We first look at the diagram BoltClientProxyInvoker
So when we actually BoltClientProxyInvoker # invoke method calls invoke the parent class
ClientProxyInvoker # invoke
@Override
public SofaResponse invoke(SofaRequest request) throws SofaRpcException {
SofaResponse response = null;
Throwable throwable = null;
try {
RpcInternalContext.pushContext();
RpcInternalContext context = RpcInternalContext.getContext();
context.setProviderSide(false);
// 包装request请求
decorateRequest(request);
try {
// 产生开始调用事件
if (EventBus.isEnable(ClientStartInvokeEvent.class)) {
EventBus.post(new ClientStartInvokeEvent(request));
}
// 得到结果
response = cluster.invoke(request);
} catch (SofaRpcException e) {
throwable = e;
throw e;
} finally {
// 产生调用结束事件
if (!request.isAsync()) {
if (EventBus.isEnable(ClientEndInvokeEvent.class)) {
EventBus.post(new ClientEndInvokeEvent(request, response, throwable));
}
}
}
// 包装响应
decorateResponse(response);
return response;
} finally {
RpcInternalContext.removeContext();
RpcInternalContext.popContext();
}
}This method is mainly to do a few things:
- Packaging REQUEST request, setting the necessary parameters
- FailOverCluster invoke method call, a request is sent to reques, and to give a corresponding response
- Packaging response response
invoker of the parent class AbstractCluster when we call FailOverCluster is actually called, FailOverCluster diagram as follows:
So we enter into the invoker of the method AbstractCluster:
@Override
public SofaResponse invoke(SofaRequest request) throws SofaRpcException {
SofaResponse response = null;
try {
// 做一些初始化检查，例如未连接可以连接
checkClusterState();
// 开始调用
countOfInvoke.incrementAndGet(); // 计数+1
response = doInvoke(request);
return response;
} catch (SofaRpcException e) {
// 客户端收到异常（客户端自己的异常）
throw e;
} finally {
countOfInvoke.decrementAndGet(); // 计数-1
}
}checkClusterState method is mainly used to check whether already destroyed, or call the init method.
Then you will remember what number before calling.
Then we enter into doInvoke method:
public SofaResponse doInvoke(SofaRequest request) throws SofaRpcException {
String methodName = request.getMethodName();
int retries = consumerConfig.getMethodRetries(methodName);
int time = 0;
SofaRpcException throwable = null;// 异常日志
List<ProviderInfo> invokedProviderInfos = new ArrayList<ProviderInfo>(retries + 1);
do {
//负载均衡
ProviderInfo providerInfo = select(request, invokedProviderInfos);
try {
//调用过滤器链
SofaResponse response = filterChain(providerInfo, request);
if (response != null) {
if (throwable != null) {
if (LOGGER.isWarnEnabled(consumerConfig.getAppName())) {
LOGGER.warnWithApp(consumerConfig.getAppName(),
LogCodes.getLog(LogCodes.WARN_SUCCESS_BY_RETRY,
throwable.getClass() + ":" + throwable.getMessage(),
invokedProviderInfos));
}
}
return response;
} else {
throwable = new SofaRpcException(RpcErrorType.CLIENT_UNDECLARED_ERROR,
"Failed to call " + request.getInterfaceName() + "." + methodName
+ " on remote server " + providerInfo + ", return null");
time++;
}
} catch (SofaRpcException e) { // 服务端异常+ 超时异常 才发起rpc异常重试
if (e.getErrorType() == RpcErrorType.SERVER_BUSY
|| e.getErrorType() == RpcErrorType.CLIENT_TIMEOUT) {
throwable = e;
time++;
} else {
throw e;
}
} catch (Exception e) { // 其它异常不重试
throw new SofaRpcException(RpcErrorType.CLIENT_UNDECLARED_ERROR,
"Failed to call " + request.getInterfaceName() + "." + request.getMethodName()
+ " on remote server: " + providerInfo + ", cause by unknown exception: "
+ e.getClass().getName() + ", message is: " + e.getMessage(), e);
} finally {
if (RpcInternalContext.isAttachmentEnable()) {
RpcInternalContext.getContext().setAttachment(RpcConstants.INTERNAL_KEY_INVOKE_TIMES,
time + 1); // 重试次数
}
}
invokedProviderInfos.add(providerInfo);
} while (time <= retries);
throw throwable;
}This method is mainly done inside this matter:
- If it fails to cycle call
- Load balancing, select the provider
- Calling the server through the filter chain, and returns the result
- Exception Handling
Then we enter into filterChain method according to the filter chain will skip to the last of the invoke method ConsumerInvoker
@Override
public SofaResponse invoke(SofaRequest sofaRequest) throws SofaRpcException {
// 设置下服务器应用
ProviderInfo providerInfo = RpcInternalContext.getContext().getProviderInfo();
String appName = providerInfo.getStaticAttr(ProviderInfoAttrs.ATTR_APP_NAME);
if (StringUtils.isNotEmpty(appName)) {
sofaRequest.setTargetAppName(appName);
}
// 目前只是通过client发送给服务端
return consumerBootstrap.getCluster().sendMsg(providerInfo, sofaRequest);
}consumerBootstrap.getCluster () returns FailOverCluster instance, and then call the parent class AbstractCluster of sendMsg
public SofaResponse sendMsg(ProviderInfo providerInfo, SofaRequest request) throws SofaRpcException {
ClientTransport clientTransport = connectionHolder.getAvailableClientTransport(providerInfo);
if (clientTransport != null && clientTransport.isAvailable()) {
return doSendMsg(providerInfo, clientTransport, request);
} else {
throw unavailableProviderException(request.getTargetServiceUniqueName(), providerInfo.getOriginUrl());
}
}
protected SofaResponse doSendMsg(ProviderInfo providerInfo, ClientTransport transport,
SofaRequest request) throws SofaRpcException {
RpcInternalContext context = RpcInternalContext.getContext();
// 添加调用的服务端远程地址
RpcInternalContext.getContext().setRemoteAddress(providerInfo.getHost(), providerInfo.getPort());
try {
checkProviderVersion(providerInfo, request); // 根据服务端版本特殊处理
String invokeType = request.getInvokeType();
int timeout = resolveTimeout(request, consumerConfig, providerInfo);
SofaResponse response = null;
// 同步调用
if (RpcConstants.INVOKER_TYPE_SYNC.equals(invokeType)) {
long start = RpcRuntimeContext.now();
try {
response = transport.syncSend(request, timeout);
} finally {
if (RpcInternalContext.isAttachmentEnable()) {
long elapsed = RpcRuntimeContext.now() - start;
context.setAttachment(RpcConstants.INTERNAL_KEY_CLIENT_ELAPSE, elapsed);
}
}
}
// 单向调用
else if (RpcConstants.INVOKER_TYPE_ONEWAY.equals(invokeType)) {
long start = RpcRuntimeContext.now();
try {
transport.oneWaySend(request, timeout);
response = buildEmptyResponse(request);
} finally {
if (RpcInternalContext.isAttachmentEnable()) {
long elapsed = RpcRuntimeContext.now() - start;
context.setAttachment(RpcConstants.INTERNAL_KEY_CLIENT_ELAPSE, elapsed);
}
}
}
// Callback调用
else if (RpcConstants.INVOKER_TYPE_CALLBACK.equals(invokeType)) {
// 调用级别回调监听器
SofaResponseCallback sofaResponseCallback = request.getSofaResponseCallback();
if (sofaResponseCallback == null) {
SofaResponseCallback methodResponseCallback = consumerConfig
.getMethodOnreturn(request.getMethodName());
if (methodResponseCallback != null) { // 方法的Callback
request.setSofaResponseCallback(methodResponseCallback);
}
}
// 记录发送开始时间
context.setAttachment(RpcConstants.INTERNAL_KEY_CLIENT_SEND_TIME, RpcRuntimeContext.now());
// 开始调用
transport.asyncSend(request, timeout);
response = buildEmptyResponse(request);
}
// Future调用
else if (RpcConstants.INVOKER_TYPE_FUTURE.equals(invokeType)) {
// 记录发送开始时间
context.setAttachment(RpcConstants.INTERNAL_KEY_CLIENT_SEND_TIME, RpcRuntimeContext.now());
// 开始调用
ResponseFuture future = transport.asyncSend(request, timeout);
// 放入线程上下文
RpcInternalContext.getContext().setFuture(future);
response = buildEmptyResponse(request);
} else {
throw new SofaRpcException(RpcErrorType.CLIENT_UNDECLARED_ERROR, "Unknown invoke type:" + invokeType);
}
return response;
} catch (SofaRpcException e) {
throw e;
} catch (Throwable e) { // 客户端其它异常
throw new SofaRpcException(RpcErrorType.CLIENT_UNDECLARED_ERROR, e);
}
}sendMsg last method calls to doSendMsg.
soSendMsg which mainly do the following things:
- If a synchronous call returns directly encapsulated parameter
- If it is a one-way call, the call buildEmptyResponse method returns an empty response
- 如果是callback调用asyncSend，RPC在获取到服务端的结果后会自动执行该回调实现。
- 服务端返回响应结果被 RPC 缓存，当客户端需要响应结果的时候需要主动获取结果，获取结果的过程阻塞线程。