org.apache.hadoop.net.NetUtils Maven / Gradle / Ivy
The newest version!
/**
* 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.net;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.Socket;
import java.net.SocketAddress;
import java.net.URI;
import java.net.UnknownHostException;
import java.net.ConnectException;
import java.nio.channels.SocketChannel;
import java.util.Map.Entry;
import java.util.regex.Pattern;
import java.util.*;
import javax.net.SocketFactory;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.ipc.Server;
import org.apache.hadoop.ipc.VersionedProtocol;
import org.apache.hadoop.util.ReflectionUtils;
@InterfaceAudience.LimitedPrivate({"HDFS", "MapReduce"})
@InterfaceStability.Unstable
public class NetUtils {
private static final Log LOG = LogFactory.getLog(NetUtils.class);
private static Map hostToResolved =
new HashMap();
/**
* Get the socket factory for the given class according to its
* configuration parameter
* hadoop.rpc.socket.factory.class.<ClassName>. When no
* such parameter exists then fall back on the default socket factory as
* configured by hadoop.rpc.socket.factory.class.default. If
* this default socket factory is not configured, then fall back on the JVM
* default socket factory.
*
* @param conf the configuration
* @param clazz the class (usually a {@link VersionedProtocol})
* @return a socket factory
*/
public static SocketFactory getSocketFactory(Configuration conf,
Class clazz) {
SocketFactory factory = null;
String propValue =
conf.get("hadoop.rpc.socket.factory.class." + clazz.getSimpleName());
if ((propValue != null) && (propValue.length() > 0))
factory = getSocketFactoryFromProperty(conf, propValue);
if (factory == null)
factory = getDefaultSocketFactory(conf);
return factory;
}
/**
* Get the default socket factory as specified by the configuration
* parameter hadoop.rpc.socket.factory.default
*
* @param conf the configuration
* @return the default socket factory as specified in the configuration or
* the JVM default socket factory if the configuration does not
* contain a default socket factory property.
*/
public static SocketFactory getDefaultSocketFactory(Configuration conf) {
String propValue = conf.get("hadoop.rpc.socket.factory.class.default");
if ((propValue == null) || (propValue.length() == 0))
return SocketFactory.getDefault();
return getSocketFactoryFromProperty(conf, propValue);
}
/**
* Get the socket factory corresponding to the given proxy URI. If the
* given proxy URI corresponds to an absence of configuration parameter,
* returns null. If the URI is malformed raises an exception.
*
* @param propValue the property which is the class name of the
* SocketFactory to instantiate; assumed non null and non empty.
* @return a socket factory as defined in the property value.
*/
public static SocketFactory getSocketFactoryFromProperty(
Configuration conf, String propValue) {
try {
Class theClass = conf.getClassByName(propValue);
return (SocketFactory) ReflectionUtils.newInstance(theClass, conf);
} catch (ClassNotFoundException cnfe) {
throw new RuntimeException("Socket Factory class not found: " + cnfe);
}
}
/**
* Util method to build socket addr from either:
* :
* ://:/
*/
public static InetSocketAddress createSocketAddr(String target) {
return createSocketAddr(target, -1);
}
/**
* Util method to build socket addr from either:
*
* :
* ://:/
*/
public static InetSocketAddress createSocketAddr(String target,
int defaultPort) {
if (target == null) {
throw new IllegalArgumentException("Target address cannot be null.");
}
int colonIndex = target.indexOf(':');
if (colonIndex < 0 && defaultPort == -1) {
throw new RuntimeException("Not a host:port pair: " + target);
}
String hostname;
int port = -1;
if (!target.contains("/")) {
if (colonIndex == -1) {
hostname = target;
} else {
// must be the old style :
hostname = target.substring(0, colonIndex);
port = Integer.parseInt(target.substring(colonIndex + 1));
}
} else {
// a new uri
URI addr = new Path(target).toUri();
hostname = addr.getHost();
port = addr.getPort();
}
if (port == -1) {
port = defaultPort;
}
if (getStaticResolution(hostname) != null) {
hostname = getStaticResolution(hostname);
}
return new InetSocketAddress(hostname, port);
}
/**
* Adds a static resolution for host. This can be used for setting up
* hostnames with names that are fake to point to a well known host. For e.g.
* in some testcases we require to have daemons with different hostnames
* running on the same machine. In order to create connections to these
* daemons, one can set up mappings from those hostnames to "localhost".
* {@link NetUtils#getStaticResolution(String)} can be used to query for
* the actual hostname.
* @param host
* @param resolvedName
*/
public static void addStaticResolution(String host, String resolvedName) {
synchronized (hostToResolved) {
hostToResolved.put(host, resolvedName);
}
}
/**
* Retrieves the resolved name for the passed host. The resolved name must
* have been set earlier using
* {@link NetUtils#addStaticResolution(String, String)}
* @param host
* @return the resolution
*/
public static String getStaticResolution(String host) {
synchronized (hostToResolved) {
return hostToResolved.get(host);
}
}
/**
* This is used to get all the resolutions that were added using
* {@link NetUtils#addStaticResolution(String, String)}. The return
* value is a List each element of which contains an array of String
* of the form String[0]=hostname, String[1]=resolved-hostname
* @return the list of resolutions
*/
public static List getAllStaticResolutions() {
synchronized (hostToResolved) {
Set >entries = hostToResolved.entrySet();
if (entries.size() == 0) {
return null;
}
List l = new ArrayList(entries.size());
for (Entry e : entries) {
l.add(new String[] {e.getKey(), e.getValue()});
}
return l;
}
}
/**
* Returns InetSocketAddress that a client can use to
* connect to the server. Server.getListenerAddress() is not correct when
* the server binds to "0.0.0.0". This returns "127.0.0.1:port" when
* the getListenerAddress() returns "0.0.0.0:port".
*
* @param server
* @return socket address that a client can use to connect to the server.
*/
public static InetSocketAddress getConnectAddress(Server server) {
InetSocketAddress addr = server.getListenerAddress();
if (addr.getAddress().getHostAddress().equals("0.0.0.0")) {
addr = new InetSocketAddress("127.0.0.1", addr.getPort());
}
return addr;
}
/**
* Same as getInputStream(socket, socket.getSoTimeout()).
*
* From documentation for {@link #getInputStream(Socket, long)}:
* Returns InputStream for the socket. If the socket has an associated
* SocketChannel then it returns a
* {@link SocketInputStream} with the given timeout. If the socket does not
* have a channel, {@link Socket#getInputStream()} is returned. In the later
* case, the timeout argument is ignored and the timeout set with
* {@link Socket#setSoTimeout(int)} applies for reads.
*
* Any socket created using socket factories returned by {@link #NetUtils},
* must use this interface instead of {@link Socket#getInputStream()}.
*
* @see #getInputStream(Socket, long)
*
* @param socket
* @return InputStream for reading from the socket.
* @throws IOException
*/
public static InputStream getInputStream(Socket socket)
throws IOException {
return getInputStream(socket, socket.getSoTimeout());
}
/**
* Returns InputStream for the socket. If the socket has an associated
* SocketChannel then it returns a
* {@link SocketInputStream} with the given timeout. If the socket does not
* have a channel, {@link Socket#getInputStream()} is returned. In the later
* case, the timeout argument is ignored and the timeout set with
* {@link Socket#setSoTimeout(int)} applies for reads.
*
* Any socket created using socket factories returned by {@link #NetUtils},
* must use this interface instead of {@link Socket#getInputStream()}.
*
* @see Socket#getChannel()
*
* @param socket
* @param timeout timeout in milliseconds. This may not always apply. zero
* for waiting as long as necessary.
* @return InputStream for reading from the socket.
* @throws IOException
*/
public static InputStream getInputStream(Socket socket, long timeout)
throws IOException {
return (socket.getChannel() == null) ?
socket.getInputStream() : new SocketInputStream(socket, timeout);
}
/**
* Same as getOutputStream(socket, 0). Timeout of zero implies write will
* wait until data is available.
*
* From documentation for {@link #getOutputStream(Socket, long)} :
* Returns OutputStream for the socket. If the socket has an associated
* SocketChannel then it returns a
* {@link SocketOutputStream} with the given timeout. If the socket does not
* have a channel, {@link Socket#getOutputStream()} is returned. In the later
* case, the timeout argument is ignored and the write will wait until
* data is available.
*
* Any socket created using socket factories returned by {@link #NetUtils},
* must use this interface instead of {@link Socket#getOutputStream()}.
*
* @see #getOutputStream(Socket, long)
*
* @param socket
* @return OutputStream for writing to the socket.
* @throws IOException
*/
public static OutputStream getOutputStream(Socket socket)
throws IOException {
return getOutputStream(socket, 0);
}
/**
* Returns OutputStream for the socket. If the socket has an associated
* SocketChannel then it returns a
* {@link SocketOutputStream} with the given timeout. If the socket does not
* have a channel, {@link Socket#getOutputStream()} is returned. In the later
* case, the timeout argument is ignored and the write will wait until
* data is available.
*
* Any socket created using socket factories returned by {@link #NetUtils},
* must use this interface instead of {@link Socket#getOutputStream()}.
*
* @see Socket#getChannel()
*
* @param socket
* @param timeout timeout in milliseconds. This may not always apply. zero
* for waiting as long as necessary.
* @return OutputStream for writing to the socket.
* @throws IOException
*/
public static OutputStream getOutputStream(Socket socket, long timeout)
throws IOException {
return (socket.getChannel() == null) ?
socket.getOutputStream() : new SocketOutputStream(socket, timeout);
}
/**
* This is a drop-in replacement for
* {@link Socket#connect(SocketAddress, int)}.
* In the case of normal sockets that don't have associated channels, this
* just invokes socket.connect(endpoint, timeout). If
* socket.getChannel() returns a non-null channel,
* connect is implemented using Hadoop's selectors. This is done mainly
* to avoid Sun's connect implementation from creating thread-local
* selectors, since Hadoop does not have control on when these are closed
* and could end up taking all the available file descriptors.
*
* @see java.net.Socket#connect(java.net.SocketAddress, int)
*
* @param socket
* @param endpoint
* @param timeout - timeout in milliseconds
*/
public static void connect(Socket socket,
SocketAddress endpoint,
int timeout) throws IOException {
if (socket == null || endpoint == null || timeout < 0) {
throw new IllegalArgumentException("Illegal argument for connect()");
}
SocketChannel ch = socket.getChannel();
if (ch == null) {
// let the default implementation handle it.
socket.connect(endpoint, timeout);
} else {
SocketIOWithTimeout.connect(ch, endpoint, timeout);
}
// There is a very rare case allowed by the TCP specification, such that
// if we are trying to connect to an endpoint on the local machine,
// and we end up choosing an ephemeral port equal to the destination port,
// we will actually end up getting connected to ourself (ie any data we
// send just comes right back). This is only possible if the target
// daemon is down, so we'll treat it like connection refused.
if (socket.getLocalPort() == socket.getPort() &&
socket.getLocalAddress().equals(socket.getInetAddress())) {
LOG.info("Detected a loopback TCP socket, disconnecting it");
socket.close();
throw new ConnectException(
"Localhost targeted connection resulted in a loopback. " +
"No daemon is listening on the target port.");
}
}
/**
* Given a string representation of a host, return its ip address
* in textual presentation.
*
* @param name a string representation of a host:
* either a textual representation its IP address or its host name
* @return its IP address in the string format
*/
public static String normalizeHostName(String name) {
if (Character.digit(name.charAt(0), 10) != -1) { // it is an IP
return name;
} else {
try {
InetAddress ipAddress = InetAddress.getByName(name);
return ipAddress.getHostAddress();
} catch (UnknownHostException e) {
return name;
}
}
}
/**
* Given a collection of string representation of hosts, return a list of
* corresponding IP addresses in the textual representation.
*
* @param names a collection of string representations of hosts
* @return a list of corresponding IP addresses in the string format
* @see #normalizeHostName(String)
*/
public static List normalizeHostNames(Collection names) {
List hostNames = new ArrayList(names.size());
for (String name : names) {
hostNames.add(normalizeHostName(name));
}
return hostNames;
}
/**
* Attempt to obtain the host name of a name specified by ip address.
* Check that the node name is an ip addr and if so, attempt to determine
* its host name. If the name is not an IP addr, or the actual name cannot
* be determined, return null.
*
* @return Host name or null
*/
private static final Pattern ipPattern = // Pattern for matching hostname to ip:port
Pattern.compile("\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}:?\\d*");
public static String getHostNameOfIP(String ip) {
// If name is not an ip addr, don't bother looking it up
if(!ipPattern.matcher(ip).matches())
return null;
String hostname = "";
try {
String n = ip.substring(0, ip.indexOf(':'));
hostname = InetAddress.getByName(n).getHostName();
} catch (UnknownHostException e) {
return null;
}
return hostname;
}
/**
* Return hostname without throwing exception.
* @return hostname
*/
public static String getHostname() {
try {return "" + InetAddress.getLocalHost();}
catch(UnknownHostException uhe) {return "" + uhe;}
}
}