According to the discussion on the dev mailing list ([SURVEY] Remove Mesos support and [VOTE] Deprecating Mesos support), the community decided to deprecate Mesos support in Apache Flink (see (RESULT)[VOTE]Deprecating Mesos support).
This issue covers adding corresponding warnings/notices:
- Log statements - Mesos-related ClusterEntrypoint implementations
- Warning in the docs
- @Deprecated in relevant classes