Package org.apache.druid.discovery

Interface Summary

Interface	Description
DruidLeaderSelector	Interface for supporting Overlord and Coordinator Leader Elections in TaskMaster and DruidCoordinator which expect appropriate implementation available in guice annotated with @IndexingService and @Coordinator respectively.
DruidLeaderSelector.Listener
DruidNodeAnnouncer	DiscoveryDruidNode announcer for internal discovery.
DruidNodeDiscovery	Interface for discovering Druid nodes announced by DruidNodeAnnouncer.
DruidNodeDiscovery.Listener	Listener for watching nodes in a DruidNodeDiscovery instance obtained via DruidNodeDiscoveryProvider.getXXX().

Class Summary

Class	Description
DataNodeService	Metadata announced by any node that serves segments.
DiscoveryDruidNode	Representation of all information related to discovery of a node and all the other metadata associated with the node per nodeRole such as broker, historical etc.
DruidLeaderClient	This class facilitates interaction with Coordinator/Overlord leader nodes.
DruidNodeDiscoveryProvider	Provider of DruidNodeDiscovery instances.
DruidService	Metadata of a service announced by node.
LookupNodeService	Metadata announced by any node that serves queries and hence applies lookups.
WorkerNodeService	Worker metadata announced by Middle Manager.

Enum Summary

Enum	Description
NodeRole	This is a historical occasion that this enum is different from ServerType (also called "node type" in various places) because they are essentially the same abstraction, but merging them could only increase the complexity and drop the code safety, because they name the same types differently ("peon" - "indexer-executor" and "middleManager" - "realtime") and both expose them via JSON APIs.