HDFS-5579. Under construction files make DataNode decommission take very long hours. Contributed by zhaoyunjiong.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1557904 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -749,6 +749,9 @@ Release 2.4.0 - UNRELEASED
     HDFS-5710. FSDirectory#getFullPathName should check inodes against null.
     (Uma Maheswara Rao G via jing9)
 
+    HDFS-5579. Under construction files make DataNode decommission take very long
+    hours. (zhaoyunjiong via jing9)
+
   BREAKDOWN OF HDFS-2832 SUBTASKS AND RELATED JIRAS
 
     HDFS-4985. Add storage type to the protocol and expose it in block report

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockCollection.java

@@ -31,7 +31,7 @@ public interface BlockCollection {
   /**
    * Get the last block of the collection.
    */
-  public BlockInfo getLastBlock() throws IOException;
+  public BlockInfo getLastBlock();
 
   /** 
    * Get content summary.

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockManager.java

@@ -1214,8 +1214,10 @@ public class BlockManager {
             // block should belong to a file
             bc = blocksMap.getBlockCollection(block);
             // abandoned block or block reopened for append
-            if(bc == null || bc.isUnderConstruction()) {
+            if (bc == null
-              neededReplications.remove(block, priority); // remove from neededReplications
+                || (bc.isUnderConstruction() && block.equals(bc.getLastBlock()))) {
+              // remove from neededReplications
+              neededReplications.remove(block, priority);
               continue;
             }
 
@@ -1295,7 +1297,7 @@ public class BlockManager {
           // block should belong to a file
           bc = blocksMap.getBlockCollection(block);
           // abandoned block or block reopened for append
-          if(bc == null || bc.isUnderConstruction()) {
+          if(bc == null || (bc.isUnderConstruction() && block.equals(bc.getLastBlock()))) {
             neededReplications.remove(block, priority); // remove from neededReplications
             rw.targets = null;
             continue;
@@ -2906,8 +2908,16 @@ assert storedBlock.findDatanode(dn) < 0 : "Block " + block
         NumberReplicas num = countNodes(block);
         int curReplicas = num.liveReplicas();
         int curExpectedReplicas = getReplication(block);
+                
         if (isNeededReplication(block, curExpectedReplicas, curReplicas)) {
           if (curExpectedReplicas > curReplicas) {
+            if (bc.isUnderConstruction()) {
+              if (block.equals(bc.getLastBlock()) && curReplicas > minReplication) {
+                continue;
+              }
+              underReplicatedInOpenFiles++;
+            }
+            
             // Log info about one block for this node which needs replication
             if (!status) {
               status = true;
@@ -2924,9 +2934,6 @@ assert storedBlock.findDatanode(dn) < 0 : "Block " + block
             if ((curReplicas == 0) && (num.decommissionedReplicas() > 0)) {
               decommissionOnlyReplicas++;
             }
-            if (bc.isUnderConstruction()) {
-              underReplicatedInOpenFiles++;
-            }
           }
           if (!neededReplications.contains(block) &&
             pendingReplications.getNumReplicas(block) == 0) {

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/INodeFile.java

@@ -640,7 +640,7 @@ public class INodeFile extends INodeWithAdditionalFields
   }
 
   @Override
-  public BlockInfo getLastBlock() throws IOException {
+  public BlockInfo getLastBlock() {
     return blocks == null || blocks.length == 0? null: blocks[blocks.length-1];
   }
 

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDecommission.java

@@ -42,6 +42,7 @@ import org.apache.hadoop.hdfs.protocol.DatanodeInfo;
 import org.apache.hadoop.hdfs.protocol.DatanodeInfo.AdminStates;
 import org.apache.hadoop.hdfs.protocol.HdfsConstants.DatanodeReportType;
 import org.apache.hadoop.hdfs.protocol.LocatedBlock;
+import org.apache.hadoop.hdfs.protocol.LocatedBlocks;
 import org.apache.hadoop.hdfs.server.namenode.FSNamesystem;
 import org.apache.hadoop.hdfs.server.namenode.NameNode;
 import org.apache.hadoop.hdfs.server.namenode.NameNodeAdapter;
@@ -779,4 +780,53 @@ public class TestDecommission {
       Thread.sleep(HEARTBEAT_INTERVAL * 1000);
     }
   }
+  
+  @Test(timeout=120000)
+  public void testDecommissionWithOpenfile() throws IOException, InterruptedException {
+    LOG.info("Starting test testDecommissionWithOpenfile");
+    
+    //At most 4 nodes will be decommissioned
+    startCluster(1, 7, conf);
+        
+    FileSystem fileSys = cluster.getFileSystem(0);
+    FSNamesystem ns = cluster.getNamesystem(0);
+    
+    String openFile = "/testDecommissionWithOpenfile.dat";
+           
+    writeFile(fileSys, new Path(openFile), (short)3);   
+    // make sure the file was open for write
+    FSDataOutputStream fdos =  fileSys.append(new Path(openFile)); 
+    
+    LocatedBlocks lbs = NameNodeAdapter.getBlockLocations(cluster.getNameNode(0), openFile, 0, fileSize);
+              
+    DatanodeInfo[] dnInfos4LastBlock = lbs.getLastLocatedBlock().getLocations();
+    DatanodeInfo[] dnInfos4FirstBlock = lbs.get(0).getLocations();
+    
+    ArrayList<String> nodes = new ArrayList<String>();
+    ArrayList<DatanodeInfo> dnInfos = new ArrayList<DatanodeInfo>();
+   
+    for (DatanodeInfo datanodeInfo : dnInfos4FirstBlock) {
+      DatanodeInfo found = datanodeInfo;
+      for (DatanodeInfo dif: dnInfos4LastBlock) {
+        if (datanodeInfo.equals(dif)) {
+         found = null;         
+        }
+      }
+      if (found != null) {
+        nodes.add(found.getXferAddr());
+        dnInfos.add(found);
+      }
+    }
+    //decommission one of the 3 nodes which have last block
+    nodes.add(dnInfos4LastBlock[0].getXferAddr());
+    dnInfos.add(dnInfos4LastBlock[0]);
+    
+    writeConfigFile(excludeFile, nodes);
+    refreshNodes(ns, conf);  
+    for (DatanodeInfo dn : dnInfos) {
+      waitNodeState(dn, AdminStates.DECOMMISSIONED);
+    }           
+
+    fdos.close();
+  }
 }