piotrrzysko commented on pull request #9315: URL: https://github.com/apache/kafka/pull/9315#issuecomment-697717628
@jolshan @mumrah Thanks for the review! Of course, I agree with you that it would be nice to use the mock in all tests, but after rethinking the solution suggested in this PR I came to the conclusion that it is not so easy. I assumed that `InetAddress#getAllByName` is the only place where DNS resolution happens - it’s not true. The constructor of `InetSocketAddress` that is used by `ClientUtils#parseAndValidateAddresses` in some circumstances (when a passed hostname is a machine name rather than a literal IP address) may also call an external DNS server. This behavior is much harder to mock. Perhaps it is not a problem for tests from `ClientUtilsTest`, because as I checked only `localhost` is resolved in this way. However, I wouldn’t like to introduce abstraction over DNS resolving mechanism that is unable to cover all cases. Unfortunately, the only solution that comes to my mind is to try a hack based on reflection that will allow replacing the default DNS provider in tests. It was something that I wanted to avoid because it can cause problems with future versions of Java. Nevertheless, I can check if it is possible and how ugly it will be :). WDYT? ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org