HBASE-26327 Replicas cohosted on a rack shouldn't keep triggering Balancer

Author: clarax

hbase-balancer/src/main/java/org/apache/hadoop/hbase/master/balancer/StochasticLoadBalancer.java

@@ -310,14 +310,7 @@ void updateMetricsSize(int size) {
 
   private boolean areSomeRegionReplicasColocated(BalancerClusterState c) {
     regionReplicaHostCostFunction.prepare(c);
-    if (Math.abs(regionReplicaHostCostFunction.cost()) > CostFunction.COST_EPSILON) {
-      return true;
-    }
-    regionReplicaRackCostFunction.prepare(c);
-    if (Math.abs(regionReplicaRackCostFunction.cost()) > CostFunction.COST_EPSILON) {
-      return true;
-    }
-    return false;
+    return Math.abs(regionReplicaHostCostFunction.cost()) > CostFunction.COST_EPSILON);
   }
 
   private String getBalanceReason(double total, double sumMultiplier) {