Package org.apache.druid.server.coordination

Enum ServerType

java.lang.Object
java.lang.Enum<ServerType>
org.apache.druid.server.coordination.ServerType
All Implemented Interfaces:
Serializable, Comparable<ServerType>
public enum ServerType extends Enum<ServerType>
This enum represents types of druid services that hold segments.

These types are externally visible (e.g., from the output of ServersResource.makeSimpleServer(org.apache.druid.client.DruidServer)).

For backwards compatibility, when presenting these types externally, the toString() representation of the enum should be used.

The toString() method converts the enum name() to lowercase and replaces underscores with hyphens, which is the format expected for the server type string prior to the patch that introduced ServerType: https://github.com/apache/druid/pull/4148 This is a historical occasion that this enum is different from NodeRole 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 ("indexer-executor" - "peon" and "realtime" - "middleManager") and both expose them via JSON APIs. These abstractions can probably be merged when Druid updates to Jackson 2.9 that supports JsonAliases, see see https://github.com/apache/druid/issues/7152.

  • Enum Constant Details

    • HISTORICAL

      public static final ServerType HISTORICAL

    • BRIDGE

      public static final ServerType BRIDGE

    • INDEXER_EXECUTOR

      public static final ServerType INDEXER_EXECUTOR

    • REALTIME

      public static final ServerType REALTIME

    • BROKER

      public static final ServerType BROKER

  • Method Details

    • values

      public static ServerType[] values()
      Returns an array containing the constants of this enum type, in the order they are declared.
      Returns:
      an array containing the constants of this enum type, in the order they are declared

    • valueOf

      public static ServerType valueOf(String name)
      Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)
      Parameters:
      name - the name of the enum constant to be returned.
      Returns:
      the enum constant with the specified name
      Throws:
      IllegalArgumentException - if this enum type has no constant with the specified name
      NullPointerException - if the argument is null

    • isSegmentReplicationTarget

      public abstract boolean isSegmentReplicationTarget()
      Indicates this type of node is able to be a target of segment replication.
      Returns:
      true if it is available for replication
      See Also:

    • isSegmentBroadcastTarget

      public boolean isSegmentBroadcastTarget()
      Indicates this type of node is able to be a target of segment broadcast.
      Returns:
      true if it is available for broadcast.

    • isSegmentServer

      public abstract boolean isSegmentServer()
      Indicates this type of node is serving segments that are meant to be the target of fan-out by a Broker. Nodes that return "true" here are often referred to as "data servers" or "data server processes".

    • fromString

      public static ServerType fromString(String type)

    • fromNodeRole

      public static ServerType fromNodeRole(NodeRole nodeRole)

    • toString

      public String toString()
      Overrides:
      toString in class Enum<ServerType>