Thanks Josh for your insights. That distinction between unit tests and dtests—especially in relation to intra-node vs. multi-node behavior—really helps clarify things. I’ll take another look at the patch and work on writing appropriate test cases accordingly, potentially shifting towards an in-jvm dtest as you suggested.
Regarding the PR access: do I need to take any additional steps to make it accessible? I had marked it as a draft PR since the test cases were still pending, so perhaps that’s affecting visibility. Thanks again for the guidance. Best Regards Manish On Tue, May 13, 2025 at 4:05 PM Josh McKenzie <jmcken...@apache.org> wrote: > Given the title on 20291: "Batch queries timeout when private IP of a node > fails in multi-dc Cassandra setup", this seems like a prime candidate for > an in-jvm dtest. The way I think about it: if I need to exercise intra-node > communication or functionality to confirm that something operates the way I > think it does, dtest it is. If whatever I'm testing has functionality > purely encapsulated by the operations of a single node (changes to storage > formats, in-memory representation, etc), then a unit test is fine. > > More often nowadays it ends up being a combination of: > > 1. property-testing on a class(es) > 2. integration testing on the node level (our historical "unit" test) > 3. then an in-jvm dtest to confirm multi-node operations, especially > in the presence of mixed version clusters (i.e. during upgrades) or > mixed-configuration features (i.e. rolling restart flipping flag to enable > a feature). > > I can't seem to access the PR on 20291 to give more insight or confirm, > but hopefully the above heuristic proves helpful. > > On Tue, May 13, 2025, at 3:38 AM, manish khandelwal wrote: > > Hi everyone > > I have a question regarding test strategy in Cassandra. Under what > circumstances is a dtest preferred over a unit test? Specifically, what > criteria should guide the decision to write a dtest instead of a unit test? > I’ve prepared a patch for *CASSANDRA-20291*, but I’m encountering some > challenges in writing unit tests—primarily due to the limited support for > mocking in the Cassandra codebase. As a result, I’m considering shifting > towards dtests and would appreciate any guidance on this. > Regards > Manish > > >
