org.apache.druid.server.coordinator.balancer

Class ReservoirSegmentSampler

java.lang.Object

org.apache.druid.server.coordinator.balancer.ReservoirSegmentSampler

public final class ReservoirSegmentSampler
extends Object

Method Summary

Modifier and Type	Method and Description
static List<BalancerSegmentHolder>	pickMovableSegmentsFrom(List<ServerHolder> serverHolders, int maxSegmentsToPick, Function<ServerHolder,Collection<DataSegment>> segmentProvider, Set<String> broadcastDatasources) Picks segments from the given set of servers that can be moved to other servers for balancing.

Methods inherited from class java.lang.Object

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

Method Detail

pickMovableSegmentsFrom

public static List<BalancerSegmentHolder> pickMovableSegmentsFrom(List<ServerHolder> serverHolders,
                                                                  int maxSegmentsToPick,
                                                                  Function<ServerHolder,Collection<DataSegment>> segmentProvider,
                                                                  Set<String> broadcastDatasources)

Picks segments from the given set of servers that can be moved to other servers for balancing.

Parameters:

serverHolders - Set of historicals to consider for picking segments

maxSegmentsToPick - Maximum number of segments to pick

segmentProvider - Function to extract all movable segments from a ServerHolder.

broadcastDatasources - Segments belonging to these datasources will not be picked for balancing, since they should be loaded on all servers anyway.

Returns:

Iterator over BalancerSegmentHolders, each of which contains a segment picked for moving and the server from which it was picked.