0.17.3 has just been released. You can download it here. This is another bug fix release with minor enhancements (listed here). This upgrade is highly recommended to all
Note, when upgrading to this release, due to a bug in previous 0.17.x versions, it is recommended to run flush against all indices before shutting down the cluster (or doing a rolling restart) if “delete_by_query” is used against specific types.