org.apache.druid.server.coordinator.loading

Class StrategicSegmentAssigner

java.lang.Object

org.apache.druid.server.coordinator.loading.StrategicSegmentAssigner

All Implemented Interfaces:

SegmentActionHandler

public class StrategicSegmentAssigner
extends Object
implements SegmentActionHandler

Used by the coordinator in each run for segment loading, dropping, balancing and broadcasting.

An instance of this class is freshly created for each coordinator run.

Constructor Summary

Constructors

Constructor and Description
StrategicSegmentAssigner(SegmentLoadQueueManager loadQueueManager, DruidCluster cluster, BalancerStrategy strategy, SegmentLoadingConfig loadingConfig, CoordinatorRunStats stats)

Method Summary

Modifier and Type	Method and Description
void	broadcastSegment(DataSegment segment) Broadcasts the given segment to all servers that are broadcast targets.
void	deleteSegment(DataSegment segment) Marks the given segment as unused.
SegmentReplicationStatus	getReplicationStatus()
CoordinatorRunStats	getStats()
void	makeAlerts()
boolean	moveSegment(DataSegment segment, ServerHolder sourceServer, List<ServerHolder> destinationServers) Moves the given segment from the source server to an eligible destination server.
void	replicateSegment(DataSegment segment, Map<String,Integer> tierToReplicaCount) Queues load or drop of replicas of the given segment to achieve the target replication level on all historical tiers.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

StrategicSegmentAssigner

public StrategicSegmentAssigner(SegmentLoadQueueManager loadQueueManager,
                                DruidCluster cluster,
                                BalancerStrategy strategy,
                                SegmentLoadingConfig loadingConfig,
                                CoordinatorRunStats stats)

Method Detail

getStats

public CoordinatorRunStats getStats()

getReplicationStatus

public SegmentReplicationStatus getReplicationStatus()

makeAlerts

public void makeAlerts()

moveSegment

public boolean moveSegment(DataSegment segment,
                           ServerHolder sourceServer,
                           List<ServerHolder> destinationServers)

Moves the given segment from the source server to an eligible destination server.

An eligible destination server must:

• be present in the given list of destination servers
• belong to the same tier as the source server
• not already be serving or loading a replica of the segment
• have enough space to load the segment

The segment is not moved if:

• there is no eligible destination server
• or segment is already optimally placed
• or some other error occurs

replicateSegment

public void replicateSegment(DataSegment segment,
                             Map<String,Integer> tierToReplicaCount)

Description copied from interface: SegmentActionHandler

Queues load or drop of replicas of the given segment to achieve the target replication level on all historical tiers.

Specified by:

replicateSegment in interface SegmentActionHandler

broadcastSegment

public void broadcastSegment(DataSegment segment)

Description copied from interface: SegmentActionHandler

Broadcasts the given segment to all servers that are broadcast targets.

Specified by:

broadcastSegment in interface SegmentActionHandler

deleteSegment

public void deleteSegment(DataSegment segment)

Description copied from interface: SegmentActionHandler

Marks the given segment as unused. Unused segments are eventually unloaded from all servers and deleted from metadata as well as deep storage.

Specified by:

deleteSegment in interface SegmentActionHandler