An example implementation <https://reviews.apache.org/r/23863/> of an
announcer is now available. It can be enabled with the --announcer-enable
and --announce-ensemble flags passed to the Aurora executor. There is a
ticket <https://issues.apache.org/jira/browse/AURORA-598> open to make
passing command line flags to the executor easier, but in the meantime this
can be accomplished using a wrapper script or by building your own custom
executor with the flag defaults overridden.
The example Announcer announces via Zookeeper using the ServerSet protocol.
Jobs specifying an 'announce' attribute are announced into the zookeeper
tree at /aurora/{{role}}/{{environment}}/{{name}}. Announcing consists of
writing an ephemeral/sequential znode containing information about instance
id and ports allocated by the task.
More information about ServerSets and client libraries for them can be
found in the user guide here:
https://github.com/apache/incubator-aurora/blob/master/docs/user-guide.md#user-content-service-discovery
More information about controlling the mapping of ports and how they're
announced can be found in the configuration reference:
https://github.com/apache/incubator-aurora/blob/master/docs/configuration-reference.md#announcer-objects
This work does not preclude alternate announcer implementations -- instead
it demonstrates how one can add an announcing mechanism using the
status_providers API in the AuroraExecutor.
If you have any questions, don't hesitate to ask.
Thanks,
~brian
