/**
* Get blocks in the specified range. Includes only the complete blocks. Fetch them from the
* namenode if not cached.
*/
private synchronized List<LocatedBlock> getFinalizedBlockRange(long offset, long length)
throws IOException {
assert (locatedBlocks != null) : "locatedBlocks is null";
List<LocatedBlock> blockRange = new ArrayList<LocatedBlock>();
// search cached blocks first
int blockIdx = locatedBlocks.findBlock(offset);
if (blockIdx < 0) { // block is not cached
blockIdx = LocatedBlocks.getInsertIndex(blockIdx);
}
long remaining = length;
long curOff = offset;
while (remaining > 0) {
LocatedBlock blk = null;
if (blockIdx < locatedBlocks.locatedBlockCount()) blk = locatedBlocks.get(blockIdx);
if (blk == null || curOff < blk.getStartOffset()) {
LocatedBlocks newBlocks;
newBlocks = DFSClient.callGetBlockLocations(dfsClient.namenode, src, curOff, remaining);
locatedBlocks.insertRange(blockIdx, newBlocks.getLocatedBlocks());
continue;
}
assert curOff >= blk.getStartOffset() : "Block not found";
blockRange.add(blk);
long bytesRead = blk.getStartOffset() + blk.getBlockSize() - curOff;
remaining -= bytesRead;
curOff += bytesRead;
blockIdx++;
}
return blockRange;
}
/**
* TC11: Racing rename
*
* @throws IOException an exception might be thrown
*/
public void testTC11() throws Exception {
final Path p = new Path("/TC11/foo");
System.out.println("p=" + p);
// a. Create file and write one block of data. Close file.
final int len1 = (int) BLOCK_SIZE;
{
FSDataOutputStream out = fs.create(p, false, buffersize, REPLICATION, BLOCK_SIZE);
AppendTestUtil.write(out, 0, len1);
out.close();
}
// b. Reopen file in "append" mode. Append half block of data.
FSDataOutputStream out = fs.append(p);
final int len2 = (int) BLOCK_SIZE / 2;
AppendTestUtil.write(out, len1, len2);
out.hflush();
// c. Rename file to file.new.
final Path pnew = new Path(p + ".new");
assertTrue(fs.rename(p, pnew));
// d. Close file handle that was opened in (b).
try {
out.close();
fail("close() should throw an exception");
} catch (Exception e) {
AppendTestUtil.LOG.info("GOOD!", e);
}
// wait for the lease recovery
cluster.setLeasePeriod(1000, 1000);
AppendTestUtil.sleep(5000);
// check block sizes
final long len = fs.getFileStatus(pnew).getLen();
final LocatedBlocks locatedblocks =
fs.dfs.getNamenode().getBlockLocations(pnew.toString(), 0L, len);
final int numblock = locatedblocks.locatedBlockCount();
for (int i = 0; i < numblock; i++) {
final LocatedBlock lb = locatedblocks.get(i);
final Block blk = lb.getBlock();
final long size = lb.getBlockSize();
if (i < numblock - 1) {
assertEquals(BLOCK_SIZE, size);
}
for (DatanodeInfo datanodeinfo : lb.getLocations()) {
final DataNode dn = cluster.getDataNode(datanodeinfo.getIpcPort());
final Block metainfo = dn.data.getStoredBlock(blk.getBlockId());
assertEquals(size, metainfo.getNumBytes());
}
}
}
private BlockInfo createBlockInfo(Path file, LocatedBlock b) {
DatanodeInfo[] locations = b.getLocations();
String[] hosts = new String[locations.length];
String[] names = new String[locations.length];
for (int i = 0; i < locations.length; ++i) {
DatanodeInfo d = locations[i];
hosts[i] = d.getHost();
names[i] = d.getName();
}
BlockLocation loc = new BlockLocation(names, hosts, b.getStartOffset(), b.getBlockSize());
return new BlockInfo(loc, file);
}
/**
* Read bytes starting from the specified position.
*
* @param position start read from this position
* @param buffer read buffer
* @param offset offset into buffer
* @param length number of bytes to read
* @return actual number of bytes read
*/
@Override
public int read(long position, byte[] buffer, int offset, int length) throws IOException {
// sanity checks
dfsClient.checkOpen();
if (closed) {
throw new IOException("Stream closed");
}
failures = 0;
long filelen = getFileLength();
if ((position < 0) || (position >= filelen)) {
return -1;
}
int realLen = length;
if ((position + length) > filelen) {
realLen = (int) (filelen - position);
}
// determine the block and byte range within the block
// corresponding to position and realLen
List<LocatedBlock> blockRange = getBlockRange(position, realLen);
int remaining = realLen;
Map<ExtendedBlock, Set<DatanodeInfo>> corruptedBlockMap =
new HashMap<ExtendedBlock, Set<DatanodeInfo>>();
for (LocatedBlock blk : blockRange) {
long targetStart = position - blk.getStartOffset();
long bytesToRead = Math.min(remaining, blk.getBlockSize() - targetStart);
try {
fetchBlockByteRange(
blk, targetStart, targetStart + bytesToRead - 1, buffer, offset, corruptedBlockMap);
} finally {
// Check and report if any block replicas are corrupted.
// BlockMissingException may be caught if all block replicas are
// corrupted.
reportCheckSumFailure(corruptedBlockMap, blk.getLocations().length);
}
remaining -= bytesToRead;
position += bytesToRead;
offset += bytesToRead;
}
assert remaining == 0 : "Wrong number of bytes read.";
if (dfsClient.stats != null) {
dfsClient.stats.incrementBytesRead(realLen);
}
return realLen;
}
/**
* TC7: Corrupted replicas are present.
*
* @throws IOException an exception might be thrown
*/
public void testTC7() throws Exception {
final short repl = 2;
final Path p = new Path("/TC7/foo");
System.out.println("p=" + p);
// a. Create file with replication factor of 2. Write half block of data. Close file.
final int len1 = (int) (BLOCK_SIZE / 2);
{
FSDataOutputStream out = fs.create(p, false, buffersize, repl, BLOCK_SIZE);
AppendTestUtil.write(out, 0, len1);
out.close();
}
DFSTestUtil.waitReplication(fs, p, repl);
// b. Log into one datanode that has one replica of this block.
// Find the block file on this datanode and truncate it to zero size.
final LocatedBlocks locatedblocks =
fs.dfs.getNamenode().getBlockLocations(p.toString(), 0L, len1);
assertEquals(1, locatedblocks.locatedBlockCount());
final LocatedBlock lb = locatedblocks.get(0);
final Block blk = lb.getBlock();
assertEquals(len1, lb.getBlockSize());
DatanodeInfo[] datanodeinfos = lb.getLocations();
assertEquals(repl, datanodeinfos.length);
final DataNode dn = cluster.getDataNode(datanodeinfos[0].getIpcPort());
final FSDataset data = (FSDataset) dn.getFSDataset();
final RandomAccessFile raf = new RandomAccessFile(data.getBlockFile(blk), "rw");
AppendTestUtil.LOG.info("dn=" + dn + ", blk=" + blk + " (length=" + blk.getNumBytes() + ")");
assertEquals(len1, raf.length());
raf.setLength(0);
raf.close();
// c. Open file in "append mode". Append a new block worth of data. Close file.
final int len2 = (int) BLOCK_SIZE;
{
FSDataOutputStream out = fs.append(p);
AppendTestUtil.write(out, len1, len2);
out.close();
}
// d. Reopen file and read two blocks worth of data.
AppendTestUtil.check(fs, p, len1 + len2);
}
/**
* Get block at the specified position. Fetch it from the namenode if not cached.
*
* @param offset
* @param updatePosition whether to update current position
* @return located block
* @throws IOException
*/
private synchronized LocatedBlock getBlockAt(long offset, boolean updatePosition)
throws IOException {
assert (locatedBlocks != null) : "locatedBlocks is null";
final LocatedBlock blk;
// check offset
if (offset < 0 || offset >= getFileLength()) {
throw new IOException(
"offset < 0 || offset > getFileLength(), offset="
+ offset
+ ", updatePosition="
+ updatePosition
+ ", locatedBlocks="
+ locatedBlocks);
} else if (offset >= locatedBlocks.getFileLength()) {
// offset to the portion of the last block,
// which is not known to the name-node yet;
// getting the last block
blk = locatedBlocks.getLastLocatedBlock();
} else {
// search cached blocks first
int targetBlockIdx = locatedBlocks.findBlock(offset);
if (targetBlockIdx < 0) { // block is not cached
targetBlockIdx = LocatedBlocks.getInsertIndex(targetBlockIdx);
// fetch more blocks
LocatedBlocks newBlocks;
newBlocks = DFSClient.callGetBlockLocations(dfsClient.namenode, src, offset, prefetchSize);
assert (newBlocks != null) : "Could not find target position " + offset;
locatedBlocks.insertRange(targetBlockIdx, newBlocks.getLocatedBlocks());
}
blk = locatedBlocks.get(targetBlockIdx);
}
// update current position
if (updatePosition) {
pos = offset;
blockEnd = blk.getStartOffset() + blk.getBlockSize() - 1;
currentLocatedBlock = blk;
}
return blk;
}
/** removes a block from the har part file */
private void removeHarParityBlock(int block) throws IOException {
Path harPath = new Path(RAID_PATH, HAR_NAME);
FileStatus[] listPaths = dfs.listStatus(harPath);
boolean deleted = false;
for (FileStatus f : listPaths) {
if (f.getPath().getName().startsWith("part-")) {
final Path partPath = new Path(f.getPath().toUri().getPath());
final LocatedBlocks partBlocks =
dfs.getClient().namenode.getBlockLocations(partPath.toString(), 0, f.getLen());
if (partBlocks.locatedBlockCount() <= block) {
throw new IOException("invalid har block " + block);
}
final LocatedBlock partBlock = partBlocks.get(block);
removeAndReportBlock(dfs, partPath, partBlock);
LOG.info(
"removed block "
+ block
+ "/"
+ partBlocks.locatedBlockCount()
+ " of file "
+ partPath.toString()
+ " block size "
+ partBlock.getBlockSize());
deleted = true;
break;
}
}
if (!deleted) {
throw new IOException("cannot find part file in " + harPath.toString());
}
}
