diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/DatanodeManager.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/DatanodeManager.java index c9365206daf..9fe9ace081d 100644 --- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/DatanodeManager.java +++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/DatanodeManager.java @@ -1172,6 +1172,7 @@ public void registerDatanode(DatanodeRegistration nodeReg) DatanodeDescriptor nodeN = host2DatanodeMap.getDatanodeByXferAddr( nodeReg.getIpAddr(), nodeReg.getXferPort()); + // Non-change. REMOVE. Number 2 if (nodeN != null && nodeN != nodeS) { NameNode.LOG.info("BLOCK* registerDatanode: " + nodeN); // nodeN previously served a different data storage, @@ -1193,14 +1194,14 @@ public void registerDatanode(DatanodeRegistration nodeReg) } } else { // nodeS is found - /* The registering datanode is a replacement node for the existing + /* The registering datanode is a replacement node for the existing data storage, which from now on will be served by a new node. If this message repeats, both nodes might have same storageID by (insanely rare) random chance. User needs to restart one of the nodes with its data cleared (or user can just remove the StorageID value in "VERSION" file under the data directory of the datanode, but this is might not work if VERSION file format has changed - */ + */ NameNode.stateChangeLog.info("BLOCK* registerDatanode: " + nodeS + " is replaced by " + nodeReg + " with the same storageID " + nodeReg.getDatanodeUuid());