org.apache.druid.server.coordinator

Class ServerHolder

java.lang.Object

org.apache.druid.server.coordinator.ServerHolder

All Implemented Interfaces:

Comparable<ServerHolder>

public class ServerHolder
extends Object
implements Comparable<ServerHolder>

Encapsulates the state of a DruidServer during a single coordinator run.

ServerHolders are naturally ordered by available size, servers with more available size first.

Constructor Summary

Constructors

Constructor and Description
ServerHolder(ImmutableDruidServer server, LoadQueuePeon peon)
ServerHolder(ImmutableDruidServer server, LoadQueuePeon peon, boolean isDecommissioning)
ServerHolder(ImmutableDruidServer server, LoadQueuePeon peon, boolean isDecommissioning, int maxSegmentsInLoadQueue, int maxLifetimeInQueue) Creates a new ServerHolder valid for a single coordinator run.

Method Summary

Modifier and Type	Method and Description
boolean	cancelOperation(SegmentAction action, DataSegment segment)
boolean	canLoadSegment(DataSegment segment) Checks if the server can load the given segment.
int	compareTo(ServerHolder serverHolder)
boolean	equals(Object o)
SegmentAction	getActionOnSegment(DataSegment segment)
long	getAvailableSize()
List<DataSegment>	getLoadingSegments() Segments that are currently in the queue for being loaded on this server.
long	getMaxSize()
int	getNumLoadingReplicas()
int	getNumMovingSegments()
LoadQueuePeon	getPeon()
double	getPercentUsed()
SegmentCountsPerInterval	getProjectedSegments() Segments that are expected to be loaded on this server once all the operations in progress have completed.
Map<DataSegment,SegmentAction>	getQueuedSegments() Segments queued for load, drop or move on this server.
Collection<DataSegment>	getServedSegments() Segments that are currently loaded on this server.
ImmutableDruidServer	getServer()
long	getSizeUsed()
int	hashCode()
boolean	hasSegmentLoaded(SegmentId segmentId)
boolean	isDecommissioning()
boolean	isDroppingSegment(DataSegment segment)
boolean	isLoadingSegment(DataSegment segment)
boolean	isProjectedSegment(DataSegment segment)
boolean	isRealtimeServer()
boolean	isServingSegment(DataSegment segment) Returns true if this server has the segment loaded and is not dropping it.
boolean	startOperation(SegmentAction action, DataSegment segment)
String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

ServerHolder

public ServerHolder(ImmutableDruidServer server,
                    LoadQueuePeon peon)

ServerHolder

public ServerHolder(ImmutableDruidServer server,
                    LoadQueuePeon peon,
                    boolean isDecommissioning)

ServerHolder

public ServerHolder(ImmutableDruidServer server,
                    LoadQueuePeon peon,
                    boolean isDecommissioning,
                    int maxSegmentsInLoadQueue,
                    int maxLifetimeInQueue)

Creates a new ServerHolder valid for a single coordinator run.

Parameters:

server - Underlying Druid server

peon - Load queue peon for this server

isDecommissioning - Whether the server is decommissioning

maxSegmentsInLoadQueue - Max number of segments that can be present in the load queue at any point. If this is 0, the load queue can have an unlimited number of segments.

maxLifetimeInQueue - Number of coordinator runs after a which a segment in load/drop queue is considered to be stuck.

Method Detail

getServer

public ImmutableDruidServer getServer()

getPeon

public LoadQueuePeon getPeon()

getMaxSize

public long getMaxSize()

getSizeUsed

public long getSizeUsed()

getPercentUsed

public double getPercentUsed()

isDecommissioning

public boolean isDecommissioning()

getAvailableSize

public long getAvailableSize()

canLoadSegment

public boolean canLoadSegment(DataSegment segment)

Checks if the server can load the given segment.

A load is possible only if the server meets all of the following criteria:

• is not being decommissioned
• is not already serving the segment
• is not performing any other action on the segment
• has not already exceeded the load queue limit in this run
• has available disk space

getActionOnSegment

public SegmentAction getActionOnSegment(DataSegment segment)

getQueuedSegments

public Map<DataSegment,SegmentAction> getQueuedSegments()

Segments queued for load, drop or move on this server.

• Contains segments present in the queue when the current coordinator run started.
• Contains segments added to the queue during the current run.
• Maps replicating segments to LOAD rather than REPLICATE for simplicity.
• Does not contain segments whose actions were cancelled.

getProjectedSegments

public SegmentCountsPerInterval getProjectedSegments()

Segments that are expected to be loaded on this server once all the operations in progress have completed.

isProjectedSegment

public boolean isProjectedSegment(DataSegment segment)

getLoadingSegments

public List<DataSegment> getLoadingSegments()

Segments that are currently in the queue for being loaded on this server. This does not include segments that are being moved to this server.

getServedSegments

public Collection<DataSegment> getServedSegments()

Segments that are currently loaded on this server.

isServingSegment

public boolean isServingSegment(DataSegment segment)

Returns true if this server has the segment loaded and is not dropping it.

isLoadingSegment

public boolean isLoadingSegment(DataSegment segment)

isDroppingSegment

public boolean isDroppingSegment(DataSegment segment)

getNumMovingSegments

public int getNumMovingSegments()

getNumLoadingReplicas

public int getNumLoadingReplicas()

startOperation

public boolean startOperation(SegmentAction action,
                              DataSegment segment)

cancelOperation

public boolean cancelOperation(SegmentAction action,
                               DataSegment segment)

hasSegmentLoaded

public boolean hasSegmentLoaded(SegmentId segmentId)

isRealtimeServer

public boolean isRealtimeServer()

compareTo

public int compareTo(ServerHolder serverHolder)

Specified by:

compareTo in interface Comparable<ServerHolder>

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object