HDFS-4359. Slow RPC responses from NN can prevent metrics collection on DNs. Contributed by liang xie.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1435300 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -423,6 +423,9 @@ Release 2.0.3-alpha - Unreleased
     HDFS-4415. HostnameFilter should handle hostname resolution failures and
     continue processing. (Robert Kanter via atm)
 
+    HDFS-4359. Slow RPC responses from NN can prevent metrics collection on
+    DNs. (liang xie via atm)
+
   BREAKDOWN OF HDFS-3077 SUBTASKS
 
     HDFS-3077. Quorum-based protocol for reading and writing edit logs.

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/BPOfferService.java

@@ -396,7 +396,7 @@ class BPOfferService {
   }
 
   @VisibleForTesting
-  synchronized List<BPServiceActor> getBPServiceActors() {
+  List<BPServiceActor> getBPServiceActors() {
     return Lists.newArrayList(bpServices);
   }