sleuth和zipkin调试流程图（手工创建span上报）

Y

跟踪进去

N

关闭方法里执行后续所有的逻辑

throw new IllegalStateException(\t\t\t\t\t\t\"Span for \" + this.name + \" has not been started\");

手工创建span上报流程图

循环加入父span到span上下文，此处只有一个父span，所以while只执行一次

SpanContext current = CURRENT_SPAN.get();

org.springframework.cloud.sleuth.instrument.web.client.TraceHttpResponse#close

span != null && parent != null

span.isExportable()根据配置判断是否需要上报

org.springframework.cloud.sleuth.instrument.web.client.AbstractTraceHttpRequestInterceptor#finish

执行关闭response和关闭span

添加第三个span的cs事件并关闭且上报

org.springframework.cloud.sleuth.trace.DefaultTracer#close

判断span的标签是否含有LC，此时是刚手工创建的span，所有不包含，继续往下执行此时的processid为unknown的字节码，创建lc的BinaryAnnotation组件，并加入span的set集合中

org.springframework.cloud.sleuth.trace.SpanContextHolder#close(org.springframework.cloud.sleuth.trace.SpanContextHolder.SpanFunction)

org.springframework.cloud.sleuth.zipkin.ZipkinSpanListener#convert

this.tracer.close(this.currentSpan());

结束：return null

关闭第三个span

!this.pending.offer(span)

org.springframework.web.client.RestTemplate#doExecute

创建第二个新span

this.spanMetricReporter.incrementAcceptedSpans(1);

log(\"With parent: {}\

org.springframework.cloud.sleuth.zipkin.ZipkinSpanListener#report

span.stop();

执行上报所有逻辑

span.equals(cur)

if (span.tags().containsKey(Constants.LOCAL_COMPONENT)) {   return;  }  byte[] processId = span.getProcessId() != null    ? span.getProcessId().toLowerCase().getBytes(UTF_8)    : UNKNOWN_BYTES;  BinaryAnnotation component = BinaryAnnotation.builder()    .type(BinaryAnnotation.Type.STRING)    .key(\"lc\") // LOCAL_COMPONENT    .value(processId)    .endpoint(this.endpointLocator.local()).build();  zipkinSpan.addBinaryAnnotation(component);

org.springframework.cloud.sleuth.metric.CounterServiceBasedSpanMetricReporter#incrementAcceptedSpans@Override public void incrementAcceptedSpans(long quantity) {  for (int i = 0; i < quantity; i++) {   this.counterService.increment(this.acceptedSpansMetricName);  } }

抛异常：\"Tried to close span but \" + \"it is not the current span: \" + span\t\t\t\t\t\t\t+ \". You may have forgotten to close or detach \" + cur

不做任何操作

log.error(\"Zipkin doesn't support spans with multiple parents. Omitting \"      + \"other parents for \" + span);

CURRENT_SPAN.remove();

创建span对象

跟踪进去：加时间日志和关闭当前手动创建的span

手工创建span上报后，通过拦截器关闭并上报第三个span--->后台接口返回时上报

final Span savedSpan = span.getSavedSpan();

!isTracing()

org.springframework.cloud.sleuth.zipkin.ZipkinSpanListener#ensureServerAddr

跟踪进去convert方法

关闭当前span以及其所有父span

N：继续给span赋值属性

this.interceptor.finish();

org.springframework.cloud.sleuth.trace.SpanContextHolder#CURRENT_SPAN---------------------------------private static final ThreadLocal<SpanContext> CURRENT_SPAN = new NamedThreadLocal<>(   \"Trace Context\");

org.springframework.cloud.sleuth.trace.DefaultTracer#createSpan(java.lang.String)

this.spanReporter.report(span);

org.springframework.cloud.sleuth.zipkin.ZipkinSpanListener#notClientOrServer

this.reporter.report(convert(span));

Add annotations from the sleuth Span.

结束： return savedSpan;

while (current != null) {   current = current.parent;   spanFunction.apply(current != null ? current.span : null);   if (current != null) {    if (!current.autoClose) {     CURRENT_SPAN.set(current);     current = null;    }   }  }

org.springframework.cloud.sleuth.zipkin.ZipkinSpanListener#addZipkinAnnotations

判断span中logs的size是否为0，第一个span肯定为0，如果不为0，则判断log中是否有cr或者sr事件，如果有则返回false

savedSpan != null && span.getParents().contains(savedSpan.getSpanId())

通过close方法中传入的span获取需要保存的span

MDC.remove(Span.SPAN_ID_NAME);\t\t\tMDC.remove(Span.SPAN_EXPORT_NAME);\t\t\tMDC.remove(Span.TRACE_ID_NAME);

跟踪进去report方法

zipkinSpan.timestamp(span.getBegin() * 1000L);  zipkinSpan.duration(span.getAccumulatedMillis() * 1000L);  zipkinSpan.traceId(span.getTraceId());

for (Log log : span.logs()) {   if (ZIPKIN_START_EVENTS.contains(log.getEvent())) {    return false;   }  }  return true;

ResponseEntity<String> forEntity = restTemplate.getForEntity(new URI(\"http://localhost:\"+otherappPort+\"/getTime\

拦截器TraceRestTemplateInteceptor------------------------* Interceptor that verifies whether the trance and span id has been set on the request * and sets them if one or both of them are missing.

（close方法唯一的入参span）span == null

调用成员变量spanReporter的report方法

此拦截器为TraceHttpResponse的成员变量

判断是否是起始span判断是否有父span

什么都不做

org.slf4j.MDC#remove日志删除

org.springframework.cloud.sleuth.zipkin.ZipkinSpanListener#hasClientSend

跟踪进去：循环对父span调用logStoppedSpan

span.getParents().size() > 0

hasClientSend(span)

close方法唯一的入参和当前span上下文中的span是否相等

Y：错误提示只能有一个父span

this.end = System.currentTimeMillis();

org.springframework.cloud.sleuth.Span#stop

zipkinSpan.parentId(span.getParents().get(0));

不做任何操作即计数器不减1

currentSpan().logEvent(Span.CLIENT_RECV);

this.begin == 0

span.getParents().size() > 1

/**\t * Close the current span and all parents that can be auto closed.\t * On every iteration a function will be applied on the closed Span.\t */

zipkinSpan.id(span.getSpanId());  if (StringUtils.hasText(span.getName())) {   zipkinSpan.name(span.getName());  }  return zipkinSpan.build();

notClientOrServer(span)

减去1this.spanMetricReporter.incrementDroppedSpans(1)

finally（关闭此新建的span）

private boolean hasClientSend(Span span) {\t\tfor (org.springframework.cloud.sleuth.Log log : span.logs()) {\t\t\tif (Constants.CLIENT_SEND.equals(log.getEvent())) {\t\t\t\treturn !span.tags().containsKey(Constants.SERVER_ADDR);\t\t\t}\t\t}\t\treturn false;\t}

关闭第二个span

this.end == 0

this.delegate.close();

org.springframework.cloud.sleuth.zipkin.HttpZipkinSpanReporter#report

Span cur = SpanContextHolder.getCurrentSpan();

跟踪进去实际上就是给此span的结束时间赋值

取第一个父spanID

zipkin.Span.Builder zipkinSpan = zipkin.Span.builder();