druid/server
Gian Merlino a517f8ce49 Coordinator: Allow dropping all segments. (#7447)
Removes the coordinator sanity check that prevents it from dropping all
segments. It's useful to get rid of this, since the behavior is
unintuitive for dev/testing clusters where users might regularly want
to drop all their data to get back to a clean slate.

But the sanity check was there for a reason: to prevent a race condition
where the coordinator might drop all segments if it ran before the
first metadata store poll finished. This patch addresses that concern
differently, by allowing methods in MetadataSegmentManager to return
null if a poll has not happened yet, and canceling coordinator runs
in that case.

This patch also makes the "dataSources" reference in
SQLMetadataSegmentManager volatile. I'm not sure why it wasn't volatile
before, but it seems necessary to me: it's not final, and it's dereferenced
from multiple threads without synchronization.
2019-04-11 08:45:38 -07:00
..
src Coordinator: Allow dropping all segments. (#7447) 2019-04-11 08:45:38 -07:00
pom.xml Move GCP to a core extension (#6953) 2019-03-27 09:00:43 -07:00