replication, lease transfers.
In the specific case of #15819, what would have helped is one with a (lease-related?) Raft command being proposed by the new version and applied by the old one.
Jira issue: CRDB-6080
As it became apparent in #15819, we don't have tests for the upgrade of a cluster from one version to another. I believe we have a "mixed version" acceptance test, but I think all it does is it writes data using an old version and reads it with a new one.
We should have a test checking the interoperability of versions in a running cluster. We should test that as many operations as possible work when the operation involves nodes on different versions. Examples of things to test: DistSQL reads, replication, lease transfers.
In the specific case of #15819, what would have helped is one with a (lease-related?) Raft command being proposed by the new version and applied by the old one.
Jira issue: CRDB-6080