Please forgive another newbie question, but on this page on the Apache Druid site (https://druid.apache.org/technology) it talks about

Master nodes

,

Query nodes

, and

Data nodes

. Could someone explain the relationship between these and the services:

coordinator

,

overlord

,

router

,

broker

,

historical

, and

middle_manager

? Thank you!

Hello, The relationship is present in the schema in the page you linked. Query node (light purple) : broker & web console (=router) Master node (yellow or orange, not sure 😃 ) : coordinator (+overlord, these roles can be handled by the same node) & zookeeper & metastore Data nodes (blue) : historical & indexer (~= middle manager) Druid can be deployed in many configurations like 3 nodes (master, query, data) for simple uses cases to hundred (maybe thousands?) of nodes (for large volume of data/ingestion/query, HA...)

I did see some of those services in the diagram but it wasn't quite clear about the router, overlord, and middle manager. Your mappings helped a lot. Thank you!