SpringCloud RPC追踪
在滚动自己的RPC工具之前，请检查此处编写的工具和Zipkin的列表。
RPC跟踪通常由拦截器自动完成。它们在幕后添加了与其在RPC操作中的角色相关的标签和事件。
以下示例显示如何添加客户端范围：
@Autowired Tracing tracing; @Autowired Tracer tracer; // before you send a request, add metadata that describes the operation span = tracer.nextSpan().name(service + "/" + method).kind(CLIENT); span.tag("myrpc.version", "1.0.0"); span.remoteServiceName("backend"); span.remoteIpAndPort("172.3.4.1", 8108); // Add the trace context to the request, so it can be propagated in-band tracing.propagation().injector(Request::addHeader) .inject(span.context(), request); // when the request is scheduled, start the span span.start(); // if there is an error, tag the span span.tag("error", error.getCode()); // or if there is an exception span.error(exception); // when the response is complete, finish the span span.finish();
有时，您需要对有请求但无响应的异步操作进行建模。在常规的RPC跟踪中，您使用span.finish()表示已收到响应。在单向跟踪中，由于不希望响应，因此改用span.flush()。
下面的示例显示客户端如何建模单向操作：
@Autowired Tracing tracing; @Autowired Tracer tracer; // start a new span representing a client request oneWaySend = tracer.nextSpan().name(service + "/" + method).kind(CLIENT); // Add the trace context to the request, so it can be propagated in-band tracing.propagation().injector(Request::addHeader) .inject(oneWaySend.context(), request); // fire off the request asynchronously, totally dropping any response request.execute(); // start the client side and flush instead of finish oneWaySend.start().flush();
下面的示例显示服务器如何处理单向操作：
@Autowired Tracing tracing; @Autowired Tracer tracer; // pull the context out of the incoming request extractor = tracing.propagation().extractor(Request::getHeader); // convert that context to a span which you can name and add tags to oneWayReceive = nextSpan(tracer, extractor.extract(request)) .name("process-request") .kind(SERVER) ... add tags etc. // start the server side and flush instead of finish oneWayReceive.start().flush(); // you should not modify this span anymore as it is complete. However, // you can create children to represent follow-up work. next = tracer.newSpan(oneWayReceive.context()).name("step2").start();