public void testCorruptBlock() throws Exception {
Configuration conf = new HdfsConfiguration();
conf.setLong(DFSConfigKeys.DFS_BLOCKREPORT_INTERVAL_MSEC_KEY, 1000);
FileSystem fs = null;
DFSClient dfsClient = null;
LocatedBlocks blocks = null;
int replicaCount = 0;
Random random = new Random();
String outStr = null;
short factor = 1;
MiniDFSCluster cluster = null;
try {
cluster = new MiniDFSCluster.Builder(conf).numDataNodes(1).build();
cluster.waitActive();
fs = cluster.getFileSystem();
Path file1 = new Path("/testCorruptBlock");
DFSTestUtil.createFile(fs, file1, 1024, factor, 0);
// Wait until file replication has completed
DFSTestUtil.waitReplication(fs, file1, factor);
ExtendedBlock block = DFSTestUtil.getFirstBlock(fs, file1);
// Make sure filesystem is in healthy state
outStr = runFsck(conf, 0, true, "/");
System.out.println(outStr);
assertTrue(outStr.contains(NamenodeFsck.HEALTHY_STATUS));
// corrupt replicas
File blockFile = MiniDFSCluster.getBlockFile(0, block);
if (blockFile != null && blockFile.exists()) {
RandomAccessFile raFile = new RandomAccessFile(blockFile, "rw");
FileChannel channel = raFile.getChannel();
String badString = "BADBAD";
int rand = random.nextInt((int) channel.size()/2);
raFile.seek(rand);
raFile.write(badString.getBytes());
raFile.close();
}
// Read the file to trigger reportBadBlocks
try {
IOUtils.copyBytes(fs.open(file1), new IOUtils.NullOutputStream(), conf,
true);
} catch (IOException ie) {
// Ignore exception
}
dfsClient = new DFSClient(new InetSocketAddress("localhost",
cluster.getNameNodePort()), conf);
blocks = dfsClient.getNamenode().
getBlockLocations(file1.toString(), 0, Long.MAX_VALUE);
replicaCount = blocks.get(0).getLocations().length;
while (replicaCount != factor) {
try {
Thread.sleep(100);
} catch (InterruptedException ignore) {
}
blocks = dfsClient.getNamenode().
getBlockLocations(file1.toString(), 0, Long.MAX_VALUE);
replicaCount = blocks.get(0).getLocations().length;
}
assertTrue (blocks.get(0).isCorrupt());
// Check if fsck reports the same
outStr = runFsck(conf, 1, true, "/");
System.out.println(outStr);
assertTrue(outStr.contains(NamenodeFsck.CORRUPT_STATUS));