HDFS-5677. Merge 1558217 from trunk

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1558220 13f79535-47bb-0310-9956-ffa450edef68

hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

@@ -440,6 +440,9 @@ Release 2.3.0 - UNRELEASED
     HDFS-5675. Add Mkdirs operation to NNThroughputBenchmark.
     (Plamen Jeliazkov via shv)
 
+    HDFS-5677. Need error checking for HA cluster configuration.
+    (Vincent Sheffer via cos)
+
   OPTIMIZATIONS
 
   BUG FIXES

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DFSUtil.java

@@ -579,6 +579,12 @@ public class DFSUtil {
       String address = getConfValue(defaultValue, suffix, conf, keys);
       if (address != null) {
         InetSocketAddress isa = NetUtils.createSocketAddr(address);
+        if (isa.isUnresolved()) {
+          LOG.warn("Namenode for " + nsId +
+                   " remains unresolved for ID " + nnId +
+                   ".  Check your hdfs-site.xml file to " +
+                   "ensure namenodes are configured properly.");
+        }
         ret.put(nnId, isa);
       }
     }