Recently，I use netty 4 write a client and server，client send five message to server，but client can only receive one response from server，here is my codes.
DTO:RpcRequest
package com.huawei.simple.rpc.base.request.dto;
import lombok.AllArgsConstructor;
import lombok.Getter;
import lombok.NoArgsConstructor;
import lombok.Setter;
import lombok.ToString;
import java.lang.reflect.Parameter;
#Setter
#Getter
#NoArgsConstructor
#AllArgsConstructor
#ToString
public class RpcRequest {
private String requestId;
private String interfaceName;
private String methodName;
}
DTO:RpcResponse
package com.huawei.simple.rpc.base.response.dto;
import lombok.AllArgsConstructor;
import lombok.Getter;
import lombok.NoArgsConstructor;
import lombok.Setter;
import lombok.ToString;
#Setter
#Getter
#NoArgsConstructor
#AllArgsConstructor
#ToString
public class RpcResponse {
private String requestId;
private String responseMessage;
private int responseCode;
private Object responseBody;
}
Codec
public class ResponseDecoder extends ByteToMessageDecoder {
private static ObjectMapper mapper = new ObjectMapper();
#Override
protected void decode(ChannelHandlerContext channelHandlerContext, ByteBuf byteBuf, List<Object> list) throws Exception {
if (byteBuf.readableBytes() < 4) {
return;
}
byteBuf.markReaderIndex();
int dataLength = byteBuf.readInt();
if (byteBuf.readableBytes() < dataLength) {
byteBuf.resetReaderIndex();
return;
}
byte[] data = new byte[dataLength];
byteBuf.readBytes(data);
RpcResponse response = mapper.readValue(data, RpcResponse.class);
list.add(response);
}
}
public class ResponseEncoder extends MessageToByteEncoder<RpcResponse> {
private static ObjectMapper mapper = new ObjectMapper();
#Override
protected void encode(ChannelHandlerContext channelHandlerContext, RpcResponse rpcResponse, ByteBuf byteBuf) throws Exception {
byte[] bytes = mapper.writeValueAsBytes(rpcResponse);
int dataLength = bytes.length;
byteBuf.writeInt(dataLength);
byteBuf.writeBytes(bytes);
byteBuf.writeBytes(SerializationUtil.serialize(rpcResponse));
}
}
public class RequestDecoder extends ByteToMessageDecoder {
private static ObjectMapper mapper = new ObjectMapper();
#Override
protected void decode(ChannelHandlerContext channelHandlerContext, ByteBuf byteBuf, List<Object> list) throws Exception {
if (byteBuf.readableBytes() < 4) {
return;
}
byteBuf.markReaderIndex();
int dataLength = byteBuf.readInt();
if (byteBuf.readableBytes() < dataLength) {
byteBuf.resetReaderIndex();
return;
}
byte[] data = new byte[dataLength];
byteBuf.readBytes(data);
RpcRequest request = mapper.readValue(data, RpcRequest.class);
list.add(request);
}
}
public class RequestEncoder extends MessageToByteEncoder<RpcRequest> {
private static ObjectMapper mapper = new ObjectMapper();
#Override
protected void encode(ChannelHandlerContext channelHandlerContext, RpcRequest rpcRequest, ByteBuf byteBuf) throws Exception {
byte[] bytes = mapper.writeValueAsBytes(rpcRequest);
int dataLength = bytes.length;
byteBuf.writeInt(dataLength);
byteBuf.writeBytes(bytes);
}
}
Client
public class RpcClient {
public static void main(String[] args) throws Exception {
RpcClient server = new RpcClient();
server.build();
}
public void build() {
NioEventLoopGroup boss = new NioEventLoopGroup();
Bootstrap s = new Bootstrap();
s.group(boss).channel(NioSocketChannel.class)
.option(ChannelOption.TCP_NODELAY,true)
.handler(new ChannelInitializer<SocketChannel>() {
#Override
protected void initChannel(SocketChannel socketChannel) throws Exception {
socketChannel.pipeline().addLast(new RequestEncoder());
socketChannel.pipeline().addLast(new ResponseDecoder());
socketChannel.pipeline().addLast(new RpcClientHandler());
}
});
try {
ChannelFuture future = s.connect(new InetSocketAddress("localhost",8080)).sync();
future.channel().closeFuture().sync();
} catch (InterruptedException e) {
e.printStackTrace();
} finally {
boss.shutdownGracefully();
}
}
}
public class RpcClientHandler extends ChannelInboundHandlerAdapter {
private static AtomicInteger id = new AtomicInteger(1);
#Override
public void channelActive(ChannelHandlerContext ctx) throws Exception {
for (int i = 0; i < 5; i++) {
RpcRequest request = new RpcRequest();
request.setRequestId(id.getAndIncrement() + "");
request.setMethodName("helloWorld");
request.setInterfaceName("interface");
ChannelFuture future = ctx.writeAndFlush(request);
future.addListener(new ChannelFutureListener() {
#Override
public void operationComplete(ChannelFuture channelFuture) throws Exception {
if (channelFuture.isSuccess()) {
System.out.println("Success");
}
}
});
TimeUnit.SECONDS.sleep(5);
}
}
#Override
public void channelInactive(ChannelHandlerContext ctx) throws Exception {
super.channelInactive(ctx);
}
#Override
public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
RpcResponse response = (RpcResponse) msg;
System.out.println("get reponse from server " + response.toString());
}
#Override
public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {
super.channelReadComplete(ctx);
}
#Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
super.exceptionCaught(ctx, cause);
}
}
Server
public class RpcServer {
public static void main(String[] args) throws Exception {
RpcServer server = new RpcServer();
server.build();
}
public void build() {
NioEventLoopGroup boss = new NioEventLoopGroup();
NioEventLoopGroup worker = new NioEventLoopGroup();
ServerBootstrap s = new ServerBootstrap();
s.group(boss, worker).channel(NioServerSocketChannel.class)
.option(ChannelOption.TCP_NODELAY, true)
.option(ChannelOption.SO_BACKLOG, 10)
.handler(new LoggingHandler(LogLevel.DEBUG))
.childHandler(new ChannelInitializer<SocketChannel>() {
#Override
protected void initChannel(SocketChannel socketChannel) throws Exception {
socketChannel.pipeline().addLast(new RequestDecoder());
socketChannel.pipeline().addLast(new ResponseEncoder());
socketChannel.pipeline().addLast(new RpcServerHandler());
}
});
try {
ChannelFuture future = s.bind(new InetSocketAddress("localhost", 8080)).sync();
future.channel().closeFuture().sync();
} catch (InterruptedException e) {
e.printStackTrace();
} finally {
boss.shutdownGracefully();
worker.shutdownGracefully();
}
}
}
public class RpcServerHandler extends ChannelInboundHandlerAdapter {
#Override
public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
RpcRequest request = (RpcRequest) msg;
System.out.println("get request from client " + request.toString());
RpcResponse response = new RpcResponse();
response.setRequestId(request.getRequestId());
ChannelFuture future = ctx.writeAndFlush(response);
future.addListener(new ChannelFutureListener() {
#Override
public void operationComplete(ChannelFuture channelFuture) throws Exception {
if (channelFuture.isDone()) {
System.out.println("Done");
} else if (channelFuture.isSuccess()) {
System.out.println("Success");
}
}
});
}
#Override
public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {
super.channelReadComplete(ctx);
}
#Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
super.exceptionCaught(ctx, cause);
}
}
The output is
Server:
get request from client RpcRequest(requestId=1, interfaceName=interface, methodName=helloWorld)
Done
get request from client RpcRequest(requestId=2, interfaceName=interface, methodName=helloWorld)
Done
get request from client RpcRequest(requestId=3, interfaceName=interface, methodName=helloWorld)
Done
get request from client RpcRequest(requestId=4, interfaceName=interface, methodName=helloWorld)
Done
get request from client RpcRequest(requestId=5, interfaceName=interface, methodName=helloWorld)
Done
Client
Success
Success
Success
Success
Success
get reponse from server RpcResponse(requestId=1,
responseMessage=null, responseCode=0, responseBody=null)
Why my client get only one response from server?
You either have made an error inside ResponseEncoder or inside ResponseDecoder (I'm guessing the first one.
public class ResponseDecoder extends ByteToMessageDecoder {
private static ObjectMapper mapper = new ObjectMapper();
#Override
protected void decode(ChannelHandlerContext channelHandlerContext, ByteBuf byteBuf, List<Object> list) throws Exception {
if (byteBuf.readableBytes() < 4) {
return;
}
byteBuf.markReaderIndex();
int dataLength = byteBuf.readInt();
if (byteBuf.readableBytes() < dataLength) {
byteBuf.resetReaderIndex();
return;
}
byte[] data = new byte[dataLength];
byteBuf.readBytes(data);
RpcResponse response = mapper.readValue(data, RpcResponse.class);
list.add(response);
}
}
public class ResponseEncoder extends MessageToByteEncoder<RpcResponse> {
private static ObjectMapper mapper = new ObjectMapper();
#Override
protected void encode(ChannelHandlerContext channelHandlerContext, RpcResponse rpcResponse, ByteBuf byteBuf) throws Exception {
byte[] bytes = mapper.writeValueAsBytes(rpcResponse);
int dataLength = bytes.length;
byteBuf.writeInt(dataLength);
byteBuf.writeBytes(bytes);
byteBuf.writeBytes(SerializationUtil.serialize(rpcResponse));
}
}
Your encoder writes a Response as:
int: length of bytes
bytes: The result of the mapper
serialize: the result of the serialize operation
But those are read inside the decoder as:
int: length of bytes
bytes: The result of the mapper
You either forgot to handle the extra bytes in the decoder, or send to much data.
This causes the appearance of the program not reading, as client is actually waiting for more data, as I am assuming the data of "serialize" does not start with a zero, causing unusually high values for the length inside the decoder.
I implemented a very basic EchoClient and EchoServer using the Netty package in JAVA. I am very much new to Netty . Below are the codes for my client , clientHandler , server and serverHandler.
My Client
public class EchoClient {
private final String host;
private final int port;
public EchoClient(String host, int port) {
this.host = host;
this.port = port;
}
public static void main(String[] args) throws Exception {
new EchoClient("127.0.0.1", 11235).start();
}
public void start() throws Exception {
EventLoopGroup group = new NioEventLoopGroup();
try {
Bootstrap b = new Bootstrap();
b.group(group).channel(NioSocketChannel.class)
.remoteAddress(new InetSocketAddress(host, port))
.handler(new ChannelInitializer<SocketChannel>() {
#Override
public void initChannel(SocketChannel ch) throws Exception {
ch.pipeline().addLast(new EchoClientHandler());
}
});
ChannelFuture future = b.connect().sync();
future.channel().closeFuture().sync();
} finally {
group.shutdownGracefully().sync();
}
}
}
My ClientHandler
public class EchoClientHandler extends SimpleChannelInboundHandler<ByteBuf>{
#Override
public void channelActive(ChannelHandlerContext ctx) {
System.out.println("Connected");
int i = 0;
while (i < 1000) {
ctx.writeAndFlush(Unpooled.copiedBuffer("Netty MAY rock!\n", CharsetUtil.UTF_8));
i++;
}
}
#Override
protected void channelRead0(ChannelHandlerContext ctx, ByteBuf in) throws Exception {
System.out.println(
"Client received: " + in.toString(CharsetUtil.UTF_8));
}
#Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause){
cause.printStackTrace();
ctx.close();
}
}
My Server
public class EchoServer {
private final int port;
public EchoServer(int port) {
this.port = port;
}
public static void main(String[] args) throws Exception {
new EchoServer(11235).start();
}
public void start() throws Exception {
EventLoopGroup group = new NioEventLoopGroup();
try {
ServerBootstrap b = new ServerBootstrap();
b.group(group)
.channel(NioServerSocketChannel.class)
.localAddress(new InetSocketAddress(port))
.childHandler(new ChannelInitializer<SocketChannel>() {
#Override
public void initChannel(SocketChannel ch) throws Exception {
System.out.println("New client connected: " + ch.localAddress());
ch.pipeline().addLast(new EchoServerHandler());
}
});
ChannelFuture f = b.bind().sync();
f.channel().closeFuture().sync();
} finally {
group.shutdownGracefully().sync();
}
}
}
My SeverHandler
public class EchoServerHandler extends ChannelInboundHandlerAdapter {
#Override
public void channelRead(ChannelHandlerContext ctx, Object msg) {
ByteBuf in = (ByteBuf) msg;
System.out.println("Server received: " + n.toString(CharsetUtil.UTF_8));
ctx.write(in);
}
#Override
public void channelReadComplete(ChannelHandlerContext ctx) {
ctx.writeAndFlush(Unpooled.EMPTY_BUFFER)
.addListener(ChannelFutureListener.CLOSE);
}
#Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
cause.printStackTrace();
ctx.close();
}
}
Now the problem is : when I write the while loop in the ClientHandler as i<10 or i<100 both the Server and Client can receive the sent messages but if I increase the iterations upto 1000 and 10000, the Sever is receiving message but not the client. Even the server is unable to receive 10000 messages(only some of the messages are received).
You close your server channel immediately after the first reading. Please remove .addListener(ChannelFutureListener.CLOSE) in channelReadComplete of your EchoServerHandler class.
I'm trying to write a simple echo server with Netty. I'm reading Netty in Action MEAP v8 to get down some theory and learn the core basics of Netty. The client connects successfully, but no messages get through from the client. I am able to telnet a message to the server and receive the response, so I guess the issue is on the client, I just have no idea what is wrong, due to me being new to Netty.
Here is the client:
public class Client {
private final String host;
private final int port;
public Client(String host, int port) {
this.host = host;
this.port = port;
}
public void start() throws Exception {
EventLoopGroup group = new NioEventLoopGroup();
try {
Bootstrap b = new Bootstrap();
b.group(group).channel(NioSocketChannel.class)
.remoteAddress(new InetSocketAddress(host, port))
.handler(new ChannelInitializer<SocketChannel>() {
#Override
public void initChannel(SocketChannel ch) throws Exception {
ch.pipeline().addLast(new EchoClientHandler());
}
});
ChannelFuture f = b.connect().sync();
f.channel().closeFuture().sync();
} finally {
group.shutdownGracefully().sync();
}
}
public static void main (String [] args) throws Exception {
new Client("127.0.0.1", 11235).start();
}
}
And the Client handler: (I did try appending '\r\n' to the sent message, but that did not make a difference, which I found here: Netty Client to Server message)
#Sharable
public class EchoClientHandler extends SimpleChannelInboundHandler<ByteBuf> {
public void channelActive(ChannelHandlerContext ctx) {
System.out.println("Connected");
ctx.write(Unpooled.copiedBuffer("Netty MAY rock!", CharsetUtil.UTF_8));
}
protected void channelRead0(ChannelHandlerContext ctx, ByteBuf in) throws Exception {
System.out.println(
"Client received: " + in.toString(CharsetUtil.UTF_8));
}
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
cause.printStackTrace();
ctx.close();
}
}
The server:
public class EchoServer {
private final int port;
public EchoServer(int port) {
this.port = port;
}
public void start() throws Exception {
EventLoopGroup group = new NioEventLoopGroup();
try {
ServerBootstrap b = new ServerBootstrap();
b.group(group)
.channel(NioServerSocketChannel.class)
.localAddress(new InetSocketAddress(port))
.childHandler(new ChannelInitializer<SocketChannel>() {
#Override
public void initChannel(SocketChannel ch) throws Exception {
System.out.println("New client connected: " + ch.localAddress());
ch.pipeline().addLast(new EchoServerHandler());
}
});
ChannelFuture f = b.bind().sync();
f.channel().closeFuture().sync();
} finally {
group.shutdownGracefully().sync();
}
}
public static void main (String [] args) throws Exception {
new EchoServer(11235).start();
}
}
The server handler:
#Sharable
public class EchoServerHandler extends ChannelInboundHandlerAdapter {
public void channelRead(ChannelHandlerContext ctx, Object msg) {
ByteBuf in = (ByteBuf) msg;
System.out.println(
"Server received: " + in.toString(CharsetUtil.UTF_8));
ctx.write(in);
}
public void channelReadComplete(ChannelHandlerContext ctx) {
ctx.writeAndFlush(Unpooled.EMPTY_BUFFER)
.addListener(ChannelFutureListener.CLOSE);
}
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
cause.printStackTrace();
ctx.close();
}
}
It must be something small I'm missing, so any help will preserve my fleeting sanity and will be much appreciated!
Instead of write use writeAndFlush in your ClientHandler:
public void channelActive(ChannelHandlerContext ctx) {
System.out.println("Connected");
ctx.writeAndFlush(Unpooled.copiedBuffer("Netty MAY rock!", CharsetUtil.UTF_8));
}
I'm trying to listen for connections on two different ports
I start 2 Thread in a java main method,every Thread bind a port with netty4,but can't
listener success!
this is my code,the port 3333 is ok,but 1234 is not ok,it looks like 3333 is blocking!
public class ObjectServer
{
private static final Logger logger = LoggerFactory.getLogger(ObjectServer.class);
private String ip;
private int port;
public ObjectServer(int port)
{
this.port = port;
}
public void run(final ChannelInboundHandlerAdapter handler) throws Exception
{
EventLoopGroup bossGroup = new NioEventLoopGroup();
EventLoopGroup workerGroup = new NioEventLoopGroup();
try
{
ServerBootstrap server = new ServerBootstrap();
server.group(bossGroup, workerGroup).channel(NioServerSocketChannel.class).childHandler(new ChannelInitializer<SocketChannel>()
{
#Override
public void initChannel(SocketChannel ch) throws Exception
{
ch.pipeline().addLast(new ObjectEncoder(), new ObjectDecoder(ClassResolvers.cacheDisabled(null)), handler);
}
});
server.bind(port).sync().channel().closeFuture().sync();
}
catch (Exception e)
{
logger.error("开启监听失败！端口[" + port + "]", e);
throw e;
}
finally
{
bossGroup.shutdownGracefully();
workerGroup.shutdownGracefully();
}
}
}
public class SocketServer
{
private static final Logger logger = LoggerFactory.getLogger(SocketServer.class);
private static final StringDecoder DECODER = new StringDecoder();
private static final StringEncoder ENCODER = new StringEncoder();
private int port;
public SocketServer(int port)
{
this.port = port;
}
public void run(final ChannelInboundHandlerAdapter handler) throws Exception
{
EventLoopGroup bossGroup = new NioEventLoopGroup();
EventLoopGroup workerGroup = new NioEventLoopGroup();
try
{
ServerBootstrap b = new ServerBootstrap();
b.group(bossGroup, workerGroup).channel(NioServerSocketChannel.class).childHandler(new ChannelInitializer<SocketChannel>()
{
#Override
public void initChannel(SocketChannel ch) throws Exception
{
ChannelPipeline pipeline = ch.pipeline();
// Add the text line codec combination first,
pipeline.addLast("framer", new DelimiterBasedFrameDecoder(8192, Delimiters.lineDelimiter()));
// the encoder and decoder are static as these are
// sharable
pipeline.addLast("encoder", ENCODER);
pipeline.addLast("decoder", DECODER);
// and then business logic.
pipeline.addLast("handler", handler);
}
});
b.bind(port).sync().channel().closeFuture().sync();
}
catch (Exception e)
{
logger.error("开启监听失败！端口[" + port + "]", e);
throw e;
}
finally
{
bossGroup.shutdownGracefully();
workerGroup.shutdownGracefully();
}
}
}
public class Test
{
public static void main(String[] args) throws Exception
{
Thread1 thread1 = new Thread1();
Thread2 thread2 = new Thread2();
thread2.start();
thread1.start();
new SocketClient("192.168.16.52", 3333).run(new TestHandler4("test4"));
new ObjectClient("192.168.16.52", 1234).run(new TestHandler3("test3"));
}
#Sharable
static class TestHandler1 extends ChannelInboundHandlerAdapter
{
#Override
public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception
{
System.out.println("1234" + msg);
}
}
static class Thread1 extends Thread
{
#Override
public void run()
{
try
{
new ObjectServer(1234).run(new TestHandler1());
}
catch (Exception e)
{
e.printStackTrace();
}
}
}
static class Thread2 extends Thread
{
#Override
public void run()
{
try
{
new SocketServer(3333).run(new TestHandler2());
}
catch (Exception e)
{
e.printStackTrace();
}
}
}
#Sharable
static class TestHandler2 extends SimpleChannelInboundHandler<String>
{
#Override
public void channelRead0(ChannelHandlerContext ctx, String msg) throws Exception
{
System.out.println("3333" + msg);
}
#Override
public void channelActive(ChannelHandlerContext ctx) throws Exception
{
System.out.println("sssssssssssssssss");
}
}
#Sharable
static class TestHandler3 extends ChannelInboundHandlerAdapter
{
private String msg;
public TestHandler3(String msg)
{
this.msg = msg;
}
#Override
public void channelActive(ChannelHandlerContext ctx) throws Exception
{
ctx.writeAndFlush(msg);
}
}
#Sharable
static class TestHandler4 extends SimpleChannelInboundHandler<String>
{
private String msg;
public TestHandler4(String msg)
{
this.msg = msg;
}
#Override
public void channelActive(ChannelHandlerContext ctx) throws Exception
{
ctx.writeAndFlush(msg);
}
#Override
protected void channelRead0(ChannelHandlerContext arg0, String arg1)throws Exception
{
}
}
}
In your run() implementation, you do this:
server.bind(port).sync().channel().closeFuture().sync();
.. which will block until the server socket is closed. Because you do not close the server socket, it will never return. Therefore, only the first server socket will be bound.
What you probably want is just bind and return rather than waiting for the server sockets closed.
I am writing a netty client and server application that will write JVM GC stats to a time-series database to analyse for around 300 servers. However my pipeline is throwing lots of these exceptions:
10/02/2012 10:14:23.415 New I/O server worker #2-2 ERROR GCEventsCollector - netty error
java.io.StreamCorruptedException: invalid type code: 6E
at java.io.ObjectInputStream.readObject0(Unknown Source)
at java.io.ObjectInputStream.defaultReadFields(Unknown Source)
at java.io.ObjectInputStream.readSerialData(Unknown Source)
at java.io.ObjectInputStream.readOrdinaryObject(Unknown Source)
at java.io.ObjectInputStream.readObject0(Unknown Source)
at java.io.ObjectInputStream.readObject(Unknown Source)
at org.jboss.netty.handler.codec.serialization.ObjectDecoder.decode(ObjectDecoder.java:94)
at org.jboss.netty.handler.codec.frame.FrameDecoder.callDecode(FrameDecoder.java:282)
at org.jboss.netty.handler.codec.frame.FrameDecoder.messageReceived(FrameDecoder.java:216)
at org.jboss.netty.channel.Channels.fireMessageReceived(Channels.java:274)
at org.jboss.netty.channel.Channels.fireMessageReceived(Channels.java:261)
at org.jboss.netty.channel.socket.nio.NioWorker.read(NioWorker.java:349)
at org.jboss.netty.channel.socket.nio.NioWorker.processSelectedKeys(NioWorker.java:280)
at org.jboss.netty.channel.socket.nio.NioWorker.run(NioWorker.java:200)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
It looks like it's creating an OutputStream but one already exists - so it throws that specific exception. It appears in my AIT environment where >300 servers are connecting but not in DEV where 1 agent is only connecting.
I suspect it is either a bug in the object decoder or I have incorrect code somewhere. Please could anyone explain why this happens?
Here is the collector:
public class GCEventsCollector extends AbstractDataCollector {
protected static final Logger logger = Logger.getLogger(GCEventsCollector.class);
private static final ExecutorService WORKERS = Executors.newCachedThreadPool();
private static final ChannelGroup GROUP = new DefaultChannelGroup("gc-events");
private final int port;
private final ServerBootstrap bootstrap;
public GCEventsCollector(final int port) {
logger.info("Creating GC Events collector on port " + port);
this.port = port;
this.bootstrap = newServerBootstrap(port);
}
/**
* Creates a bootstrap for creating bindings to sockets. Each channel has a pipeline, which contains the
* logic for handling a message such as encoding, decoding, buffering, etc.
*
* #param port port of socket
* #return configured bootstrap
*/
private ServerBootstrap newServerBootstrap(int port) {
ExecutorService bossExecutor = Executors.newCachedThreadPool();
ExecutorService workerExecutor = Executors.newCachedThreadPool();
NioServerSocketChannelFactory channelFactory =
new NioServerSocketChannelFactory(bossExecutor, workerExecutor);
ServerBootstrap bootstrap = new ServerBootstrap(channelFactory);
ChannelHandler collectorHandler = new CollectorHandler();
bootstrap.setPipelineFactory(new CollectorPipelineFactory(collectorHandler));
bootstrap.setOption("localAddress", new InetSocketAddress(port));
return bootstrap;
}
protected KDBCategory[] getKDBCategories() {
return new KDBCategory[] { KDBCategory.GC_EVENTS };
}
/**
* Bind to a socket to accept messages
*
* #throws Exception
*/
public void doStart() throws Exception {
Channel channel = bootstrap.bind();
GROUP.add(channel);
}
/**
* Disconnect the channel to stop accepting messages and wait until disconnected
*
* #throws Exception
*/
public void doStop() throws Exception {
logger.info("disconnecting");
GROUP.close().awaitUninterruptibly();
}
class CollectorHandler extends SimpleChannelHandler {
#Override
public void channelOpen(ChannelHandlerContext ctx, ChannelStateEvent e)
throws Exception {
super.channelOpen(ctx, e);
GROUP.add(e.getChannel());
}
#Override
public void channelConnected(ChannelHandlerContext ctx,
ChannelStateEvent e) throws Exception {
super.channelConnected(ctx, e);
logger.info("channel connected");
}
#Override
public void channelDisconnected(ChannelHandlerContext ctx,
ChannelStateEvent e) throws Exception {
super.channelDisconnected(ctx, e);
logger.info("channel disconnected");
}
#Override
public void messageReceived(ChannelHandlerContext ctx, final MessageEvent e) throws Exception {
if (logger.isDebugEnabled()) {
logger.debug("Received GcStats event: " + e.toString());
}
WORKERS.execute(new Runnable() {
public void run() {
saveData(KDBCategory.GC_EVENTS, (GcEventsPersister) e.getMessage());
}
});
}
#Override
public void exceptionCaught(ChannelHandlerContext ctx, ExceptionEvent e) throws Exception {
logger.error("netty error", e.getCause());
}
}
private static class CollectorPipelineFactory implements ChannelPipelineFactory {
private final ChannelHandler handler;
private CollectorPipelineFactory(ChannelHandler handler) {
this.handler = handler;
}
#Override
public ChannelPipeline getPipeline() throws Exception {
return Channels.pipeline(new ObjectDecoder(), handler);
}
}
}
Here is the agent:
public class GCEventsAgent {
private final static Logger logger = Logger.getLogger(GCEventsAgent.class);
private static final ExecutorService bosses = Executors.newCachedThreadPool();
private static final ExecutorService workers = Executors.newCachedThreadPool();
private static final Timer timer = new HashedWheelTimer();
private static final String localHostName;
private static final ParseExceptionListener exceptionListener = new ExceptionListener();
static {
String name = "";
try {
name = InetAddress.getLocalHost().getHostName();
} catch (UnknownHostException e) {
logger.error("cannot retrieve local host name", e);
}
localHostName = name;
}
public static void main(final String[] args) {
checkArgument(args.length >= 3, "Usage: GCEventsAgent [log4j cfg] [mba cfg] [server cfg] [process 1] ... [process n]");
System.setProperty("log4j.configuration", "file:log4j.properties");
final String log4jConfig = args[0];
DOMConfigurator.configure(log4jConfig);
final String mbaConfig = args[1];
final String serverConfigPath = args[2];
final ServerConfig serverCfg = new ServerConfig(serverConfigPath);
setup(serverCfg, args);
}
private static void setup(ServerConfig cfg, String[] args) {
final String host = cfg.getParameter(String.class, "host");
final int port = cfg.getParameter(Integer.class, "port");
if (args.length == 3)
configurePolling(cfg, host, port);
else
configureProcesses(cfg, args, host, port);
}
private static void configureProcesses(final ServerConfig cfg,
final String[] args,
final String host,
final int port) {
final List<File> logFiles = logFiles(cfg, args);
logger.info("Initializing GC Agent for [" + host + ":" + port + "]");
final NioClientSocketChannelFactory channelFactory =
new NioClientSocketChannelFactory(bosses, workers);
final ClientBootstrap bootstrap = new ClientBootstrap(channelFactory);
bootstrap.setOption("remoteAddress", new InetSocketAddress(host, port));
final GCParserFactory parserFactory = new DefaultParserFactory();
final AgentProcessHandler agentHandler =
new AgentProcessHandler(bootstrap, logFiles, parserFactory);
bootstrap.setPipelineFactory(new ChannelPipelineFactory() {
#Override
public ChannelPipeline getPipeline() throws Exception {
return Channels.pipeline(new ObjectEncoder(), agentHandler);
}
});
bootstrap.connect().awaitUninterruptibly();
}
private static void configurePolling(ServerConfig cfg, String host, int port) {
final int frequency = cfg.getParameter(Integer.class, "frequency");
final NioClientSocketChannelFactory channelFactory =
new NioClientSocketChannelFactory(newCachedThreadPool(), newCachedThreadPool());
final ClientBootstrap bootstrap = new ClientBootstrap(channelFactory);
bootstrap.setOption("remoteAddress", new InetSocketAddress(host, port));
final GcParserSupplier parserSupplier = new GcParserSupplier();
final ConcurrentMap<File, Tailer> tailerMap = Maps.newConcurrentMap();
final ParseExceptionListener exceptionListener = new ExceptionListener();
final Set<File> discoveredSet = Sets.newHashSet();
final File directory = new File(cfg.getParameter(String.class, "logDirectory"));
final TailManager tailManager =
new TailManager(discoveredSet, tailerMap, parserSupplier, exceptionListener, localHostName);
final DetectionTask detectionTask = new DetectionTask(directory, discoveredSet, tailManager);
final FileWatcher fileWatcher =
new FileWatcher(Executors.newScheduledThreadPool(1), detectionTask, frequency);
final Timer timer = new HashedWheelTimer();
final EfxAgentHandler agentHandler =
new EfxAgentHandler(bootstrap, tailManager, fileWatcher, timer);
bootstrap.setPipelineFactory(new ChannelPipelineFactory() {
#Override public ChannelPipeline getPipeline() throws Exception {
return Channels.pipeline(new ObjectEncoder(), agentHandler);
}
});
bootstrap.connect().awaitUninterruptibly();
}
private static List<File> logFiles(ServerConfig cfg, String[] args) {
String logDir = cfg.getParameter(String.class, "logDirectory");
final int n = args.length;
List<File> logFiles = new ArrayList<File>(n-3);
for (int i = 3; i < n; i++) {
String filePath = logDir + args[i] + ".gc.log";
try {
File file = new File(filePath);
if (!file.exists()) {
logger.info("missing log file so creating empty file at path: " + filePath);
File dir = file.getParentFile();
dir.mkdirs();
if (file.createNewFile())
logger.info("successfully created empty file at path: " + filePath);
}
logFiles.add(file);
} catch (IOException e) {
logger.error("error creating log file at path: " + filePath);
}
}
return logFiles;
}
static final class AgentPauseListener implements GCEventListener<CMSType, CMSHeap> {
private final Channel channel;
private final GcEventsPersister.Builder builder;
private byte state;
private AgentPauseListener(Channel channel,
GcEventsPersister.Builder builder) {
this.channel = channel;
this.builder = builder;
}
#Override
public void onPause(PauseDetail<CMSType> pauseDetail) {
logger.info("onPause");
checkState(state == 0x00 || state == 0x01);
builder
.collectionType(pauseDetail.getType() == null
? null : pauseDetail.getType().toString())
.start(new Instant(pauseDetail.getStartTimestamp()))
.end(new Instant(pauseDetail.getEndTimestamp()))
.pause(pauseDetail.getType() == null
? false : pauseDetail.getType().isPause())
.duration(pauseDetail.getPauseMillis());
if (state == 0x00)
channel.write(builder.build());
else
state |= 0x02;
}
#Override
public void onHeapBefore(HeapDetail<CMSHeap> details) {
logger.info("onHeapBefore");
checkState(state == 0x00);
builder.heapBefore(used(details)).heapBeforeTotal(total(details));
state |= 0x01;
}
#Override
public void onHeapAfter(HeapDetail<CMSHeap> details) {
logger.info("onHeapAfter");
checkState(state == 0x03);
builder.heapAfter(used(details)).heapAfterTotal(total(details));
channel.write(builder.build());
state = 0x00;
}
private final long used(HeapDetail<CMSHeap> details) {
return used(details, CMSHeap.PAR_NEW_GENERATION)
+ used(details, CMSHeap.CMS_GENERATION)
+ used(details, CMSHeap.CMS_PERM_GENERATION);
}
private final long used(HeapDetail<CMSHeap> heapDetail,
CMSHeap gen) {
final Map<CMSHeap, HeapDetail.HeapMetric> sizes = heapDetail.getSizes();
final long used = sizes.get(gen).getUsed();
logger.info("used = " + used);
return used;
}
private final long total(HeapDetail<CMSHeap> details) {
return total(details, CMSHeap.PAR_NEW_GENERATION)
+ total(details, CMSHeap.CMS_GENERATION)
+ total(details, CMSHeap.CMS_PERM_GENERATION);
}
private final long total(HeapDetail<CMSHeap> heapDetail,
CMSHeap gen) {
final Map<CMSHeap, HeapDetail.HeapMetric> sizes = heapDetail.getSizes();
return sizes.get(gen).getTotal();
}
}
static final class ExceptionListener implements ParseExceptionListener {
#Override
public void onParseError(int lineNo, String input, String error) {
logger.error("error parsing: " + lineNo + " - " + input + " - " + error);
}
}
static final class ReconnectTask implements TimerTask {
private final ClientBootstrap bootstrap;
ReconnectTask(ClientBootstrap bootstrap) {
this.bootstrap = bootstrap;
}
#Override
public void run(Timeout timeout) throws Exception {
bootstrap.connect();
}
}
static class AgentProcessHandler extends SimpleChannelHandler {
private final ClientBootstrap bootstrap;
private final List<File> logFiles;
private final GCParserFactory parserFactory;
private final Set<Tailer> tailers = new HashSet<Tailer>(4);
public AgentProcessHandler(ClientBootstrap bootstrap,
List<File> logFiles,
GCParserFactory parserFactory) {
this.bootstrap = bootstrap;
this.logFiles = logFiles;
this.parserFactory = parserFactory;
}
#Override
public void channelConnected(ChannelHandlerContext ctx, ChannelStateEvent e)
throws Exception {
logger.info("channel connected");
for (File logFile : logFiles) {
logger.info("setting up scraper for logfile: " + logFile);
GCParser parser = parserFactory.getParser();
GcEventsPersister.Builder builder =
new GcEventsPersister.Builder(logFile.getName(), localHostName);
GCEventListener gcEventListener =
new AgentPauseListener(e.getChannel(), builder);
TailerListener listener =
new LogLineListener(parser, gcEventListener, exceptionListener);
Tailer tailer = Tailer.create(logFile, listener, 1000L, true);
tailers.add(tailer);
}
}
#Override
public void channelDisconnected(ChannelHandlerContext ctx, ChannelStateEvent e)
throws Exception {
logger.error("channel disconnected");
stopTailers();
scheduleReconnect();
}
private void scheduleReconnect() {
timer.newTimeout(new ReconnectTask(bootstrap), 5L, TimeUnit.SECONDS);
}
private final void stopTailers() {
for (Tailer tailer : tailers) {
tailer.stop();
}
tailers.clear();
}
#Override
public void exceptionCaught(ChannelHandlerContext ctx, ExceptionEvent e)
throws Exception {
final Throwable cause = e.getCause();
logger.error(cause);
if (cause instanceof ConnectException) {
stopTailers();
scheduleReconnect();
}
}
};
private static class LogLineListener extends TailerListenerAdapter {
private final GCParser parser;
private final GCEventListener pauseListener;
private final ParseExceptionListener exceptionLister;
public LogLineListener(GCParser parser,
GCEventListener listener,
ParseExceptionListener exceptionLister) {
this.parser = parser;
this.pauseListener = listener;
this.exceptionLister = exceptionLister;
}
#Override
public void handle(String line) {
logger.info("handle(String line)");
parser.matchLine(line, pauseListener, exceptionLister);
}
}
private static final class GcParserSupplier
implements Supplier<GCParser<CMSType, CMSHeap>> {
#Override public GCParser<CMSType, CMSHeap> get() {
return new CMSParser();
}
}
private static final class TailManager implements FileHandler {
private final Set<File> discoveredSet;
private final ConcurrentMap<File, Tailer> tailerMap;
private final Supplier<GCParser<CMSType, CMSHeap>> parserSupplier;
private final ParseExceptionListener exceptionListener;
private final String host;
private volatile boolean go;
private TailManager(final Set<File> discoveredSet,
final ConcurrentMap<File, Tailer> tailerMap,
final Supplier<GCParser<CMSType, CMSHeap>> parserSupplier,
final ParseExceptionListener exceptionListener,
final String host) {
this.discoveredSet = discoveredSet;
this.tailerMap = tailerMap;
this.parserSupplier = parserSupplier;
this.exceptionListener = exceptionListener;
this.host = host;
}
public void stop() {
go = false;
for (Tailer tailer : tailerMap.values())
tailer.stop();
tailerMap.clear();
}
public void start() {
go = true;
}
#Override public void onNew(final File file,
final Channel channel) {
checkState(go);
GCParser<CMSType, CMSHeap> parser = parserSupplier.get();
String fileName = file.getName();
GcEventsPersister.Builder builder =
new GcEventsPersister.Builder(fileName, host);
AgentPauseListener eventListener =
new AgentPauseListener(channel, builder);
Function<Void, Void> removeTail = new Function<Void, Void>() {
#Override
public Void apply(#Nullable final Void input) {
final Tailer tailer = tailerMap.remove(file);
tailer.stop();
discoveredSet.remove(file);
return null;
}
};
GcTailAdaptor listener =
new GcTailAdaptor(logger, parser, eventListener, exceptionListener, removeTail);
tailerMap.put(file, Tailer.create(file, listener, 1000L, true));
}
#Override public void onDelete(File file, Channel channel) {
checkState(go);
final Tailer tailer = tailerMap.remove(file);
tailer.stop();
}
}
static class EfxAgentHandler extends SimpleChannelHandler {
private final ClientBootstrap bootstrap;
private final TailManager tailManager;
private final FileWatcher fileWatcher;
private final Timer timer;
public EfxAgentHandler(ClientBootstrap bootstrap,
TailManager tailManager,
FileWatcher fileWatcher,
Timer timer) {
this.bootstrap = bootstrap;
this.tailManager = tailManager;
this.fileWatcher = fileWatcher;
this.timer = timer;
}
#Override public void channelConnected(ChannelHandlerContext ctx,
ChannelStateEvent e) throws Exception {
logger.info("channel connected");
tailManager.start();
fileWatcher.start(e.getChannel());
}
#Override public void channelDisconnected(ChannelHandlerContext ctx,
ChannelStateEvent e) throws Exception {
logger.error("channel disconnected");
tailManager.stop();
fileWatcher.stop();
scheduleReconnect();
}
private void scheduleReconnect() {
timer.newTimeout(new ReconnectTask(bootstrap), 5L, TimeUnit.SECONDS);
}
#Override public void exceptionCaught(ChannelHandlerContext ctx,
ExceptionEvent e) throws Exception {
final Throwable cause = e.getCause();
logger.error(cause);
if (cause instanceof ConnectException) {
tailManager.stop();
scheduleReconnect();
}
}
}
static final class GcTailAdaptor extends TailerListenerAdapter {
private final Logger logger;
private final GCParser parser;
private final GCEventListener eventListener;
private final ParseExceptionListener exceptionListener;
private final Function<Void, Void> removeTail;
private volatile long lastTail;
GcTailAdaptor(final Logger logger,
final GCParser parser,
final GCEventListener eventListener,
final ParseExceptionListener exceptionListener,
final Function<Void, Void> removeTail) {
this.logger = logger;
this.parser = parser;
this.eventListener = eventListener;
this.exceptionListener = exceptionListener;
this.removeTail = removeTail;
}
#Override public void handle(String line) {
lastTail();
parser.matchLine(line, eventListener, exceptionListener);
}
private final void lastTail() {
final long t = System.currentTimeMillis();
if (lastTail == 0L) {
lastTail = t;
return;
}
if ((t-lastTail)>=1800000L)
removeTail.apply(null);
}
#Override public void handle(Exception ex) {
logger.error(ex);
}
}
#VisibleForTesting
final static class DetectionTask implements Runnable {
private final File directory;
private final Set<File> discovered;
private final FileHandler handler;
private volatile Channel channel;
DetectionTask(final File directory,
final Set<File> discovered,
final FileHandler handler) {
this.discovered = discovered;
this.handler = handler;
this.directory = directory;
}
public void setChannel(Channel channel) {
this.channel = channel;
}
public boolean removeStaleFile(File file) {
checkArgument(discovered.contains(file),
"file is not discovered so cannot be stale");
return discovered.remove(file);
}
public void run() {
final File[] files = directory.listFiles();
for (int i=0, n=files.length; i<n; i++) {
final File file = files[i];
synchronized (discovered) {
if (!discovered.contains(file)) {
discovered.add(file);
handler.onNew(file, channel);
}
}
}
final ImmutableSet<File> logFiles = ImmutableSet.copyOf(files);
final ImmutableSet<File> diff = Sets.difference(discovered, logFiles).immutableCopy();
for (File file : diff) {
discovered.remove(file);
handler.onDelete(file, channel);
}
}
}
#VisibleForTesting static interface FileHandler {
void onNew(File file, Channel channel);
void onDelete(File file, Channel channel);
}
#VisibleForTesting
final static class FileWatcher {
private final ScheduledExecutorService executor;
private final DetectionTask detectionTask;
private final int frequency;
private volatile ScheduledFuture<?> task;
#VisibleForTesting
FileWatcher(ScheduledExecutorService executor,
DetectionTask detectionTask,
int frequency) {
this.executor = executor;
this.detectionTask = detectionTask;
this.frequency = frequency;
}
public void start(Channel chanel) {
task = executor.scheduleAtFixedRate(detectionTask, 0L, frequency, TimeUnit.SECONDS);
detectionTask.setChannel(chanel);
}
public void stop() {
task.cancel(true);
detectionTask.setChannel(null);
}
public static FileWatcher on(File directory,
FileHandler handler,
int frequency) {
checkNotNull(directory);
checkNotNull(handler);
checkArgument(directory.isDirectory(), "file is not a directory");
checkArgument(directory.canRead(), "no read access to directory");
checkArgument(0 < frequency, "frequency must be > 0");
final HashSet<File> objects = Sets.newHashSet();
final DetectionTask task = new DetectionTask(directory, objects, handler);
final ScheduledExecutorService executorService = Executors.newScheduledThreadPool(1);
return new FileWatcher(executorService, task, frequency);
}
}
}
I have incorrect code somewhere.
Correct. Specifically, you almost certainly have different ObjectInput/OutputStream lifetimes at server and client. Use the same streams for the life of the socket, and don't do any I/O over those sockets via any other means.
I discovered why this happens. I am using a deprecated ObjectDecoder that's not compatible with my client's ObjectEncoder. I am just sending a ByteBuffer instead and it's fine now.