PrepareBalancerAndLoadQueues (druid-server 29.0.1 API)

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

All Methods Instance Methods Concrete Methods
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 Detail
  - PrepareBalancerAndLoadQueues
```
public PrepareBalancerAndLoadQueues(LoadQueueTaskMaster taskMaster,
                                    SegmentLoadQueueManager loadQueueManager,
                                    BalancerStrategyFactory balancerStrategyFactory,
                                    ServerInventoryView serverInventoryView)
```
- Method Detail
  - 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.