Package org.apache.druid.server.coordinator.balancer

Class DiskNormalizedCostBalancerStrategy

java.lang.Object
org.apache.druid.server.coordinator.balancer.CostBalancerStrategy
org.apache.druid.server.coordinator.balancer.DiskNormalizedCostBalancerStrategy
All Implemented Interfaces:
BalancerStrategy
public class DiskNormalizedCostBalancerStrategy extends CostBalancerStrategy
A BalancerStrategy which can be used when historicals in a tier have varying disk capacities. This strategy normalizes the cost of placing a segment on a server as calculated by CostBalancerStrategy by doing the following:
  • Divide the cost by the number of segments on the server. This ensures that cost does not increase just because the number of segments on a server is higher.
  • Multiply the resulting value by disk usage ratio. This ensures that all hosts have equivalent levels of percentage disk utilization.
i.e. to place a segment on a given server 
 cost = as computed by CostBalancerStrategy
 normalizedCost = (cost / numSegments) * usageRatio
                = (cost / numSegments) * (diskUsed / totalDiskSpace)

  • Constructor Details

    • DiskNormalizedCostBalancerStrategy

      public DiskNormalizedCostBalancerStrategy(com.google.common.util.concurrent.ListeningExecutorService exec)

  • Method Details