Hi Devs,
I would like to start a discussion on FLIP-363: Unify the Representation of
TaskManager Location in REST API and Web UI [1].
The TaskManager location of subtasks is important for identifying TM-related
problems. There are a number of places in REST API and Web UI where TaskManager
location is returned/displayed.
Problems:
* Only hostname is provided to represent TaskManager location in some
places (e.g. SubtaskCurrentAttemptDetailsHandler). However, in a containerized
era, it is common to have multiple TMs on the same host, and port info is
crucial to distinguish different TMs.
* Inconsistent naming of the field to represent TaskManager location:
"host" is used in most places but "location" is also used in
JobExceptions-related places.
* Inconsistent semantics of the "host" field: The semantics of the host
field are inconsistent, sometimes it denotes hostname only while in other times
it denotes hostname + port (which is also inconsistent with the name of "host").
We propose to improve the current situation by:
* Use a field named "location" that represents TaskManager location in the
form of "${hostname}:${port}" in a consistent manner across REST APIs and the
front-end.
* Rename the column name from "Host" to "Location" on the Web UI to reflect
the change that both hostname and port are displayed.
* Keep the old "host" fields untouched for compatibility. They can be
removed in the next major version.
Looking forward to your feedback.
[1] FLIP-363: Unify the Representation of TaskManager Location in REST API and
Web UI - Apache Flink - Apache Software
Foundation<https://cwiki.apache.org/confluence/display/FLINK/FLIP-363%3A+Unify+the+Representation+of+TaskManager+Location+in+REST+API+and+Web+UI>
Best,
Zhanghao Chen
