HDFS-8117. More accurate verification in SimulatedFSDataset: replace DEFAULT_DATABYTE with patterned data. Contributed by Zhe Zhang.

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

@@ -113,6 +113,9 @@ Release 2.8.0 - UNRELEASED
     HDFS-8083. Move dfs.client.write.* conf from DFSConfigKeys to 
     HdfsClientConfigKeys.Write.  (szetszwo)
 
+    HDFS-8117. More accurate verification in SimulatedFSDataset: replace
+    DEFAULT_DATABYTE with patterned data. (Zhe Zhang via wang)
+
   OPTIMIZATIONS
 
     HDFS-8026. Trace FSOutputSummer#writeChecksumChunks rather than

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

@@ -91,6 +91,7 @@ import org.apache.hadoop.fs.permission.FsPermission;
 import org.apache.hadoop.hdfs.MiniDFSCluster.NameNodeInfo;
 import org.apache.hadoop.hdfs.client.HdfsClientConfigKeys;
 import org.apache.hadoop.hdfs.client.HdfsDataInputStream;
+import org.apache.hadoop.hdfs.protocol.Block;
 import org.apache.hadoop.hdfs.protocol.CacheDirectiveInfo;
 import org.apache.hadoop.hdfs.protocol.CachePoolInfo;
 import org.apache.hadoop.hdfs.protocol.DatanodeID;
@@ -117,6 +118,7 @@ import org.apache.hadoop.hdfs.server.common.HdfsServerConstants.StartupOption;
 import org.apache.hadoop.hdfs.server.common.StorageInfo;
 import org.apache.hadoop.hdfs.server.datanode.DataNode;
 import org.apache.hadoop.hdfs.server.datanode.DataNodeLayoutVersion;
+import org.apache.hadoop.hdfs.server.datanode.SimulatedFSDataset;
 import org.apache.hadoop.hdfs.server.datanode.TestTransferRbw;
 import org.apache.hadoop.hdfs.server.datanode.fsdataset.FsDatasetSpi;
 import org.apache.hadoop.hdfs.server.namenode.FSEditLog;
@@ -1776,4 +1778,27 @@ public class DFSTestUtil {
     dn.setLastUpdate(Time.now() + offset);
     dn.setLastUpdateMonotonic(Time.monotonicNow() + offset);
   }
+
+  /**
+   * This method takes a set of block locations and fills the provided buffer
+   * with expected bytes based on simulated content from
+   * {@link SimulatedFSDataset}.
+   *
+   * @param lbs The block locations of a file
+   * @param expected The buffer to be filled with expected bytes on the above
+   *                 locations.
+   */
+  public static void fillExpectedBuf(LocatedBlocks lbs, byte[] expected) {
+    Block[] blks = new Block[lbs.getLocatedBlocks().size()];
+    for (int i = 0; i < lbs.getLocatedBlocks().size(); i++) {
+      blks[i] = lbs.getLocatedBlocks().get(i).getBlock().getLocalBlock();
+    }
+    int bufPos = 0;
+    for (Block b : blks) {
+      for (long blkPos = 0; blkPos < b.getNumBytes(); blkPos++) {
+        assert bufPos < expected.length;
+        expected[bufPos++] = SimulatedFSDataset.simulatedByte(b, blkPos);
+      }
+    }
+  }
 }

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

@@ -68,7 +68,7 @@ public class TestFileAppend{
   //
   // verify that the data written to the full blocks are sane
   // 
-  private void checkFile(FileSystem fileSys, Path name, int repl)
+  private void checkFile(DistributedFileSystem fileSys, Path name, int repl)
     throws IOException {
     boolean done = false;
 
@@ -96,9 +96,9 @@ public class TestFileAppend{
     byte[] expected = 
         new byte[AppendTestUtil.NUM_BLOCKS * AppendTestUtil.BLOCK_SIZE];
     if (simulatedStorage) {
-      for (int i= 0; i < expected.length; i++) {  
-        expected[i] = SimulatedFSDataset.DEFAULT_DATABYTE;
-      }
+      LocatedBlocks lbs = fileSys.getClient().getLocatedBlocks(name.toString(),
+          0, AppendTestUtil.FILE_SIZE);
+      DFSTestUtil.fillExpectedBuf(lbs, expected);
     } else {
       System.arraycopy(fileContents, 0, expected, 0, expected.length);
     }
@@ -193,7 +193,7 @@ public class TestFileAppend{
     }
     fileContents = AppendTestUtil.initBuffer(AppendTestUtil.FILE_SIZE);
     MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf).build();
-    FileSystem fs = cluster.getFileSystem();
+    DistributedFileSystem fs = cluster.getFileSystem();
     try {
 
       // create a new file.
@@ -249,7 +249,7 @@ public class TestFileAppend{
     }
     fileContents = AppendTestUtil.initBuffer(AppendTestUtil.FILE_SIZE);
     MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf).build();
-    FileSystem fs = cluster.getFileSystem();
+    DistributedFileSystem fs = cluster.getFileSystem();
     try {
 
       // create a new file.

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

@@ -38,6 +38,7 @@ import org.apache.hadoop.fs.FSDataOutputStream;
 import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.hdfs.client.HdfsClientConfigKeys;
+import org.apache.hadoop.hdfs.protocol.LocatedBlocks;
 import org.apache.hadoop.hdfs.protocol.datatransfer.DataTransferProtocol;
 import org.apache.hadoop.hdfs.server.datanode.SimulatedFSDataset;
 import org.apache.hadoop.io.IOUtils;
@@ -55,6 +56,8 @@ import org.mockito.stubbing.Answer;
 public class TestPread {
   static final long seed = 0xDEADBEEFL;
   static final int blockSize = 4096;
+  static final int numBlocksPerFile = 12;
+  static final int fileSize = numBlocksPerFile * blockSize;
   boolean simulatedStorage;
   boolean isHedgedRead;
 
@@ -72,7 +75,7 @@ public class TestPread {
     // test empty file open and read
     stm.close();
     FSDataInputStream in = fileSys.open(name);
-    byte[] buffer = new byte[12 * blockSize];
+    byte[] buffer = new byte[fileSize];
     in.readFully(0, buffer, 0, 0);
     IOException res = null;
     try { // read beyond the end of the file
@@ -87,7 +90,7 @@ public class TestPread {
       assertTrue("Cannot delete file", false);
     
     // now create the real file
-    DFSTestUtil.createFile(fileSys, name, 12 * blockSize, 12 * blockSize,
+    DFSTestUtil.createFile(fileSys, name, fileSize, fileSize,
         blockSize, (short) replication, seed);
   }
   
@@ -131,11 +134,13 @@ public class TestPread {
   
   private void pReadFile(FileSystem fileSys, Path name) throws IOException {
     FSDataInputStream stm = fileSys.open(name);
-    byte[] expected = new byte[12 * blockSize];
+    byte[] expected = new byte[fileSize];
     if (simulatedStorage) {
-      for (int i= 0; i < expected.length; i++) {  
-        expected[i] = SimulatedFSDataset.DEFAULT_DATABYTE;
-      }
+      assert fileSys instanceof DistributedFileSystem;
+      DistributedFileSystem dfs = (DistributedFileSystem) fileSys;
+      LocatedBlocks lbs = dfs.getClient().getLocatedBlocks(name.toString(),
+          0, fileSize);
+      DFSTestUtil.fillExpectedBuf(lbs, expected);
     } else {
       Random rand = new Random(seed);
       rand.nextBytes(expected);
@@ -450,7 +455,7 @@ public class TestPread {
     FileSystem fileSys = cluster.getFileSystem();
     fileSys.setVerifyChecksum(verifyChecksum);
     try {
-      Path file1 = new Path("preadtest.dat");
+      Path file1 = new Path("/preadtest.dat");
       writeFile(fileSys, file1);
       pReadFile(fileSys, file1);
       datanodeRestartTest(cluster, fileSys, file1);

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

@@ -30,6 +30,7 @@ import org.apache.hadoop.fs.FSDataInputStream;
 import org.apache.hadoop.fs.FSDataOutputStream;
 import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.hdfs.protocol.LocatedBlocks;
 import org.apache.hadoop.hdfs.server.datanode.SimulatedFSDataset;
 import org.junit.Test;
 
@@ -64,16 +65,17 @@ public class TestSmallBlock {
     }
   }
   
-  private void checkFile(FileSystem fileSys, Path name) throws IOException {
+  private void checkFile(DistributedFileSystem fileSys, Path name)
+      throws IOException {
     BlockLocation[] locations = fileSys.getFileBlockLocations(
         fileSys.getFileStatus(name), 0, fileSize);
     assertEquals("Number of blocks", fileSize, locations.length);
     FSDataInputStream stm = fileSys.open(name);
     byte[] expected = new byte[fileSize];
     if (simulatedStorage) {
-      for (int i = 0; i < expected.length; ++i) {  
-        expected[i] = SimulatedFSDataset.DEFAULT_DATABYTE;
-      }
+      LocatedBlocks lbs = fileSys.getClient().getLocatedBlocks(name.toString(),
+          0, fileSize);
+      DFSTestUtil.fillExpectedBuf(lbs, expected);
     } else {
       Random rand = new Random(seed);
       rand.nextBytes(expected);
@@ -102,9 +104,9 @@ public class TestSmallBlock {
     }
     conf.set(DFSConfigKeys.DFS_BYTES_PER_CHECKSUM_KEY, "1");
     MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf).build();
-    FileSystem fileSys = cluster.getFileSystem();
+    DistributedFileSystem fileSys = cluster.getFileSystem();
     try {
-      Path file1 = new Path("smallblocktest.dat");
+      Path file1 = new Path("/smallblocktest.dat");
       writeFile(fileSys, file1);
       checkFile(fileSys, file1);
       cleanupFile(fileSys, file1);

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/SimulatedFSDataset.java

@@ -97,12 +97,16 @@ public class SimulatedFSDataset implements FsDatasetSpi<FsVolumeSpi> {
     conf.set(DFSConfigKeys.DFS_DATANODE_FSDATASET_FACTORY_KEY,
         Factory.class.getName());
   }
+
+  public static byte simulatedByte(Block b, long offsetInBlk) {
+    byte firstByte = (byte) (b.getBlockId() % Byte.MAX_VALUE);
+    return (byte) ((firstByte + offsetInBlk) % Byte.MAX_VALUE);
+  }
   
   public static final String CONFIG_PROPERTY_CAPACITY =
       "dfs.datanode.simulateddatastorage.capacity";
   
   public static final long DEFAULT_CAPACITY = 2L<<40; // 1 terabyte
-  public static final byte DEFAULT_DATABYTE = 9;
   
   public static final String CONFIG_PROPERTY_STATE =
       "dfs.datanode.simulateddatastorage.state";
@@ -182,9 +186,9 @@ public class SimulatedFSDataset implements FsDatasetSpi<FsVolumeSpi> {
     synchronized SimulatedInputStream getIStream() {
       if (!finalized) {
         // throw new IOException("Trying to read an unfinalized block");
-         return new SimulatedInputStream(oStream.getLength(), DEFAULT_DATABYTE);
+         return new SimulatedInputStream(oStream.getLength(), theBlock);
       } else {
-        return new SimulatedInputStream(theBlock.getNumBytes(), DEFAULT_DATABYTE);
+        return new SimulatedInputStream(theBlock.getNumBytes(), theBlock);
       }
     }
     
@@ -991,21 +995,19 @@ public class SimulatedFSDataset implements FsDatasetSpi<FsVolumeSpi> {
    *
    */
   static private class SimulatedInputStream extends java.io.InputStream {
-    
-
-    byte theRepeatedData = 7;
     final long length; // bytes
     int currentPos = 0;
     byte[] data = null;
+    Block theBlock = null;
     
     /**
      * An input stream of size l with repeated bytes
      * @param l size of the stream
      * @param iRepeatedData byte that is repeated in the stream
      */
-    SimulatedInputStream(long l, byte iRepeatedData) {
+    SimulatedInputStream(long l, Block b) {
       length = l;
-      theRepeatedData = iRepeatedData;
+      theBlock = b;
     }
     
     /**
@@ -1031,8 +1033,7 @@ public class SimulatedFSDataset implements FsDatasetSpi<FsVolumeSpi> {
       if (data !=null) {
         return data[currentPos++];
       } else {
-        currentPos++;
-        return theRepeatedData;
+        return simulatedByte(theBlock, currentPos++);
       }
     }
     
@@ -1052,8 +1053,8 @@ public class SimulatedFSDataset implements FsDatasetSpi<FsVolumeSpi> {
       if (data != null) {
         System.arraycopy(data, currentPos, b, 0, bytesRead);
       } else { // all data is zero
-        for (int i : b) {  
-          b[i] = theRepeatedData;
+        for (int i = 0; i < bytesRead; i++) {
+          b[i] = simulatedByte(theBlock, currentPos + i);
         }
       }
       currentPos += bytesRead;

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/TestSimulatedFSDataset.java

@@ -144,7 +144,8 @@ public class TestSimulatedFSDataset {
     long lengthRead = 0;
     int data;
     while ((data = input.read()) != -1) {
-      assertEquals(SimulatedFSDataset.DEFAULT_DATABYTE, data);
+      assertEquals(SimulatedFSDataset.simulatedByte(b.getLocalBlock(),
+          lengthRead), data);
       lengthRead++;
     }
     assertEquals(expectedLen, lengthRead);