pankaj

Merge branch 'master' of ssh://gerrit.onlab.us:29418/onos-next

Showing 21 changed files with 61 additions and 879 deletions
......@@ -35,6 +35,12 @@
</dependency>
<dependency>
<groupId>org.onlab.onos</groupId>
<artifactId>onlab-netty</artifactId>
<version>${project.version}</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
</dependency>
......@@ -51,15 +57,6 @@
<groupId>de.javakaffee</groupId>
<artifactId>kryo-serializers</artifactId>
</dependency>
<dependency>
<groupId>io.netty</groupId>
<artifactId>netty-all</artifactId>
</dependency>
<dependency>
<groupId>commons-pool</groupId>
<artifactId>commons-pool</artifactId>
<version>1.6</version>
</dependency>
</dependencies>
<build>
......
......@@ -23,10 +23,10 @@ import org.onlab.onos.store.cluster.messaging.ClusterCommunicationService;
import org.onlab.onos.store.cluster.messaging.ClusterMessage;
import org.onlab.onos.store.cluster.messaging.ClusterMessageHandler;
import org.onlab.onos.store.cluster.messaging.MessageSubject;
import org.onlab.onos.store.messaging.Endpoint;
import org.onlab.onos.store.messaging.Message;
import org.onlab.onos.store.messaging.MessageHandler;
import org.onlab.onos.store.messaging.MessagingService;
import org.onlab.netty.Endpoint;
import org.onlab.netty.Message;
import org.onlab.netty.MessageHandler;
import org.onlab.netty.MessagingService;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
......
package org.onlab.onos.store.messaging;
/**
* Representation of a TCP/UDP communication end point.
*/
public class Endpoint {
private final int port;
private final String host;
public Endpoint(String host, int port) {
this.host = host;
this.port = port;
}
public String host() {
return host;
}
public int port() {
return port;
}
@Override
public String toString() {
return "Endpoint [port=" + port + ", host=" + host + "]";
}
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + ((host == null) ? 0 : host.hashCode());
result = prime * result + port;
return result;
}
@Override
public boolean equals(Object obj) {
if (this == obj) {
return true;
}
if (obj == null) {
return false;
}
if (getClass() != obj.getClass()) {
return false;
}
Endpoint other = (Endpoint) obj;
if (host == null) {
if (other.host != null) {
return false;
}
} else if (!host.equals(other.host)) {
return false;
}
if (port != other.port) {
return false;
}
return true;
}
}
package org.onlab.onos.store.messaging;
import java.io.IOException;
/**
* A unit of communication.
* Has a payload. Also supports a feature to respond back to the sender.
*/
public interface Message {
/**
* Returns the payload of this message.
* @return message payload.
*/
public Object payload();
/**
* Sends a reply back to the sender of this messge.
* @param data payload of the response.
* @throws IOException if there is a communication error.
*/
public void respond(Object data) throws IOException;
}
package org.onlab.onos.store.messaging;
import java.io.IOException;
/**
* Handler for a message.
*/
public interface MessageHandler {
/**
* Handles the message.
* @param message message.
* @throws IOException.
*/
public void handle(Message message) throws IOException;
}
package org.onlab.onos.store.messaging;
import java.io.IOException;
/**
* Interface for low level messaging primitives.
*/
public interface MessagingService {
/**
* Sends a message asynchronously to the specified communication end point.
* The message is specified using the type and payload.
* @param ep end point to send the message to.
* @param type type of message.
* @param payload message payload.
* @throws IOException
*/
public void sendAsync(Endpoint ep, String type, Object payload) throws IOException;
/**
* Sends a message synchronously and waits for a response.
* @param ep end point to send the message to.
* @param type type of message.
* @param payload message payload.
* @return a response future
* @throws IOException
*/
public <T> Response<T> sendAndReceive(Endpoint ep, String type, Object payload) throws IOException;
/**
* Registers a new message handler for message type.
* @param type message type.
* @param handler message handler
*/
public void registerHandler(String type, MessageHandler handler);
/**
* Unregister current handler, if one exists for message type.
* @param type message type
*/
public void unregisterHandler(String type);
}
package org.onlab.onos.store.messaging;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
/**
* Response object returned when making synchronous requests.
* Can you used to check is a response is ready and/or wait for a response
* to become available.
*
* @param <T> type of response.
*/
public interface Response<T> {
/**
* Gets the response waiting for a designated timeout period.
* @param timeout timeout period (since request was sent out)
* @param tu unit of time.
* @return response
* @throws TimeoutException if the timeout expires before the response arrives.
*/
public T get(long timeout, TimeUnit tu) throws TimeoutException;
/**
* Gets the response waiting for indefinite timeout period.
* @return response
* @throws InterruptedException if the thread is interrupted before the response arrives.
*/
public T get() throws InterruptedException;
/**
* Checks if the response is ready without blocking.
* @return true if response is ready, false otherwise.
*/
public boolean isReady();
}
package org.onlab.onos.store.messaging.impl;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import org.onlab.onos.store.messaging.Response;
/**
* An asynchronous response.
* This class provides a base implementation of Response, with methods to retrieve the
* result and query to see if the result is ready. The result can only be retrieved when
* it is ready and the get methods will block if the result is not ready yet.
* @param <T> type of response.
*/
public class AsyncResponse<T> implements Response<T> {
private T value;
private boolean done = false;
private final long start = System.nanoTime();
@Override
public T get(long timeout, TimeUnit tu) throws TimeoutException {
timeout = tu.toNanos(timeout);
boolean interrupted = false;
try {
synchronized (this) {
while (!done) {
try {
long timeRemaining = timeout - (System.nanoTime() - start);
if (timeRemaining <= 0) {
throw new TimeoutException("Operation timed out.");
}
TimeUnit.NANOSECONDS.timedWait(this, timeRemaining);
} catch (InterruptedException e) {
interrupted = true;
}
}
}
} finally {
if (interrupted) {
Thread.currentThread().interrupt();
}
}
return value;
}
@Override
public T get() throws InterruptedException {
throw new UnsupportedOperationException();
}
@Override
public boolean isReady() {
return done;
}
/**
* Sets response value and unblocks any thread blocking on the response to become
* available.
* @param data response data.
*/
@SuppressWarnings("unchecked")
public synchronized void setResponse(Object data) {
if (!done) {
done = true;
value = (T) data;
this.notifyAll();
}
}
}
package org.onlab.onos.store.messaging.impl;
import java.io.IOException;
import org.onlab.onos.store.messaging.Message;
import org.onlab.onos.store.messaging.MessageHandler;
/**
* Message handler that echos the message back to the sender.
*/
public class EchoHandler implements MessageHandler {
@Override
public void handle(Message message) throws IOException {
System.out.println("Received: " + message.payload() + ". Echoing it back to the sender.");
message.respond(message.payload());
}
}
package org.onlab.onos.store.messaging.impl;
import java.io.IOException;
import org.onlab.onos.store.messaging.Endpoint;
import org.onlab.onos.store.messaging.Message;
/**
* Internal message representation with additional attributes
* for supporting, synchronous request/reply behavior.
*/
public final class InternalMessage implements Message {
private long id;
private Endpoint sender;
private String type;
private Object payload;
private transient NettyMessagingService messagingService;
public static final String REPLY_MESSAGE_TYPE = "NETTY_MESSAGIG_REQUEST_REPLY";
// Must be created using the Builder.
private InternalMessage() {}
public long id() {
return id;
}
public String type() {
return type;
}
public Endpoint sender() {
return sender;
}
@Override
public Object payload() {
return payload;
}
@Override
public void respond(Object data) throws IOException {
Builder builder = new Builder(messagingService);
InternalMessage message = builder.withId(this.id)
// FIXME: Sender should be messagingService.localEp.
.withSender(this.sender)
.withPayload(data)
.withType(REPLY_MESSAGE_TYPE)
.build();
messagingService.sendAsync(sender, message);
}
/**
* Builder for InternalMessages.
*/
public static class Builder {
private InternalMessage message;
public Builder(NettyMessagingService messagingService) {
message = new InternalMessage();
message.messagingService = messagingService;
}
public Builder withId(long id) {
message.id = id;
return this;
}
public Builder withType(String type) {
message.type = type;
return this;
}
public Builder withSender(Endpoint sender) {
message.sender = sender;
return this;
}
public Builder withPayload(Object payload) {
message.payload = payload;
return this;
}
public InternalMessage build() {
return message;
}
}
}
package org.onlab.onos.store.messaging.impl;
import org.onlab.util.KryoPool;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.util.ArrayList;
import java.util.HashMap;
/**
* Kryo Serializer.
*/
public class KryoSerializer implements Serializer {
private final Logger log = LoggerFactory.getLogger(getClass());
private KryoPool serializerPool;
public KryoSerializer() {
setupKryoPool();
}
/**
* Sets up the common serialzers pool.
*/
protected void setupKryoPool() {
// FIXME Slice out types used in common to separate pool/namespace.
serializerPool = KryoPool.newBuilder()
.register(ArrayList.class,
HashMap.class,
ArrayList.class
)
.build()
.populate(1);
}
@Override
public Object decode(byte[] data) {
return serializerPool.deserialize(data);
}
@Override
public byte[] encode(Object payload) {
return serializerPool.serialize(payload);
}
}
package org.onlab.onos.store.messaging.impl;
import org.onlab.onos.store.messaging.Message;
import org.onlab.onos.store.messaging.MessageHandler;
/**
* A MessageHandler that simply logs the information.
*/
public class LoggingHandler implements MessageHandler {
@Override
public void handle(Message message) {
System.out.println("Received: " + message.payload());
}
}
\ No newline at end of file
package org.onlab.onos.store.messaging.impl;
import java.util.Arrays;
import java.util.List;
import static com.google.common.base.Preconditions.checkState;
import org.onlab.onos.store.messaging.Endpoint;
import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.ByteToMessageDecoder;
/**
* Decode bytes into a InrenalMessage.
*/
public class MessageDecoder extends ByteToMessageDecoder {
private final NettyMessagingService messagingService;
private final Serializer serializer;
public MessageDecoder(NettyMessagingService messagingService, Serializer serializer) {
this.messagingService = messagingService;
this.serializer = serializer;
}
@Override
protected void decode(ChannelHandlerContext context, ByteBuf in,
List<Object> messages) throws Exception {
byte[] preamble = in.readBytes(MessageEncoder.PREAMBLE.length).array();
checkState(Arrays.equals(MessageEncoder.PREAMBLE, preamble), "Message has wrong preamble");
// read message Id.
long id = in.readLong();
// read message type; first read size and then bytes.
String type = new String(in.readBytes(in.readInt()).array());
// read sender host name; first read size and then bytes.
String host = new String(in.readBytes(in.readInt()).array());
// read sender port.
int port = in.readInt();
Endpoint sender = new Endpoint(host, port);
// read message payload; first read size and then bytes.
Object payload = serializer.decode(in.readBytes(in.readInt()).array());
InternalMessage message = new InternalMessage.Builder(messagingService)
.withId(id)
.withSender(sender)
.withType(type)
.withPayload(payload)
.build();
messages.add(message);
}
}
package org.onlab.onos.store.messaging.impl;
import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.MessageToByteEncoder;
/**
* Encode InternalMessage out into a byte buffer.
*/
public class MessageEncoder extends MessageToByteEncoder<InternalMessage> {
// onosiscool in ascii
public static final byte[] PREAMBLE = "onosiscool".getBytes();
private final Serializer serializer;
public MessageEncoder(Serializer serializer) {
this.serializer = serializer;
}
@Override
protected void encode(ChannelHandlerContext context, InternalMessage message,
ByteBuf out) throws Exception {
// write preamble
out.writeBytes(PREAMBLE);
// write id
out.writeLong(message.id());
// write type length
out.writeInt(message.type().length());
// write type
out.writeBytes(message.type().getBytes());
// write sender host name size
out.writeInt(message.sender().host().length());
// write sender host name.
out.writeBytes(message.sender().host().getBytes());
// write port
out.writeInt(message.sender().port());
try {
serializer.encode(message.payload());
} catch (Exception e) {
e.printStackTrace();
}
byte[] payload = serializer.encode(message.payload());
// write payload length.
out.writeInt(payload.length);
// write payload bytes
out.writeBytes(payload);
}
}
package org.onlab.onos.store.messaging.impl;
import java.io.IOException;
import java.net.UnknownHostException;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.TimeUnit;
import io.netty.bootstrap.Bootstrap;
import io.netty.bootstrap.ServerBootstrap;
import io.netty.buffer.PooledByteBufAllocator;
import io.netty.channel.Channel;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelOption;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.SimpleChannelInboundHandler;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import io.netty.channel.socket.nio.NioSocketChannel;
import org.apache.commons.lang.math.RandomUtils;
import org.apache.commons.pool.KeyedObjectPool;
import org.apache.commons.pool.KeyedPoolableObjectFactory;
import org.apache.commons.pool.impl.GenericKeyedObjectPool;
import org.apache.felix.scr.annotations.Activate;
import org.apache.felix.scr.annotations.Component;
import org.apache.felix.scr.annotations.Deactivate;
import org.apache.felix.scr.annotations.Reference;
import org.apache.felix.scr.annotations.ReferenceCardinality;
import org.apache.felix.scr.annotations.Service;
import org.onlab.onos.store.messaging.Endpoint;
import org.onlab.onos.store.messaging.MessageHandler;
import org.onlab.onos.store.messaging.MessagingService;
import org.onlab.onos.store.messaging.Response;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.google.common.cache.Cache;
import com.google.common.cache.CacheBuilder;
/**
* A Netty based implementation of MessagingService.
*/
@Component(immediate = true)
@Service
public class NettyMessagingService implements MessagingService {
private final Logger log = LoggerFactory.getLogger(getClass());
private KeyedObjectPool<Endpoint, Channel> channels =
new GenericKeyedObjectPool<Endpoint, Channel>(new OnosCommunicationChannelFactory());
private final int port;
private final EventLoopGroup bossGroup = new NioEventLoopGroup();
private final EventLoopGroup workerGroup = new NioEventLoopGroup();
private final ConcurrentMap<String, MessageHandler> handlers = new ConcurrentHashMap<>();
private Cache<Long, AsyncResponse<?>> responseFutures;
private final Endpoint localEp;
@Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
protected Serializer serializer;
public NettyMessagingService() {
// TODO: Default port should be configurable.
this(8080);
}
// FIXME: Constructor should not throw exceptions.
public NettyMessagingService(int port) {
this.port = port;
try {
localEp = new Endpoint(java.net.InetAddress.getLocalHost().getHostName(), port);
} catch (UnknownHostException e) {
// bailing out.
throw new RuntimeException(e);
}
}
@Activate
public void activate() throws Exception {
responseFutures = CacheBuilder.newBuilder()
.maximumSize(100000)
.weakValues()
// TODO: Once the entry expires, notify blocking threads (if any).
.expireAfterWrite(10, TimeUnit.MINUTES)
.build();
startAcceptingConnections();
}
@Deactivate
public void deactivate() throws Exception {
channels.close();
bossGroup.shutdownGracefully();
workerGroup.shutdownGracefully();
}
@Override
public void sendAsync(Endpoint ep, String type, Object payload) throws IOException {
InternalMessage message = new InternalMessage.Builder(this)
.withId(RandomUtils.nextLong())
.withSender(localEp)
.withType(type)
.withPayload(payload)
.build();
sendAsync(ep, message);
}
protected void sendAsync(Endpoint ep, InternalMessage message) throws IOException {
Channel channel = null;
try {
channel = channels.borrowObject(ep);
channel.eventLoop().execute(new WriteTask(channel, message));
} catch (Exception e) {
throw new IOException(e);
} finally {
try {
channels.returnObject(ep, channel);
} catch (Exception e) {
log.warn("Error returning object back to the pool", e);
// ignored.
}
}
}
@Override
public <T> Response<T> sendAndReceive(Endpoint ep, String type, Object payload)
throws IOException {
AsyncResponse<T> futureResponse = new AsyncResponse<T>();
Long messageId = RandomUtils.nextLong();
responseFutures.put(messageId, futureResponse);
InternalMessage message = new InternalMessage.Builder(this)
.withId(messageId)
.withSender(localEp)
.withType(type)
.withPayload(payload)
.build();
sendAsync(ep, message);
return futureResponse;
}
@Override
public void registerHandler(String type, MessageHandler handler) {
// TODO: Is this the right semantics for handler registration?
handlers.putIfAbsent(type, handler);
}
public void unregisterHandler(String type) {
handlers.remove(type);
}
private MessageHandler getMessageHandler(String type) {
return handlers.get(type);
}
private void startAcceptingConnections() throws InterruptedException {
ServerBootstrap b = new ServerBootstrap();
b.option(ChannelOption.ALLOCATOR, PooledByteBufAllocator.DEFAULT);
b.group(bossGroup, workerGroup)
.channel(NioServerSocketChannel.class)
.childHandler(new OnosCommunicationChannelInitializer())
.option(ChannelOption.SO_BACKLOG, 128)
.childOption(ChannelOption.SO_KEEPALIVE, true);
// Bind and start to accept incoming connections.
b.bind(port).sync();
}
private class OnosCommunicationChannelFactory
implements KeyedPoolableObjectFactory<Endpoint, Channel> {
@Override
public void activateObject(Endpoint endpoint, Channel channel)
throws Exception {
}
@Override
public void destroyObject(Endpoint ep, Channel channel) throws Exception {
channel.close();
}
@Override
public Channel makeObject(Endpoint ep) throws Exception {
Bootstrap b = new Bootstrap();
b.option(ChannelOption.ALLOCATOR, PooledByteBufAllocator.DEFAULT);
b.group(workerGroup);
// TODO: Make this faster:
// http://normanmaurer.me/presentations/2014-facebook-eng-netty/slides.html#37.0
b.channel(NioSocketChannel.class);
b.option(ChannelOption.SO_KEEPALIVE, true);
b.handler(new OnosCommunicationChannelInitializer());
// Start the client.
ChannelFuture f = b.connect(ep.host(), ep.port()).sync();
return f.channel();
}
@Override
public void passivateObject(Endpoint ep, Channel channel)
throws Exception {
}
@Override
public boolean validateObject(Endpoint ep, Channel channel) {
return channel.isOpen();
}
}
private class OnosCommunicationChannelInitializer extends ChannelInitializer<SocketChannel> {
@Override
protected void initChannel(SocketChannel channel) throws Exception {
channel.pipeline()
.addLast(new MessageEncoder(serializer))
.addLast(new MessageDecoder(NettyMessagingService.this, serializer))
.addLast(new NettyMessagingService.InboundMessageDispatcher());
}
}
private class WriteTask implements Runnable {
private final Object message;
private final Channel channel;
public WriteTask(Channel channel, Object message) {
this.message = message;
this.channel = channel;
}
@Override
public void run() {
channel.writeAndFlush(message);
}
}
private class InboundMessageDispatcher extends SimpleChannelInboundHandler<InternalMessage> {
@Override
protected void channelRead0(ChannelHandlerContext ctx, InternalMessage message) throws Exception {
String type = message.type();
if (type.equals(InternalMessage.REPLY_MESSAGE_TYPE)) {
try {
AsyncResponse<?> futureResponse =
NettyMessagingService.this.responseFutures.getIfPresent(message.id());
if (futureResponse != null) {
futureResponse.setResponse(message.payload());
}
log.warn("Received a reply. But was unable to locate the request handle");
} finally {
NettyMessagingService.this.responseFutures.invalidate(message.id());
}
return;
}
MessageHandler handler = NettyMessagingService.this.getMessageHandler(type);
handler.handle(message);
}
}
}
package org.onlab.onos.store.messaging.impl;
/**
* Interface for encoding/decoding message payloads.
*/
public interface Serializer {
/**
* Decodes the specified byte array to a POJO.
*
* @param data byte array.
* @return POJO
*/
Object decode(byte[] data);
/**
* Encodes the specified POJO into a byte array.
*
* @param data POJO to be encoded
* @return byte array.
*/
byte[] encode(Object message);
}
package org.onlab.onos.store.messaging.impl;
import java.util.concurrent.TimeUnit;
import org.onlab.onos.store.messaging.Endpoint;
import org.onlab.onos.store.messaging.Response;
public final class SimpleClient {
private SimpleClient() {}
public static void main(String... args) throws Exception {
NettyMessagingService messaging = new TestNettyMessagingService(9081);
messaging.activate();
messaging.sendAsync(new Endpoint("localhost", 8080), "simple", "Hello World");
Response<String> response = messaging.sendAndReceive(new Endpoint("localhost", 8080), "echo", "Hello World");
System.out.println("Got back:" + response.get(2, TimeUnit.SECONDS));
}
public static class TestNettyMessagingService extends NettyMessagingService {
public TestNettyMessagingService(int port) throws Exception {
super(port);
Serializer serializer = new KryoSerializer();
this.serializer = serializer;
}
}
}
package org.onlab.onos.store.messaging.impl;
public final class SimpleServer {
private SimpleServer() {}
public static void main(String... args) throws Exception {
NettyMessagingService server = new TestNettyMessagingService();
server.activate();
server.registerHandler("simple", new LoggingHandler());
server.registerHandler("echo", new EchoHandler());
}
public static class TestNettyMessagingService extends NettyMessagingService {
protected TestNettyMessagingService() {
Serializer serializer = new KryoSerializer();
this.serializer = serializer;
}
}
}
......@@ -7,7 +7,7 @@ import org.junit.Test;
import org.onlab.onos.cluster.DefaultControllerNode;
import org.onlab.onos.cluster.NodeId;
import org.onlab.onos.store.cluster.messaging.impl.OnosClusterCommunicationManager;
import org.onlab.onos.store.messaging.impl.NettyMessagingService;
import org.onlab.netty.NettyMessagingService;
import org.onlab.packet.IpPrefix;
import java.util.concurrent.CountDownLatch;
......
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.onlab.onos</groupId>
<artifactId>onlab-utils</artifactId>
<version>1.0.0-SNAPSHOT</version>
<relativePath>../pom.xml</relativePath>
</parent>
<artifactId>onlab-netty</artifactId>
<packaging>bundle</packaging>
<description>Network I/O using Netty framework</description>
<dependencies>
<dependency>
<groupId>com.google.guava</groupId>
<artifactId>guava-testlib</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.onlab.onos</groupId>
<artifactId>onlab-misc</artifactId>
</dependency>
<dependency>
<groupId>org.onlab.onos</groupId>
<artifactId>onlab-junit</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>de.javakaffee</groupId>
<artifactId>kryo-serializers</artifactId>
</dependency>
<dependency>
<groupId>io.netty</groupId>
<artifactId>netty-all</artifactId>
</dependency>
<dependency>
<groupId>commons-pool</groupId>
<artifactId>commons-pool</artifactId>
<version>1.6</version>
</dependency>
</dependencies>
</project>
......@@ -19,6 +19,7 @@
<modules>
<module>junit</module>
<module>misc</module>
<module>netty</module>
<module>nio</module>
<module>osgi</module>
<module>rest</module>
......