Package org.apache.druid.server.coordinator.duty

Class PrepareBalancerAndLoadQueues

java.lang.Object

org.apache.druid.server.coordinator.duty.PrepareBalancerAndLoadQueues

All Implemented Interfaces:

CoordinatorDuty

public class PrepareBalancerAndLoadQueues
extends Object
implements CoordinatorDuty

This duty does the following:

• Creates an immutable DruidCluster consisting of ServerHolders which represent the current state of the servers in the cluster.
• Starts and stops load peons for new and disappeared servers respectively.
• Cancels in-progress loads on all decommissioning servers. This is done here to ensure that under-replicated segments are assigned to active servers in the RunRules duty after this.
• Initializes the BalancerStrategy for the run.

Constructor Summary

Constructors

Constructor	Description
PrepareBalancerAndLoadQueues(LoadQueueTaskMaster taskMaster, SegmentLoadQueueManager loadQueueManager, BalancerStrategyFactory balancerStrategyFactory, ServerInventoryView serverInventoryView)

Method Summary

Modifier and Type	Method	Description
DruidCoordinatorRuntimeParams	run(DruidCoordinatorRuntimeParams params)	Implementations of this method run various activities performed by the coordinator.

Methods inherited from class java.lang.Object

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

Constructor Details

PrepareBalancerAndLoadQueues

public PrepareBalancerAndLoadQueues(LoadQueueTaskMaster taskMaster,
 SegmentLoadQueueManager loadQueueManager,
 BalancerStrategyFactory balancerStrategyFactory,
 ServerInventoryView serverInventoryView)

Method Details

run

public DruidCoordinatorRuntimeParams run(DruidCoordinatorRuntimeParams params)

Description copied from interface: CoordinatorDuty

Implementations of this method run various activities performed by the coordinator. Input params can be used and modified. The returned DruidCoordinatorRuntimeParams is passed to the next duty.

Specified by:

run in interface CoordinatorDuty

Returns:

same as input or a modified value to be used by next duty. Null return values will prevent subsequent CoordinatorDuty objects (see the order in the lists passed into the constructor of DruidCoordinator.DutiesRunnable) from running until the next cycle.