Package org.apache.druid.server.coordinator.loading

Enum SegmentAction

java.lang.Object

java.lang.Enum<SegmentAction>

org.apache.druid.server.coordinator.loading.SegmentAction

All Implemented Interfaces:

Serializable, Comparable<SegmentAction>

public enum SegmentAction
extends Enum<SegmentAction>

Represents actions that can be performed on a server for a single segment.

The different action types can be used to prioritize items in a LoadQueuePeon.

Enum Constant Summary

Enum Constants

Enum Constant	Description
DROP	Drop a segment from a server.
LOAD	Load a segment on a server.
MOVE_FROM	Move a segment from this server to another.
MOVE_TO	Move a segment to this server.
REPLICATE	Load a replica of a segment on a server.

Method Summary

Modifier and Type	Method	Description
boolean	isLoad()	True only if this action loads a segment on a server, i.e.
static SegmentAction	valueOf(String name)	Returns the enum constant of this type with the specified name.
static SegmentAction[]	values()	Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

DROP

public static final SegmentAction DROP

Drop a segment from a server.

LOAD

public static final SegmentAction LOAD

Load a segment on a server. This should be used when trying to load a segment on a tier where it is currently unavailable (i.e. no replicas loaded). This action cannot be throttled by the replicationThrottleLimit.

REPLICATE

public static final SegmentAction REPLICATE

Load a replica of a segment on a server. This should be used when trying to load more replicas of a segment on a tier where it is already available (i.e. atleast one loaded replica).

This is different from LOAD in two ways:

• this action can be throttled by the replicationThrottleLimit
• it is given lower priority than LOAD on the load queue peon

For all other purposes, REPLICATE is treated the same as LOAD.

MOVE_TO

public static final SegmentAction MOVE_TO

Move a segment to this server.

MOVE_FROM

public static final SegmentAction MOVE_FROM

Move a segment from this server to another. This is essentially a pending DROP operation, which starts only when the corresponding MOVE_TO has succeded.

Method Detail

values

public static SegmentAction[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (SegmentAction c : SegmentAction.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static SegmentAction 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

isLoad

public boolean isLoad()

True only if this action loads a segment on a server, i.e. LOAD, REPLICATE or MOVE_TO.