/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.hadoop.hdfs.server.namenode;
import java.io.BufferedInputStream;
import java.io.DataInputStream;
import java.io.EOFException;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.security.PrivilegedExceptionAction;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.hdfs.DFSConfigKeys;
import org.apache.hadoop.hdfs.protocol.HdfsConstants;
import org.apache.hadoop.hdfs.server.common.Storage;
import org.apache.hadoop.hdfs.server.namenode.TransferFsImage.HttpGetFailedException;
import org.apache.hadoop.io.IOUtils;
import org.apache.hadoop.hdfs.protocol.HdfsConstants;
import org.apache.hadoop.security.SecurityUtil;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Preconditions;
import com.google.common.base.Throwables;
/**
* An implementation of the abstract class {@link EditLogInputStream}, which
* reads edits from a file. That file may be either on the local disk or
* accessible via a URL.
*/
@InterfaceAudience.Private
public class EditLogFileInputStream extends EditLogInputStream {
private final LogSource log;
private final long firstTxId;
private final long lastTxId;
private final boolean isInProgress;
private int maxOpSize;
static private enum State {
UNINIT,
OPEN,
CLOSED
}
private State state = State.UNINIT;
private InputStream fStream = null;
private int logVersion = 0;
private FSEditLogOp.Reader reader = null;
private FSEditLogLoader.PositionTrackingInputStream tracker = null;
private DataInputStream dataIn = null;
static final Log LOG = LogFactory.getLog(EditLogInputStream.class);
/**
* Open an EditLogInputStream for the given file.
* The file is pretransactional, so has no txids
* @param name filename to open
* @throws LogHeaderCorruptException if the header is either missing or
* appears to be corrupt/truncated
* @throws IOException if an actual IO error occurs while reading the
* header
*/
EditLogFileInputStream(File name)
throws LogHeaderCorruptException, IOException {
this(name, HdfsConstants.INVALID_TXID, HdfsConstants.INVALID_TXID, false);
}
/**
* Open an EditLogInputStream for the given file.
* @param name filename to open
* @param firstTxId first transaction found in file
* @param lastTxId last transaction id found in file
* @throws LogHeaderCorruptException if the header is either missing or
* appears to be corrupt/truncated
* @throws IOException if an actual IO error occurs while reading the
* header
*/
public EditLogFileInputStream(File name, long firstTxId, long lastTxId,
boolean isInProgress) {
this(new FileLog(name), firstTxId, lastTxId, isInProgress);
}
/**
* Open an EditLogInputStream for the given URL.
*
* @param url the url hosting the log
* @param startTxId the expected starting txid
* @param endTxId the expected ending txid
* @param inProgress whether the log is in-progress
* @return a stream from which edits may be read
*/
public static EditLogInputStream fromUrl(URL url, long startTxId,
long endTxId, boolean inProgress) {
return new EditLogFileInputStream(new URLLog(url),
startTxId, endTxId, inProgress);
}
private EditLogFileInputStream(LogSource log,
long firstTxId, long lastTxId,
boolean isInProgress) {
this.log = log;
this.firstTxId = firstTxId;
this.lastTxId = lastTxId;
this.isInProgress = isInProgress;
this.maxOpSize = DFSConfigKeys.DFS_NAMENODE_MAX_OP_SIZE_DEFAULT;
}
private void init() throws LogHeaderCorruptException, IOException {
Preconditions.checkState(state == State.UNINIT);
BufferedInputStream bin = null;
try {
fStream = log.getInputStream();
bin = new BufferedInputStream(fStream);
tracker = new FSEditLogLoader.PositionTrackingInputStream(bin);
dataIn = new DataInputStream(tracker);
try {
logVersion = readLogVersion(dataIn);
} catch (EOFException eofe) {
throw new LogHeaderCorruptException("No header found in log");
}
reader = new FSEditLogOp.Reader(dataIn, tracker, logVersion);
reader.setMaxOpSize(maxOpSize);
state = State.OPEN;
} finally {
if (reader == null) {
IOUtils.cleanup(LOG, dataIn, tracker, bin, fStream);
state = State.CLOSED;
}
}
}
@Override
public long getFirstTxId() {
return firstTxId;
}
@Override
public long getLastTxId() {
return lastTxId;
}
@Override
public String getName() {
return log.getName();
}
private FSEditLogOp nextOpImpl(boolean skipBrokenEdits) throws IOException {
FSEditLogOp op = null;
switch (state) {
case UNINIT:
try {
init();
} catch (Throwable e) {
LOG.error("caught exception initializing " + this, e);
if (skipBrokenEdits) {
return null;
}
Throwables.propagateIfPossible(e, IOException.class);
}
Preconditions.checkState(state != State.UNINIT);
return nextOpImpl(skipBrokenEdits);
case OPEN:
op = reader.readOp(skipBrokenEdits);
if ((op != null) && (op.hasTransactionId())) {
long txId = op.getTransactionId();
if ((txId >= lastTxId) &&
(lastTxId != HdfsConstants.INVALID_TXID)) {
//
// Sometimes, the NameNode crashes while it's writing to the
// edit log. In that case, you can end up with an unfinalized edit log
// which has some garbage at the end.
// JournalManager#recoverUnfinalizedSegments will finalize these
// unfinished edit logs, giving them a defined final transaction
// ID. Then they will be renamed, so that any subsequent
// readers will have this information.
//
// Since there may be garbage at the end of these "cleaned up"
// logs, we want to be sure to skip it here if we've read everything
// we were supposed to read out of the stream.
// So we force an EOF on all subsequent reads.
//
long skipAmt = log.length() - tracker.getPos();
if (skipAmt > 0) {
if (LOG.isDebugEnabled()) {
LOG.debug("skipping " + skipAmt + " bytes at the end " +
"of edit log '" + getName() + "': reached txid " + txId +
" out of " + lastTxId);
}
tracker.clearLimit();
IOUtils.skipFully(tracker, skipAmt);
}
}
}
break;
case CLOSED:
break; // return null
}
return op;
}
@Override
protected FSEditLogOp nextOp() throws IOException {
return nextOpImpl(false);
}
@Override
protected FSEditLogOp nextValidOp() {
try {
return nextOpImpl(true);
} catch (Throwable e) {
LOG.error("nextValidOp: got exception while reading " + this, e);
return null;
}
}
@Override
public int getVersion() throws IOException {
if (state == State.UNINIT) {
init();
}
return logVersion;
}
@Override
public long getPosition() {
if (state == State.OPEN) {
return tracker.getPos();
} else {
return 0;
}
}
@Override
public void close() throws IOException {
if (state == State.OPEN) {
dataIn.close();
}
state = State.CLOSED;
}
@Override
public long length() throws IOException {
// file size + size of both buffers
return log.length();
}
@Override
public boolean isInProgress() {
return isInProgress;
}
@Override
public String toString() {
return getName();
}
static FSEditLogLoader.EditLogValidation validateEditLog(File file) throws IOException {
EditLogFileInputStream in;
try {
in = new EditLogFileInputStream(file);
in.getVersion(); // causes us to read the header
} catch (LogHeaderCorruptException e) {
// If the header is malformed or the wrong value, this indicates a corruption
LOG.warn("Log file " + file + " has no valid header", e);
return new FSEditLogLoader.EditLogValidation(0,
HdfsConstants.INVALID_TXID, true);
}
try {
return FSEditLogLoader.validateEditLog(in);
} finally {
IOUtils.closeStream(in);
}
}
/**
* Read the header of fsedit log
* @param in fsedit stream
* @return the edit log version number
* @throws IOException if error occurs
*/
@VisibleForTesting
static int readLogVersion(DataInputStream in)
throws IOException, LogHeaderCorruptException {
int logVersion;
try {
logVersion = in.readInt();
} catch (EOFException eofe) {
throw new LogHeaderCorruptException(
"Reached EOF when reading log header");
}
if (logVersion < HdfsConstants.LAYOUT_VERSION || // future version
logVersion > Storage.LAST_UPGRADABLE_LAYOUT_VERSION) { // unsupported
throw new LogHeaderCorruptException(
"Unexpected version of the file system log file: "
+ logVersion + ". Current version = "
+ HdfsConstants.LAYOUT_VERSION + ".");
}
return logVersion;
}
/**
* Exception indicating that the header of an edits log file is
* corrupted. This can be because the header is not present,
* or because the header data is invalid (eg claims to be
* over a newer version than the running NameNode)
*/
static class LogHeaderCorruptException extends IOException {
private static final long serialVersionUID = 1L;
private LogHeaderCorruptException(String msg) {
super(msg);
}
}
private interface LogSource {
public InputStream getInputStream() throws IOException;
public long length();
public String getName();
}
private static class FileLog implements LogSource {
private final File file;
public FileLog(File file) {
this.file = file;
}
@Override
public InputStream getInputStream() throws IOException {
return new FileInputStream(file);
}
@Override
public long length() {
return file.length();
}
@Override
public String getName() {
return file.getPath();
}
}
private static class URLLog implements LogSource {
private final URL url;
private long advertisedSize = -1;
private final static String CONTENT_LENGTH = "Content-Length";
public URLLog(URL url) {
this.url = url;
}
@Override
public InputStream getInputStream() throws IOException {
return SecurityUtil.doAsCurrentUser(
new PrivilegedExceptionAction<InputStream>() {
@Override
public InputStream run() throws IOException {
HttpURLConnection connection = (HttpURLConnection)
SecurityUtil.openSecureHttpConnection(url);
if (connection.getResponseCode() != HttpURLConnection.HTTP_OK) {
throw new HttpGetFailedException(
"Fetch of " + url +
" failed with status code " + connection.getResponseCode() +
"\nResponse message:\n" + connection.getResponseMessage(),
connection);
}
String contentLength = connection.getHeaderField(CONTENT_LENGTH);
if (contentLength != null) {
advertisedSize = Long.parseLong(contentLength);
if (advertisedSize <= 0) {
throw new IOException("Invalid " + CONTENT_LENGTH + " header: " +
contentLength);
}
} else {
throw new IOException(CONTENT_LENGTH + " header is not provided " +
"by the server when trying to fetch " + url);
}
return connection.getInputStream();
}
});
}
@Override
public long length() {
return advertisedSize;
}
@Override
public String getName() {
return url.toString();
}
}
@Override
public void setMaxOpSize(int maxOpSize) {
this.maxOpSize = maxOpSize;
if (reader != null) {
reader.setMaxOpSize(maxOpSize);
}
}
}