private File addBlock(Block b, File src, boolean createOk, boolean resetIdx)
throws IOException {
if (numBlocks < maxBlocksPerDir) {
File dest = new File(dir, b.getBlockName());
File metaData = getMetaFile(src, b);
File newmeta = getMetaFile(dest, b);
if (!metaData.renameTo(newmeta) || !src.renameTo(dest)) {
throw new IOException(
"could not move files for " + b + " from tmp to " + dest.getAbsolutePath());
}
if (DataNode.LOG.isDebugEnabled()) {
DataNode.LOG.debug("addBlock: Moved " + metaData + " to " + newmeta);
DataNode.LOG.debug("addBlock: Moved " + src + " to " + dest);
}
numBlocks += 1;
return dest;
}
if (lastChildIdx < 0 && resetIdx) {
// reset so that all children will be checked
lastChildIdx = random.nextInt(children.length);
}
if (lastChildIdx >= 0 && children != null) {
// Check if any child-tree has room for a block.
for (int i = 0; i < children.length; i++) {
int idx = (lastChildIdx + i) % children.length;
File file = children[idx].addBlock(b, src, false, resetIdx);
if (file != null) {
lastChildIdx = idx;
return file;
}
}
lastChildIdx = -1;
}
if (!createOk) {
return null;
}
if (children == null || children.length == 0) {
children = new FSDir[maxBlocksPerDir];
for (int idx = 0; idx < maxBlocksPerDir; idx++) {
children[idx] = new FSDir(new File(dir, DataStorage.BLOCK_SUBDIR_PREFIX + idx));
}
}
// now pick a child randomly for creating a new set of subdirs.
lastChildIdx = random.nextInt(children.length);
return children[lastChildIdx].addBlock(b, src, true, false);
}
/**
* Start writing to a block file If isRecovery is true and the block pre-exists, then we kill all
* volumeMap.put(b, v); volumeMap.put(b, v); other threads that might be writing to this block,
* and then reopen the file.
*/
public BlockWriteStreams writeToBlock(Block b, boolean isRecovery) throws IOException {
//
// Make sure the block isn't a valid one - we're still creating it!
//
if (isValidBlock(b)) {
if (!isRecovery) {
throw new BlockAlreadyExistsException(
"Block " + b + " is valid, and cannot be written to.");
}
// If the block was successfully finalized because all packets
// were successfully processed at the Datanode but the ack for
// some of the packets were not received by the client. The client
// re-opens the connection and retries sending those packets.
// The other reason is that an "append" is occurring to this block.
detachBlock(b, 1);
}
long blockSize = b.getNumBytes();
//
// Serialize access to /tmp, and check if file already there.
//
File f = null;
List<Thread> threads = null;
synchronized (this) {
//
// Is it already in the create process?
//
ActiveFile activeFile = ongoingCreates.get(b);
if (activeFile != null) {
f = activeFile.file;
threads = activeFile.threads;
if (!isRecovery) {
throw new BlockAlreadyExistsException(
"Block "
+ b
+ " has already been started (though not completed), and thus cannot be created.");
} else {
for (Thread thread : threads) {
thread.interrupt();
}
}
ongoingCreates.remove(b);
}
FSVolume v = null;
if (!isRecovery) {
v = volumes.getNextVolume(blockSize);
// create temporary file to hold block in the designated volume
f = createTmpFile(v, b);
volumeMap.put(b, new DatanodeBlockInfo(v));
} else if (f != null) {
DataNode.LOG.info("Reopen already-open Block for append " + b);
// create or reuse temporary file to hold block in the
// designated volume
v = volumeMap.get(b).getVolume();
volumeMap.put(b, new DatanodeBlockInfo(v));
} else {
// reopening block for appending to it.
DataNode.LOG.info("Reopen Block for append " + b);
v = volumeMap.get(b).getVolume();
f = createTmpFile(v, b);
File blkfile = getBlockFile(b);
File oldmeta = getMetaFile(b);
File newmeta = getMetaFile(f, b);
// rename meta file to tmp directory
DataNode.LOG.debug("Renaming " + oldmeta + " to " + newmeta);
if (!oldmeta.renameTo(newmeta)) {
throw new IOException(
"Block "
+ b
+ " reopen failed. "
+ " Unable to move meta file "
+ oldmeta
+ " to tmp dir "
+ newmeta);
}
// rename block file to tmp directory
DataNode.LOG.debug("Renaming " + blkfile + " to " + f);
if (!blkfile.renameTo(f)) {
if (!f.delete()) {
throw new IOException(
"Block " + b + " reopen failed. " + " Unable to remove file " + f);
}
if (!blkfile.renameTo(f)) {
throw new IOException(
"Block "
+ b
+ " reopen failed. "
+ " Unable to move block file "
+ blkfile
+ " to tmp dir "
+ f);
}
}
volumeMap.put(b, new DatanodeBlockInfo(v));
}
if (f == null) {
DataNode.LOG.warn("Block " + b + " reopen failed " + " Unable to locate tmp file.");
throw new IOException("Block " + b + " reopen failed " + " Unable to locate tmp file.");
}
ongoingCreates.put(b, new ActiveFile(f, threads));
}
try {
if (threads != null) {
for (Thread thread : threads) {
thread.join();
}
}
} catch (InterruptedException e) {
throw new IOException("Recovery waiting for thread interrupted.");
}
//
// Finally, allow a writer to the block file
// REMIND - mjc - make this a filter stream that enforces a max
// block size, so clients can't go crazy
//
File metafile = getMetaFile(f, b);
DataNode.LOG.debug("writeTo blockfile is " + f + " of size " + f.length());
DataNode.LOG.debug("writeTo metafile is " + metafile + " of size " + metafile.length());
return createBlockWriteStreams(f, metafile);
}
/**
* Try to update an old block to a new block. If there are ongoing create threads running for the
* old block, the threads will be returned without updating the block.
*
* @return ongoing create threads if there is any. Otherwise, return null.
*/
private synchronized List<Thread> tryUpdateBlock(Block oldblock, Block newblock)
throws IOException {
// check ongoing create threads
final ActiveFile activefile = ongoingCreates.get(oldblock);
if (activefile != null && !activefile.threads.isEmpty()) {
// remove dead threads
for (Iterator<Thread> i = activefile.threads.iterator(); i.hasNext(); ) {
final Thread t = i.next();
if (!t.isAlive()) {
i.remove();
}
}
// return living threads
if (!activefile.threads.isEmpty()) {
return new ArrayList<Thread>(activefile.threads);
}
}
// No ongoing create threads is alive. Update block.
File blockFile = findBlockFile(oldblock.getBlockId());
if (blockFile == null) {
throw new IOException("Block " + oldblock + " does not exist.");
}
File oldMetaFile = findMetaFile(blockFile);
long oldgs = parseGenerationStamp(blockFile, oldMetaFile);
// rename meta file to a tmp file
File tmpMetaFile =
new File(
oldMetaFile.getParent(),
oldMetaFile.getName() + "_tmp" + newblock.getGenerationStamp());
if (!oldMetaFile.renameTo(tmpMetaFile)) {
throw new IOException("Cannot rename block meta file to " + tmpMetaFile);
}
// update generation stamp
if (oldgs > newblock.getGenerationStamp()) {
throw new IOException(
"Cannot update block (id="
+ newblock.getBlockId()
+ ") generation stamp from "
+ oldgs
+ " to "
+ newblock.getGenerationStamp());
}
// update length
if (newblock.getNumBytes() > oldblock.getNumBytes()) {
throw new IOException(
"Cannot update block file (="
+ blockFile
+ ") length from "
+ oldblock.getNumBytes()
+ " to "
+ newblock.getNumBytes());
}
if (newblock.getNumBytes() < oldblock.getNumBytes()) {
truncateBlock(blockFile, tmpMetaFile, oldblock.getNumBytes(), newblock.getNumBytes());
}
// rename the tmp file to the new meta file (with new generation stamp)
File newMetaFile = getMetaFile(blockFile, newblock);
if (!tmpMetaFile.renameTo(newMetaFile)) {
throw new IOException("Cannot rename tmp meta file to " + newMetaFile);
}
updateBlockMap(ongoingCreates, oldblock, newblock);
updateBlockMap(volumeMap, oldblock, newblock);
// paranoia! verify that the contents of the stored block
// matches the block file on disk.
validateBlockMetadata(newblock);
return null;
}
/**
* Method to move files from HDFS to local filesystem
*
* <p>localPath: Path on the machines filesystem fs:FileSystem object from HDFS pathList:List of
* paths for files that might need to be backed up size:max size in bytes to be backed up
*
* <p>ReturnsDate of the last files backed up if reached size limit, else, zero
*/
public long backupFiles(
String localPath, String preservePath, FileSystem fs, ArrayList<Path> pathList, long size) {
Path fsPath;
long tmpSize = 0;
long tmpDate = 0;
// Start iterating over all paths
for (Path hdfsPath : pathList) {
try {
long nFileSize = fs.getContentSummary(hdfsPath).getLength();
tmpSize = tmpSize + nFileSize;
if ((tmpSize <= size) || (size == 0)) {
FileStatus stat = fs.getFileStatus(hdfsPath);
System.err.println(
"File "
+ hdfsPath.toUri().getPath()
+ " "
+ nFileSize
+ " bytes, "
+ "perms: "
+ stat.getOwner()
+ "/"
+ stat.getGroup()
+ ", "
+ stat.getPermission().toString());
tmpDate = stat.getModificationTime() / 1000;
String sFsPath = localPath + hdfsPath.toUri().getPath();
fsPath = new Path(sFsPath);
File f = new File(sFsPath);
// COMMENTED OUT: until a few backup cycles run
// and the mtime gets in fact set on all copied
// files.
//
// ignore it if the file exists and has the same mtime
// if (f.exists() && f.isFile() && f.lastModified() == stat.getModificationTime())
// {
// System.out.println("no need to backup " + f.toString() + ", mtime matches hdfs");
// continue;
// }
if (false == m_bDryRun) {
// check if we need to back up the local file
// (not directory), if it already exists.
if (f.exists() && f.isFile()) {
// ignore files with substrings in the
// no-preserve file
if (true == doPreserveFile(sFsPath)) {
// move it to the backup path
String sNewPath = preservePath + hdfsPath.toUri().getPath();
File newFile = new File(sNewPath);
// create directory structure for new file?
if (false == newFile.getParentFile().exists()) {
if (false == newFile.getParentFile().mkdirs()) {
System.err.println("Failed to mkdirs " + newFile.getParentFile().toString());
System.exit(1);
}
}
// rename existing file to new location
if (false == f.renameTo(newFile)) {
System.err.println(
"Failed to renameTo " + f.toString() + " to " + newFile.toString());
System.exit(1);
}
System.out.println("preserved " + f.toString() + " into " + newFile.toString());
} else {
System.out.println("skipped preservation of " + f.toString());
}
}
// copy from hdfs to local filesystem
fs.copyToLocalFile(hdfsPath, fsPath);
// set the mtime to match hdfs file
f.setLastModified(stat.getModificationTime());
// compare checksums on both files
compareChecksums(fs, hdfsPath, sFsPath);
}
// don't print the progress after every file -- go
// by at least 1% increments
long nPercentDone = (long) (100 * tmpSize / m_nTotalBytes);
if (nPercentDone > m_nLastPercentBytesDone) {
System.out.println(
"progress: copied "
+ prettyPrintBytes(tmpSize)
+ ", "
+ nPercentDone
+ "% done"
+ ", tstamp="
+ tmpDate);
m_nLastPercentBytesDone = nPercentDone;
}
if (m_nSleepSeconds > 0) {
try {
Thread.sleep(1000 * m_nSleepSeconds);
} catch (Exception e2) {
// ignore
}
}
} else {
return tmpDate;
}
} catch (IOException e) {
System.err.println("FATAL ERROR: Something wrong with the file");
System.err.println(e);
System.out.println(tmpDate);
System.exit(1);
return 0;
}
}
return 0;
}