NettyServerHandler -> AbstractServer -> AbstractPeer -> AbstractChannelHandlerDelegate -> HeartbeatHandler -> AllChannelHandler
-> ChannelEventRunnable -> HeaderExchangeHandler -> DubboProtocol.ExchangeHandlerAdapter
NettyServerHandler.channelActive
public void channelActive(ChannelHandlerContext ctx) throws Exception {
ctx.fireChannelActive();
NettyChannel channel = NettyChannel.getOrAddChannel(ctx.channel(), url, handler);
try {
if (channel != null) {
channels.put(NetUtils.toAddressString((InetSocketAddress) ctx.channel().remoteAddress()), channel);
}
handler.connected(channel);
} finally {
NettyChannel.removeChannelIfDisconnected(ctx.channel());
}
}
AbstractServer
public void connected(Channel ch) throws RemotingException {
// If the server has entered the shutdown process, reject any new connection
if (this.isClosing() || this.isClosed()) {
logger.warn("Close new channel " + ch + ", cause: server is closing or has been closed. For example, receive a new connect request while in shutdown process.");
ch.close();
return;
}
Collection<Channel> channels = getChannels();
if (accepts > 0 && channels.size() > accepts) {
logger.error("Close channel " + ch + ", cause: The server " + ch.getLocalAddress() + " connections greater than max config " + accepts);
ch.close();
return;
}
super.connected(ch);
}
AbstractPeer
@Override
public void connected(Channel ch) throws RemotingException {
if (closed) {
return;
}
handler.connected(ch);
}
AbstractChannelHandlerDelegate
@Override
public void connected(Channel channel) throws RemotingException {
handler.connected(channel);
}
HeartbeatHandler
@Override
public void connected(Channel channel) throws RemotingException {
setReadTimestamp(channel);
setWriteTimestamp(channel);
handler.connected(channel);
}
AllChannelHandler
@Override
public void connected(Channel channel) throws RemotingException {
ExecutorService cexecutor = getExecutorService();
try {
cexecutor.execute(new ChannelEventRunnable(channel, handler, ChannelState.CONNECTED));
} catch (Throwable t) {
throw new ExecutionException("connect event", channel, getClass() + " error when process connected event .", t);
}
}
ChannelEventRunnable
@Override
public void run() {
if (state == ChannelState.RECEIVED) {
try {
handler.received(channel, message);
} catch (Exception e) {
logger.warn("ChannelEventRunnable handle " + state + " operation error, channel is " + channel
+ ", message is " + message, e);
}
} else {
switch (state) {
case CONNECTED:
try {
handler.connected(channel);
} catch (Exception e) {
logger.warn("ChannelEventRunnable handle " + state + " operation error, channel is " + channel, e);
}
break;
case DISCONNECTED:
try {
handler.disconnected(channel);
} catch (Exception e) {
logger.warn("ChannelEventRunnable handle " + state + " operation error, channel is " + channel, e);
}
break;
case SENT:
try {
handler.sent(channel, message);
} catch (Exception e) {
logger.warn("ChannelEventRunnable handle " + state + " operation error, channel is " + channel
+ ", message is " + message, e);
}
case CAUGHT:
try {
handler.caught(channel, exception);
} catch (Exception e) {
logger.warn("ChannelEventRunnable handle " + state + " operation error, channel is " + channel
+ ", message is: " + message + ", exception is " + exception, e);
}
break;
default:
logger.warn("unknown state: " + state + ", message is " + message);
}
}
}
AbstractChannelHandlerDelegate
@Override
public void connected(Channel channel) throws RemotingException {
handler.connected(channel);
}
HeaderExchangeHandler
@Override
public void connected(Channel channel) throws RemotingException {
channel.setAttribute(KEY_READ_TIMESTAMP, System.currentTimeMillis());
channel.setAttribute(KEY_WRITE_TIMESTAMP, System.currentTimeMillis());
ExchangeChannel exchangeChannel = HeaderExchangeChannel.getOrAddChannel(channel);
try {
handler.connected(exchangeChannel);
} finally {
HeaderExchangeChannel.removeChannelIfDisconnected(channel);
}
}
DubboProtocol.ExchangeHandlerAdapter
@Override
public void connected(Channel channel) throws RemotingException {
invoke(channel, Constants.ON_CONNECT_KEY);
}
private void invoke(Channel channel, String methodKey) {
Invocation invocation = createInvocation(channel, channel.getUrl(), methodKey);
if (invocation != null) {
try {
received(channel, invocation);
} catch (Throwable t) {
logger.warn("Failed to invoke event method " + invocation.getMethodName() + "(), cause: " + t.getMessage(), t);
}
}
}
private Invocation createInvocation(Channel channel, URL url, String methodKey) {
String method = url.getParameter(methodKey);
if (method == null || method.length() == 0) {
return null;
}
RpcInvocation invocation = new RpcInvocation(method, new Class<?>[0], new Object[0]);
invocation.setAttachment(Constants.PATH_KEY, url.getPath());
invocation.setAttachment(Constants.GROUP_KEY, url.getParameter(Constants.GROUP_KEY));
invocation.setAttachment(Constants.INTERFACE_KEY, url.getParameter(Constants.INTERFACE_KEY));
invocation.setAttachment(Constants.VERSION_KEY, url.getParameter(Constants.VERSION_KEY));
if (url.getParameter(Constants.STUB_EVENT_KEY, false)) {
invocation.setAttachment(Constants.STUB_EVENT_KEY, Boolean.TRUE.toString());
}
return invocation;
}
NettyServerHandler -> AbstractPeer -> MultiMessageHandler -> HeartbeatHandler -> AllChannelHandler
-> ChannelEventRunnable -> DecodeHandler -> DubboProtocol.ExchangeHandlerAdapter -> DecodeableRpcInvocation -> HeaderExchangeHandler
NettyServerHandler.channelRead()
@Override
public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
NettyChannel channel = NettyChannel.getOrAddChannel(ctx.channel(), url, handler);
try {
handler.received(channel, msg);
} finally {
NettyChannel.removeChannelIfDisconnected(ctx.channel());
}
}
AbstractPeer.received()
@Override
public void received(Channel ch, Object msg) throws RemotingException {
if (closed) {
return;
}
handler.received(ch, msg);
}
MultiMessageHandler.received()
public void received(Channel channel, Object message) throws RemotingException {
if (message instanceof MultiMessage) {
MultiMessage list = (MultiMessage) message;
for (Object obj : list) {
handler.received(channel, obj);
}
} else {
handler.received(channel, message);
}
}
HeartbeatHandler.received()
@Override
public void received(Channel channel, Object message) throws RemotingException {
setReadTimestamp(channel);
if (isHeartbeatRequest(message)) {
Request req = (Request) message;
if (req.isTwoWay()) {
Response res = new Response(req.getId(), req.getVersion());
res.setEvent(Response.HEARTBEAT_EVENT);
channel.send(res);
if (logger.isInfoEnabled()) {
int heartbeat = channel.getUrl().getParameter(Constants.HEARTBEAT_KEY, 0);
if (logger.isDebugEnabled()) {
logger.debug("Received heartbeat from remote channel " + channel.getRemoteAddress()
+ ", cause: The channel has no data-transmission exceeds a heartbeat period"
+ (heartbeat > 0 ? ": " + heartbeat + "ms" : ""));
}
}
}
return;
}
if (isHeartbeatResponse(message)) {
if (logger.isDebugEnabled()) {
logger.debug("Receive heartbeat response in thread " + Thread.currentThread().getName());
}
return;
}
handler.received(channel, message);
}
AllChannelHandler.received()
@Override
public void received(Channel channel, Object message) throws RemotingException {
ExecutorService cexecutor = getExecutorService();
try {
cexecutor.execute(new ChannelEventRunnable(channel, handler, ChannelState.RECEIVED, message));
} catch (Throwable t) {
//TODO A temporary solution to the problem that the exception information can not be sent to the opposite end after the thread pool is full. Need a refactoring
//fix The thread pool is full, refuses to call, does not return, and causes the consumer to wait for time out
if(message instanceof Request && t instanceof RejectedExecutionException){
Request request = (Request)message;
if(request.isTwoWay()){
String msg = "Server side(" + url.getIp() + "," + url.getPort() + ") threadpool is exhausted ,detail msg:" + t.getMessage();
Response response = new Response(request.getId(), request.getVersion());
response.setStatus(Response.SERVER_THREADPOOL_EXHAUSTED_ERROR);
response.setErrorMessage(msg);
channel.send(response);
return;
}
}
throw new ExecutionException(message, channel, getClass() + " error when process received event .", t);
}
}
ChannelEventRunnable
@Override
public void run() {
if (state == ChannelState.RECEIVED) {
try {
handler.received(channel, message);
} catch (Exception e) {
logger.warn("ChannelEventRunnable handle " + state + " operation error, channel is " + channel
+ ", message is " + message, e);
}
DecodeHandler.received()
@Override
public void received(Channel channel, Object message) throws RemotingException {
if (message instanceof Decodeable) {
decode(message);
}
if (message instanceof Request) {
decode(((Request) message).getData());
}
if (message instanceof Response) {
decode(((Response) message).getResult());
}
handler.received(channel, message);
}
DecodeHandler.decode()
private void decode(Object message) {
if (message != null && message instanceof Decodeable) {
try {
((Decodeable) message).decode();
if (log.isDebugEnabled()) {
log.debug("Decode decodeable message " + message.getClass().getName());
}
} catch (Throwable e) {
if (log.isWarnEnabled()) {
log.warn("Call Decodeable.decode failed: " + e.getMessage(), e);
}
} // ~ end of catch
} // ~ end of if
} // ~ end of method decode
DecodeableRpcInvocation.decode()
@Override
public void decode() throws Exception {
if (!hasDecoded && channel != null && inputStream != null) {
try {
decode(channel, inputStream);
} catch (Throwable e) {
if (log.isWarnEnabled()) {
log.warn("Decode rpc invocation failed: " + e.getMessage(), e);
}
request.setBroken(true);
request.setData(e);
} finally {
hasDecoded = true;
}
}
}
HeaderExchangeHandler.received() 接上面DecodeHandler.receive()
@Override
public void received(Channel channel, Object message) throws RemotingException {
channel.setAttribute(KEY_READ_TIMESTAMP, System.currentTimeMillis());
ExchangeChannel exchangeChannel = HeaderExchangeChannel.getOrAddChannel(channel);
try {
if (message instanceof Request) {
// handle request.
Request request = (Request) message;
if (request.isEvent()) {
handlerEvent(channel, request);
} else {
if (request.isTwoWay()) {
Response response = handleRequest(exchangeChannel, request);
channel.send(response);
} else {
handler.received(exchangeChannel, request.getData());
}
}
} else if (message instanceof Response) {
handleResponse(channel, (Response) message);
} else if (message instanceof String) {
if (isClientSide(channel)) {
Exception e = new Exception("Dubbo client can not supported string message: " + message + " in channel: " + channel + ", url: " + channel.getUrl());
logger.error(e.getMessage(), e);
} else {
String echo = handler.telnet(channel, (String) message);
if (echo != null && echo.length() > 0) {
channel.send(echo);
}
}
} else {
handler.received(exchangeChannel, message);
}
} finally {
HeaderExchangeChannel.removeChannelIfDisconnected(channel);
}
}
Response handleRequest(ExchangeChannel channel, Request req) throws RemotingException {
Response res = new Response(req.getId(), req.getVersion());
if (req.isBroken()) {
Object data = req.getData();
String msg;
if (data == null) msg = null;
else if (data instanceof Throwable) msg = StringUtils.toString((Throwable) data);
else msg = data.toString();
res.setErrorMessage("Fail to decode request due to: " + msg);
res.setStatus(Response.BAD_REQUEST);
return res;
}
// find handler by message class.
Object msg = req.getData();
try {
// handle data.
Object result = handler.reply(channel, msg);
res.setStatus(Response.OK);
res.setResult(result);
} catch (Throwable e) {
res.setStatus(Response.SERVICE_ERROR);
res.setErrorMessage(StringUtils.toString(e));
}
return res;
}
DubboProtocol.ExchangeHandler
@Override
public Object reply(ExchangeChannel channel, Object message) throws RemotingException {
if (message instanceof Invocation) {
Invocation inv = (Invocation) message;
Invoker<?> invoker = getInvoker(channel, inv);
// need to consider backward-compatibility if it's a callback
if (Boolean.TRUE.toString().equals(inv.getAttachments().get(IS_CALLBACK_SERVICE_INVOKE))) {
String methodsStr = invoker.getUrl().getParameters().get("methods");
boolean hasMethod = false;
if (methodsStr == null || methodsStr.indexOf(",") == -1) {
hasMethod = inv.getMethodName().equals(methodsStr);
} else {
String[] methods = methodsStr.split(",");
for (String method : methods) {
if (inv.getMethodName().equals(method)) {
hasMethod = true;
break;
}
}
}
if (!hasMethod) {
logger.warn(new IllegalStateException("The methodName " + inv.getMethodName()
+ " not found in callback service interface ,invoke will be ignored."
+ " please update the api interface. url is:"
+ invoker.getUrl()) + " ,invocation is :" + inv);
return null;
}
}
RpcContext.getContext().setRemoteAddress(channel.getRemoteAddress());
return invoker.invoke(inv);
}
throw new RemotingException(channel, "Unsupported request: "
+ (message == null ? null : (message.getClass().getName() + ": " + message))
+ ", channel: consumer: " + channel.getRemoteAddress() + " --> provider: " + channel.getLocalAddress());
}
Invoker<?> getInvoker(Channel channel, Invocation inv) throws RemotingException {
boolean isCallBackServiceInvoke = false;
boolean isStubServiceInvoke = false;
int port = channel.getLocalAddress().getPort();
String path = inv.getAttachments().get(Constants.PATH_KEY);
// if it's callback service on client side
isStubServiceInvoke = Boolean.TRUE.toString().equals(inv.getAttachments().get(Constants.STUB_EVENT_KEY));
if (isStubServiceInvoke) {
port = channel.getRemoteAddress().getPort();
}
//callback
isCallBackServiceInvoke = isClientSide(channel) && !isStubServiceInvoke;
if (isCallBackServiceInvoke) {
path = inv.getAttachments().get(Constants.PATH_KEY) + "." + inv.getAttachments().get(Constants.CALLBACK_SERVICE_KEY);
inv.getAttachments().put(IS_CALLBACK_SERVICE_INVOKE, Boolean.TRUE.toString());
}
String serviceKey = serviceKey(port, path, inv.getAttachments().get(Constants.VERSION_KEY), inv.getAttachments().get(Constants.GROUP_KEY));
DubboExporter<?> exporter = (DubboExporter<?>) exporterMap.get(serviceKey);
if (exporter == null)
throw new RemotingException(channel, "Not found exported service: " + serviceKey + " in " + exporterMap.keySet() + ", may be version or group mismatch " + ", channel: consumer: " + channel.getRemoteAddress() + " --> provider: " + channel.getLocalAddress() + ", message:" + inv);
return exporter.getInvoker();
}
AbstractPeer
由HeaderExchangeHandler.received调用send()方法
@Override
public void send(Object message) throws RemotingException {
send(message, url.getParameter(Constants.SENT_KEY, false));
}
NettyChannel
@Override
public void send(Object message, boolean sent) throws RemotingException {
super.send(message, sent);
boolean success = true;
int timeout = 0;
try {
ChannelFuture future = channel.writeAndFlush(message);
if (sent) {
timeout = getUrl().getPositiveParameter(Constants.TIMEOUT_KEY, Constants.DEFAULT_TIMEOUT);
success = future.await(timeout);
}
Throwable cause = future.cause();
if (cause != null) {
throw cause;
}
} catch (Throwable e) {
throw new RemotingException(this, "Failed to send message " + message + " to " + getRemoteAddress() + ", cause: " + e.getMessage(), e);
}
if (!success) {
throw new RemotingException(this, "Failed to send message " + message + " to " + getRemoteAddress()
+ "in timeout(" + timeout + "ms) limit");
}
}
AbstractChannel
@Override
public void send(Object message, boolean sent) throws RemotingException {
if (isClosed()) {
throw new RemotingException(this, "Failed to send message "
+ (message == null ? "" : message.getClass().getName()) + ":" + message
+ ", cause: Channel closed. channel: " + getLocalAddress() + " -> " + getRemoteAddress());
}
}
InternalDecoder
@Override
protected void decode(ChannelHandlerContext ctx, ByteBuf input, List<Object> out) throws Exception {
ChannelBuffer message = new NettyBackedChannelBuffer(input);
NettyChannel channel = NettyChannel.getOrAddChannel(ctx.channel(), url, handler);
Object msg;
int saveReaderIndex;
try {
// decode object.
do {
saveReaderIndex = message.readerIndex();
try {
msg = codec.decode(channel, message);
} catch (IOException e) {
throw e;
}
if (msg == Codec2.DecodeResult.NEED_MORE_INPUT) {
message.readerIndex(saveReaderIndex);
break;
} else {
//is it possible to go here ?
if (saveReaderIndex == message.readerIndex()) {
throw new IOException("Decode without read data.");
}
if (msg != null) {
out.add(msg);
}
}
} while (message.readable());
} finally {
NettyChannel.removeChannelIfDisconnected(ctx.channel());
}
}
}
DubboCountCodec
@Override
public Object decode(Channel channel, ChannelBuffer buffer) throws IOException {
int save = buffer.readerIndex();
MultiMessage result = MultiMessage.create();
do {
Object obj = codec.decode(channel, buffer);
if (Codec2.DecodeResult.NEED_MORE_INPUT == obj) {
buffer.readerIndex(save);
break;
} else {
result.addMessage(obj);
logMessageLength(obj, buffer.readerIndex() - save);
save = buffer.readerIndex();
}
} while (true);
if (result.isEmpty()) {
return Codec2.DecodeResult.NEED_MORE_INPUT;
}
if (result.size() == 1) {
return result.get(0);
}
return result;
}
ExchangeCodec
@Override
public Object decode(Channel channel, ChannelBuffer buffer) throws IOException {
int readable = buffer.readableBytes();
byte[] header = new byte[Math.min(readable, HEADER_LENGTH)];
buffer.readBytes(header);
return decode(channel, buffer, readable, header);
}
@Override
protected Object decode(Channel channel, ChannelBuffer buffer, int readable, byte[] header) throws IOException {
// check magic number.
if (readable > 0 && header[0] != MAGIC_HIGH
|| readable > 1 && header[1] != MAGIC_LOW) {
int length = header.length;
if (header.length < readable) {
header = Bytes.copyOf(header, readable);
buffer.readBytes(header, length, readable - length);
}
for (int i = 1; i < header.length - 1; i++) {
if (header[i] == MAGIC_HIGH && header[i + 1] == MAGIC_LOW) {
buffer.readerIndex(buffer.readerIndex() - header.length + i);
header = Bytes.copyOf(header, i);
break;
}
}
return super.decode(channel, buffer, readable, header);
}
// check length.
if (readable < HEADER_LENGTH) {
return DecodeResult.NEED_MORE_INPUT;
}
// get data length.
int len = Bytes.bytes2int(header, 12);
checkPayload(channel, len);
int tt = len + HEADER_LENGTH;
if (readable < tt) {
return DecodeResult.NEED_MORE_INPUT;
}
// limit input stream.
ChannelBufferInputStream is = new ChannelBufferInputStream(buffer, len);
try {
return decodeBody(channel, is, header);
} finally {
if (is.available() > 0) {
try {
if (logger.isWarnEnabled()) {
logger.warn("Skip input stream " + is.available());
}
StreamUtils.skipUnusedStream(is);
} catch (IOException e) {
logger.warn(e.getMessage(), e);
}
}
}
}
@Override
protected Object decodeBody(Channel channel, InputStream is, byte[] header) throws IOException {
byte flag = header[2], proto = (byte) (flag & SERIALIZATION_MASK);
// get request id.
long id = Bytes.bytes2long(header, 4);
if ((flag & FLAG_REQUEST) == 0) {
// decode response.
Response res = new Response(id);
if ((flag & FLAG_EVENT) != 0) {
res.setEvent(Response.HEARTBEAT_EVENT);
}
// get status.
byte status = header[3];
res.setStatus(status);
try {
ObjectInput in = CodecSupport.deserialize(channel.getUrl(), is, proto);
if (status == Response.OK) {
Object data;
if (res.isHeartbeat()) {
data = decodeHeartbeatData(channel, in);
} else if (res.isEvent()) {
data = decodeEventData(channel, in);
} else {
DecodeableRpcResult result;
if (channel.getUrl().getParameter(
Constants.DECODE_IN_IO_THREAD_KEY,
Constants.DEFAULT_DECODE_IN_IO_THREAD)) {
result = new DecodeableRpcResult(channel, res, is,
(Invocation) getRequestData(id), proto);
result.decode();
} else {
result = new DecodeableRpcResult(channel, res,
new UnsafeByteArrayInputStream(readMessageData(is)),
(Invocation) getRequestData(id), proto);
}
data = result;
}
res.setResult(data);
} else {
res.setErrorMessage(in.readUTF());
}
} catch (Throwable t) {
if (log.isWarnEnabled()) {
log.warn("Decode response failed: " + t.getMessage(), t);
}
res.setStatus(Response.CLIENT_ERROR);
res.setErrorMessage(StringUtils.toString(t));
}
return res;
} else {
// decode request.
Request req = new Request(id);
req.setVersion(Version.getProtocolVersion());
req.setTwoWay((flag & FLAG_TWOWAY) != 0);
if ((flag & FLAG_EVENT) != 0) {
req.setEvent(Request.HEARTBEAT_EVENT);
}
try {
Object data;
ObjectInput in = CodecSupport.deserialize(channel.getUrl(), is, proto);
if (req.isHeartbeat()) {
data = decodeHeartbeatData(channel, in);
} else if (req.isEvent()) {
data = decodeEventData(channel, in);
} else {
DecodeableRpcInvocation inv;
if (channel.getUrl().getParameter(
Constants.DECODE_IN_IO_THREAD_KEY,
Constants.DEFAULT_DECODE_IN_IO_THREAD)) {
inv = new DecodeableRpcInvocation(channel, req, is, proto);
inv.decode();
} else {
inv = new DecodeableRpcInvocation(channel, req,
new UnsafeByteArrayInputStream(readMessageData(is)), proto);
}
data = inv;
}
req.setData(data);
} catch (Throwable t) {
if (log.isWarnEnabled()) {
log.warn("Decode request failed: " + t.getMessage(), t);
}
// bad request
req.setBroken(true);
req.setData(t);
}
return req;
}
}
DecodeableRpcInvocation
@Override
public void decode() throws Exception {
if (!hasDecoded && channel != null && inputStream != null) {
try {
decode(channel, inputStream);
} catch (Throwable e) {
if (log.isWarnEnabled()) {
log.warn("Decode rpc invocation failed: " + e.getMessage(), e);
}
request.setBroken(true);
request.setData(e);
} finally {
hasDecoded = true;
}
}
}
DecodeableRpcInvocation
@Override
public Object decode(Channel channel, InputStream input) throws IOException {
ObjectInput in = CodecSupport.getSerialization(channel.getUrl(), serializationType)
.deserialize(channel.getUrl(), input);
String dubboVersion = in.readUTF();
request.setVersion(dubboVersion);
setAttachment(Constants.DUBBO_VERSION_KEY, dubboVersion);
setAttachment(Constants.PATH_KEY, in.readUTF());
setAttachment(Constants.VERSION_KEY, in.readUTF());
setMethodName(in.readUTF());
try {
Object[] args;
Class<?>[] pts;
String desc = in.readUTF();
if (desc.length() == 0) {
pts = DubboCodec.EMPTY_CLASS_ARRAY;
args = DubboCodec.EMPTY_OBJECT_ARRAY;
} else {
pts = ReflectUtils.desc2classArray(desc);
args = new Object[pts.length];
for (int i = 0; i < args.length; i++) {
try {
args[i] = in.readObject(pts[i]);
} catch (Exception e) {
if (log.isWarnEnabled()) {
log.warn("Decode argument failed: " + e.getMessage(), e);
}
}
}
}
setParameterTypes(pts);
Map<String, String> map = (Map<String, String>) in.readObject(Map.class);
if (map != null && map.size() > 0) {
Map<String, String> attachment = getAttachments();
if (attachment == null) {
attachment = new HashMap<String, String>();
}
attachment.putAll(map);
setAttachments(attachment);
}
//decode argument ,may be callback
for (int i = 0; i < args.length; i++) {
args[i] = decodeInvocationArgument(channel, this, pts, i, args[i]);
}
setArguments(args);
} catch (ClassNotFoundException e) {
throw new IOException(StringUtils.toString("Read invocation data failed.", e));
} finally {
if (in instanceof Cleanable) {
((Cleanable) in).cleanup();
}
}
return this;
}