说在前面
接上次
源码解析
进入这个方法org.apache.rocketmq.remoting.netty.NettyRemotingClient#invokeOneway发送单途请求
@Override
public void invokeOneway(String addr, RemotingCommand request, long timeoutMillis) throws InterruptedException,
RemotingConnectException, RemotingTooMuchRequestException, RemotingTimeoutException, RemotingSendRequestException {
// 获取channel=》
final Channel channel = this.getAndCreateChannel(addr);
if (channel != null && channel.isActive()) {
try {
if (this.rpcHook != null) {
// 执行请求执行前的钩子方法
this.rpcHook.doBeforeRequest(addr, request);
}
// 执行单线请求 =》
this.invokeOnewayImpl(channel, request, timeoutMillis);
} catch (RemotingSendRequestException e) {
log.warn("invokeOneway: send request exception, so close the channel[{}]", addr);
// 异常关闭channel=》
this.closeChannel(addr, channel);
throw e;
}
} else {
this.closeChannel(addr, channel);
throw new RemotingConnectException(addr);
}
}
进入这个方法org.apache.rocketmq.remoting.netty.NettyRemotingClient#getAndCreateChannel获取channel
private Channel getAndCreateChannel(final String addr) throws InterruptedException {
if (null == addr) {
// =》
return getAndCreateNameserverChannel();
}
ChannelWrapper cw = this.channelTables.get(addr);
if (cw != null && cw.isOK()) {
return cw.getChannel();
}
// =》
return this.createChannel(addr);
}
进入这个方法org.apache.rocketmq.remoting.netty.NettyRemotingClient#getAndCreateNameserverChannel获取namrsrv通信的channel
private Channel getAndCreateNameserverChannel() throws InterruptedException {
String addr = this.namesrvAddrChoosed.get();
if (addr != null) {
ChannelWrapper cw = this.channelTables.get(addr);
if (cw != null && cw.isOK()) {
return cw.getChannel();
}
}
// 从namesrvAddrChoosed中查找namesrv，如果不存在同步轮询的方式从namesrvAddrList中取
final List addrList = this.namesrvAddrList.get();
if (this.lockNamesrvChannel.tryLock(LOCK_TIMEOUT_MILLIS, TimeUnit.MILLISECONDS)) {
try {
addr = this.namesrvAddrChoosed.get();
if (addr != null) {
ChannelWrapper cw = this.channelTables.get(addr);
if (cw != null && cw.isOK()) {
return cw.getChannel();
}
}
if (addrList != null && !addrList.isEmpty()) {
for (int i = 0; i < addrList.size(); i++) {
int index = this.namesrvIndex.incrementAndGet();
index = Math.abs(index);
index = index % addrList.size();
String newAddr = addrList.get(index);
this.namesrvAddrChoosed.set(newAddr);
log.info("new name server is chosen. OLD: {} , NEW: {}. namesrvIndex = {}", addr, newAddr, namesrvIndex);
// 同步创建渠道
Channel channelNew = this.createChannel(newAddr);
if (channelNew != null) {
return channelNew;
}
}
}
} catch (Exception e) {
log.error("getAndCreateNameserverChannel: create name server channel exception", e);
} finally {
this.lockNamesrvChannel.unlock();
}
} else {
log.warn("getAndCreateNameserverChannel: try to lock name server, but timeout, {}ms", LOCK_TIMEOUT_MILLIS);
}
return null;
}
进入到这个方法org.apache.rocketmq.remoting.netty.NettyRemotingClient#createChannel同步创建channel
private Channel createChannel(final String addr) throws InterruptedException {
ChannelWrapper cw = this.channelTables.get(addr);
// 代码走到这里，这里的逻辑正常情况下是走不到的，为了代码严谨性
if (cw != null && cw.isOK()) {
cw.getChannel().close();
channelTables.remove(addr);
}
if (this.lockChannelTables.tryLock(LOCK_TIMEOUT_MILLIS, TimeUnit.MILLISECONDS)) {
try {
boolean createNewConnection;
// 为了代码严谨性，这里又做了一次判断
cw = this.channelTables.get(addr);
if (cw != null) {
if (cw.isOK()) {
cw.getChannel().close();
this.channelTables.remove(addr);
createNewConnection = true;
// 如果channel还在用，不让创建
} else if (!cw.getChannelFuture().isDone()) {
createNewConnection = false;
} else {
this.channelTables.remove(addr);
createNewConnection = true;
}
} else {
createNewConnection = true;
}
if (createNewConnection) {
// 重新建立连接
ChannelFuture channelFuture = this.bootstrap.connect(RemotingHelper.string2SocketAddress(addr));
log.info("createChannel: begin to connect remote host[{}] asynchronously", addr);
cw = new ChannelWrapper(channelFuture);
// 建立的channel也放到本次缓存中
this.channelTables.put(addr, cw);
}
} catch (Exception e) {
log.error("createChannel: create channel exception", e);
} finally {
this.lockChannelTables.unlock();
}
} else {
log.warn("createChannel: try to lock channel table, but timeout, {}ms", LOCK_TIMEOUT_MILLIS);
}
if (cw != null) {
ChannelFuture channelFuture = cw.getChannelFuture();
if (channelFuture.awaitUninterruptibly(this.nettyClientConfig.getConnectTimeoutMillis())) {
// 对channel再次判断
if (cw.isOK()) {
log.info("createChannel: connect remote host[{}] success, {}", addr, channelFuture.toString());
return cw.getChannel();
} else {
log.warn("createChannel: connect remote host[" + addr + "] failed, " + channelFuture.toString(), channelFuture.cause());
}
} else {
log.warn("createChannel: connect remote host[{}] timeout {}ms, {}", addr, this.nettyClientConfig.getConnectTimeoutMillis(),
channelFuture.toString());
}
}
return null;
}
往上返回到这个方法org.apache.rocketmq.remoting.netty.NettyRemotingAbstract#invokeOnewayImpl执行单途实现
public void invokeOnewayImpl(final Channel channel, final RemotingCommand request, final long timeoutMillis)
throws InterruptedException, RemotingTooMuchRequestException, RemotingTimeoutException, RemotingSendRequestException {
request.markOnewayRPC();
// 获取信号量的信号
boolean acquired = this.semaphoreOneway.tryAcquire(timeoutMillis, TimeUnit.MILLISECONDS);
if (acquired) {
final SemaphoreReleaseOnlyOnce once = new SemaphoreReleaseOnlyOnce(this.semaphoreOneway);
try {
channel.writeAndFlush(request).addListener(new ChannelFutureListener() {
@Override
public void operationComplete(ChannelFuture f) throws Exception {
once.release();
if (!f.isSuccess()) {
log.warn("send a request command to channel <" + channel.remoteAddress() + "> failed.");
}
}
});
} catch (Exception e) {
once.release();
log.warn("write send a request command to channel <" + channel.remoteAddress() + "> failed.");
throw new RemotingSendRequestException(RemotingHelper.parseChannelRemoteAddr(channel), e);
}
} else {
if (timeoutMillis <= 0) {
throw new RemotingTooMuchRequestException("invokeOnewayImpl invoke too fast");
} else {
String info = String.format(
"invokeOnewayImpl tryAcquire semaphore timeout, %dms, waiting thread nums: %d semaphoreAsyncValue: %d",
timeoutMillis,
this.semaphoreOneway.getQueueLength(),
this.semaphoreOneway.availablePermits()
);
log.warn(info);
throw new RemotingTimeoutException(info);
}
}
}
往上返回到这个方法org.apache.rocketmq.remoting.netty.NettyRemotingClient#closeChannel(java.lang.String, io.netty.channel.Channel)异常同步关闭channel
public void closeChannel(final String addr, final Channel channel) {
if (null == channel)
return;
final String addrRemote = null == addr ? RemotingHelper.parseChannelRemoteAddr(channel) : addr;
try {
if (this.lockChannelTables.tryLock(LOCK_TIMEOUT_MILLIS, TimeUnit.MILLISECONDS)) {
try {
boolean removeItemFromTable = true;
final ChannelWrapper prevCW = this.channelTables.get(addrRemote);
log.info("closeChannel: begin close the channel[{}] Found: {}", addrRemote, prevCW != null);
if (null == prevCW) {
log.info("closeChannel: the channel[{}] has been removed from the channel table before", addrRemote);
removeItemFromTable = false;
} else if (prevCW.getChannel() != channel) {
log.info("closeChannel: the channel[{}] has been closed before, and has been created again, nothing to do.",
addrRemote);
removeItemFromTable = false;
}
if (removeItemFromTable) {
// 删除缓存中的channel
this.channelTables.remove(addrRemote);
log.info("closeChannel: the channel[{}] was removed from channel table", addrRemote);
}
// 关闭channel
RemotingUtil.closeChannel(channel);
} catch (Exception e) {
log.error("closeChannel: close the channel exception", e);
} finally {
this.lockChannelTables.unlock();
}
} else {
log.warn("closeChannel: try to lock channel table, but timeout, {}ms", LOCK_TIMEOUT_MILLIS);
}
} catch (InterruptedException e) {
log.error("closeChannel exception", e);
}
}
往上返回到这个方法org.apache.rocketmq.remoting.netty.NettyRemotingClient#invokeSync broker同步向namesrv注册
@Override
public RemotingCommand invokeSync(String addr, final RemotingCommand request, long timeoutMillis)
throws InterruptedException, RemotingConnectException, RemotingSendRequestException, RemotingTimeoutException {
long beginStartTime = System.currentTimeMillis();
// 获取并创建channel =》
final Channel channel = this.getAndCreateChannel(addr);
if (channel != null && channel.isActive()) {
try {
if (this.rpcHook != null) {
// 执行请求前钩子方法
this.rpcHook.doBeforeRequest(addr, request);
}
long costTime = System.currentTimeMillis() - beginStartTime;
if (timeoutMillis < costTime) {
throw new RemotingTimeoutException("invokeSync call timeout");
}
// 执行同步请求 =》
RemotingCommand response = this.invokeSyncImpl(channel, request, timeoutMillis - costTime);
if (this.rpcHook != null) {
// 执行响应后钩子方法 =》
this.rpcHook.doAfterResponse(RemotingHelper.parseChannelRemoteAddr(channel), request, response);
}
return response;
} catch (RemotingSendRequestException e) {
log.warn("invokeSync: send request exception, so close the channel[{}]", addr);
// 出现异常，channel关闭 =》
this.closeChannel(addr, channel);
throw e;
} catch (RemotingTimeoutException e) {
if (nettyClientConfig.isClientCloseSocketIfTimeout()) {
this.closeChannel(addr, channel);
log.warn("invokeSync: close socket because of timeout, {}ms, {}", timeoutMillis, addr);
}
log.warn("invokeSync: wait response timeout exception, the channel[{}]", addr);
throw e;
}
} else {
this.closeChannel(addr, channel);
throw new RemotingConnectException(addr);
}
}
进入这个方法org.apache.rocketmq.remoting.netty.NettyRemotingClient#getAndCreateChannel创建channel，前面介绍过了。
进入这个方法org.apache.rocketmq.remoting.netty.NettyRemotingAbstract#invokeSyncImpl同步处理实现
public RemotingCommand invokeSyncImpl(final Channel channel, final RemotingCommand request,
final long timeoutMillis)
throws InterruptedException, RemotingSendRequestException, RemotingTimeoutException {
final int opaque = request.getOpaque();
try {
final ResponseFuture responseFuture = new ResponseFuture(channel, opaque, timeoutMillis, null, null);
// 缓存正在进行的请求
this.responseTable.put(opaque, responseFuture);
final SocketAddress addr = channel.remoteAddress();
channel.writeAndFlush(request).addListener(new ChannelFutureListener() {
@Override
public void operationComplete(ChannelFuture f) throws Exception {
if (f.isSuccess()) {
responseFuture.setSendRequestOK(true);
return;
} else {
responseFuture.setSendRequestOK(false);
}
responseTable.remove(opaque);
responseFuture.setCause(f.cause());
// 响应解析完毕会解除countDownLatch的阻塞 =》
responseFuture.putResponse(null);
log.warn("send a request command to channel <" + addr + "> failed.");
}
});
// 这里用countDownLatch实现的阻塞 =》
RemotingCommand responseCommand = responseFuture.waitResponse(timeoutMillis);
if (null == responseCommand) {
if (responseFuture.isSendRequestOK()) {
throw new RemotingTimeoutException(RemotingHelper.parseSocketAddressAddr(addr), timeoutMillis,
responseFuture.getCause());
} else {
throw new RemotingSendRequestException(RemotingHelper.parseSocketAddressAddr(addr), responseFuture.getCause());
}
}
return responseCommand;
} finally {
this.responseTable.remove(opaque);
}
}
进入这个方法org.apache.rocketmq.remoting.netty.NettyRemotingClient#closeChannel(java.lang.String, io.netty.channel.Channel)异常关闭channel，前面介绍过了。
往上返回到这个方法org.apache.rocketmq.broker.topic.TopicConfigManager#updateOrderTopicConfig更新topic配置
public void updateOrderTopicConfig(final KVTable orderKVTableFromNs) {
if (orderKVTableFromNs != null && orderKVTableFromNs.getTable() != null) {
boolean isChange = false;
Set orderTopics = orderKVTableFromNs.getTable().keySet();
for (String topic : orderTopics) {
TopicConfig topicConfig = this.topicConfigTable.get(topic);
if (topicConfig != null && !topicConfig.isOrder()) {
topicConfig.setOrder(true);
isChange = true;
log.info("update order topic config, topic={}, order={}", topic, true);
}
}
for (Map.Entry entry : this.topicConfigTable.entrySet()) {
String topic = entry.getKey();
if (!orderTopics.contains(topic)) {
TopicConfig topicConfig = entry.getValue();
if (topicConfig.isOrder()) {
topicConfig.setOrder(false);
isChange = true;
log.info("update order topic config, topic={}, order={}", topic, false);
}
}
}
if (isChange) {
// 更新数据版本号
this.dataVersion.nextVersion();
// 持久化=》
this.persist();
}
}
}
往上返回到这个方法org.apache.rocketmq.broker.processor.AdminBrokerProcessor#updateAndCreateTopic 创建或更新topic解析完毕。
说在最后
本次解析仅代表个人观点，仅供参考。
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