Coordinator-overlord replica count in cluster deployment


is there any recommended replica for coordinator and overlord , we tested with 1 and 2 replica there are not much except leader and worker .
What is use of keeping 2 coordinator ?

This is for high availability, so you don’t have an outage if the overlord’s or coordinator’s goes down. Druid uses typical quorum methods to elect leaders, so, for the usual reasons, you actually want 3, not 1 or 2. (With 2, if one goes down, the other can’t get quorum agreement, so it won’t become a leader. This is also typical, to avoid split-brain scenarios, where two nodes both think they’re leader.)


Also (I know this is late…) but you also get to do rolling upgrades…