HDDS-1896. Suppress WARN log from NetworkTopology#getDistanceCost. Contributed by Xiaoyu Yao. (#1214)

hadoop-hdds/common/src/main/java/org/apache/hadoop/hdds/scm/net/NetworkTopologyImpl.java

@@ -595,7 +595,7 @@ public class NetworkTopologyImpl implements NetworkTopology{
     try {
       if ((node1.getAncestor(maxLevel - 1) != clusterTree) ||
           (node2.getAncestor(maxLevel - 1) != clusterTree)) {
-        LOG.warn("One of the nodes is outside of network topology");
+        LOG.debug("One of the nodes is outside of network topology");
         return Integer.MAX_VALUE;
       }
       int level1 = node1.getLevel();