当网关和服务在实施全链路分布式灰度发布和路由时候，我们需要一款追踪系统来监控网关和服务走的是哪个灰度组，哪个灰度版本，哪个灰度区域，甚至监控从Http Header头部全程传递的灰度规则和路由策略。这个功能意义在于：
笔者尝试调研了一系列分布式追踪系统和中间件，包括Opentracing、Uber Jaeger、Twitter Zipkin、Apache Skywalking、Pinpoint、CAT等，最后决定采用Opentracing + Uber Jaeger方式来实现，重要原因除了易用性和可扩展性外，Opentracing支持WebMvc和WebFlux两种方式，业界的追踪系统能支持WebFlux相对较少
[OpenTracing] OpenTracing已进入CNCF，正在为全球的分布式追踪系统提供统一的概念、规范、架构和数据标准。它通过提供平台无关、厂商无关的API，使得开发人员能够方便的添加（或更换）追踪系统的实现。对于存在多样化的技术栈共存的调用链中，Opentracing适配Java、C、Go和.Net等技术栈，实现全链路分布式追踪功能。迄今为止，Uber Jaeger、Twitter Zipkin和Apache Skywalking已经适配了Opentracing规范
笔者以Nepxion社区的Discovery开源框架（对该开源框架感兴趣的同学，请访问如下链接）为例子展开整合
源码主页，请访问
https://github.com/Nepxion/Discovery
指南主页，请访问
https://github.com/Nepxion/DiscoveryGuide
文档主页，请访问
https://pan.baidu.com/s/1i57rXaNKPuhGRqZ2MONZOA#list/path=%2FNepxion
整合的效果图
灰度调用链主要包括如下11个参数。使用者可以自行定义要传递的调用链参数，例如：traceId, spanId等；也可以自行定义要传递的业务调用链参数，例如：mobile, user等
1. n-d-service-group - 服务所属组或者应用
2. n-d-service-type - 服务类型，分为“网关”和“服务”
3. n-d-service-id - 服务ID
4. n-d-service-address - 服务地址，包括Host和Port
5. n-d-service-version - 服务版本
6. n-d-service-region - 服务所属区域
7. n-d-version - 版本路由值
8. n-d-region - 区域路由值
9. n-d-address - 地址路由值
10. n-d-version-weight - 版本权重路由值
11. n-d-region-weight - 区域权重路由值源码参考
https://github.com/Nepxion/Discovery/tree/master/discovery-plugin-strategy-opentracing
由于OpenTracing扩展需要兼顾到Spring Cloud Gateway、Zuul和服务，它的核心逻辑存在着一定的可封装性，所以笔者抽取出一个公共模块discovery-plugin-strategy-opentracing，包含configuration、operation、context等模块，着重阐述operation模块，其它比较简单，不一一赘述了
在阐述前，笔者需要解释一个配置，该配置将决定核心实现以及终端界面的显示
# 启动和关闭调用链的灰度信息在Opentracing中以独立的Span节点输出，如果关闭，则灰度信息输出到原生的Span节点中。缺失则默认为true
spring.application.strategy.trace.opentracing.separate.span.enabled=trueOpentracing公共操作类 - StrategyOpentracingOperation.java
public class StrategyOpentracingOperation {
private static final Logger LOG = LoggerFactory.getLogger(StrategyOpentracingOperation.class);
@Autowired
protected PluginAdapter pluginAdapter;
@Autowired
protected StrategyContextHolder strategyContextHolder;
@Autowired
private Tracer tracer;
@Value("${" + StrategyOpentracingConstant.SPRING_APPLICATION_STRATEGY_TRACE_OPENTRACING_ENABLED + ":false}")
protected Boolean traceOpentracingEnabled;
@Value("${" + StrategyOpentracingConstant.SPRING_APPLICATION_STRATEGY_TRACE_OPENTRACING_SEPARATE_SPAN_ENABLED + ":true}")
protected Boolean traceOpentracingSeparateSpanEnabled;
public void opentracingInitialize() {
if (!traceOpentracingEnabled) {
return;
}
if (!traceOpentracingSeparateSpanEnabled) {
return;
}
Span span = tracer.buildSpan(DiscoveryConstant.SPAN_VALUE).start();
StrategyOpentracingContext.getCurrentContext().setSpan(span);
LOG.debug("Trace chain for Opentracing initialized...");
}
public void opentracingHeader(Map<String, String> customizationMap) {
if (!traceOpentracingEnabled) {
return;
}
Span span = getCurrentSpan();
if (span == null) {
LOG.error("Span not found in context to opentracing header");
return;
}
if (MapUtils.isNotEmpty(customizationMap)) {
for (Map.Entry<String, String> entry : customizationMap.entrySet()) {
span.setTag(entry.getKey(), entry.getValue());
}
}
if (traceOpentracingSeparateSpanEnabled) {
span.setTag(Tags.COMPONENT.getKey(), DiscoveryConstant.TAG_COMPONENT_VALUE);
}
span.setTag(DiscoveryConstant.PLUGIN, DiscoveryConstant.PLUGIN_VALUE);
span.setTag(DiscoveryConstant.TRACE_ID, span.context().toTraceId());
span.setTag(DiscoveryConstant.SPAN_ID, span.context().toSpanId());
span.setTag(DiscoveryConstant.N_D_SERVICE_GROUP, strategyContextHolder.getHeader(DiscoveryConstant.N_D_SERVICE_GROUP));
...
String routeVersion = strategyContextHolder.getHeader(DiscoveryConstant.N_D_VERSION);
if (StringUtils.isNotEmpty(routeVersion)) {
span.setTag(DiscoveryConstant.N_D_VERSION, routeVersion);
}
...
LOG.debug("Trace chain information outputs to Opentracing...");
}
public void opentracingLocal(String className, String methodName, Map<String, String> customizationMap) {
if (!traceOpentracingEnabled) {
return;
}
Span span = getCurrentSpan();
if (span == null) {
LOG.error("Span not found in context to opentracing local");
return;
}
if (MapUtils.isNotEmpty(customizationMap)) {
for (Map.Entry<String, String> entry : customizationMap.entrySet()) {
span.setTag(entry.getKey(), entry.getValue());
}
}
if (traceOpentracingSeparateSpanEnabled) {
span.setTag(Tags.COMPONENT.getKey(), DiscoveryConstant.TAG_COMPONENT_VALUE);
}
span.setTag(DiscoveryConstant.PLUGIN, DiscoveryConstant.PLUGIN_VALUE);
span.setTag(DiscoveryConstant.CLASS, className);
span.setTag(DiscoveryConstant.METHOD, methodName);
span.setTag(DiscoveryConstant.TRACE_ID, span.context().toTraceId());
span.setTag(DiscoveryConstant.SPAN_ID, span.context().toSpanId());
span.setTag(DiscoveryConstant.N_D_SERVICE_GROUP, pluginAdapter.getGroup());
...
String routeVersion = strategyContextHolder.getHeader(DiscoveryConstant.N_D_VERSION);
if (StringUtils.isNotEmpty(routeVersion)) {
span.setTag(DiscoveryConstant.N_D_VERSION, routeVersion);
}
...
LOG.debug("Trace chain information outputs to Opentracing...");
}
public void opentracingError(String className, String methodName, Throwable e) {
if (!traceOpentracingEnabled) {
return;
}
if (!traceOpentracingSeparateSpanEnabled) {
return;
}
Span span = getCurrentSpan();
if (span == null) {
LOG.error("Span not found in context to opentracing error");
return;
}
span.log(new ImmutableMap.Builder<String, Object>()
.put(DiscoveryConstant.CLASS, className)
.put(DiscoveryConstant.METHOD, methodName)
.put(DiscoveryConstant.EVENT, Tags.ERROR.getKey())
.put(DiscoveryConstant.ERROR_OBJECT, e)
.build());
LOG.debug("Trace chain error outputs to Opentracing...");
}
public void opentracingClear() {
if (!traceOpentracingEnabled) {
return;
}
if (!traceOpentracingSeparateSpanEnabled) {
return;
}
Span span = getCurrentSpan();
if (span != null) {
span.finish();
} else {
LOG.error("Span not found in context to opentracing clear");
}
StrategyOpentracingContext.clearCurrentContext();
LOG.debug("Trace chain context of Opentracing cleared...");
}
public Span getCurrentSpan() {
return traceOpentracingSeparateSpanEnabled ? StrategyOpentracingContext.getCurrentContext().getSpan() : tracer.activeSpan();
}
public String getTraceId() {
if (!traceOpentracingEnabled) {
return null;
}
Span span = getCurrentSpan();
if (span != null) {
return span.context().toTraceId();
}
return null;
}
public String getSpanId() {
if (!traceOpentracingEnabled) {
return null;
}
Span span = getCurrentSpan();
if (span != null) {
return span.context().toSpanId();
}
return null;
}
}实现OpenTracing对服务的扩展，包含configuration、tracer等模块，着重阐述tracer模块，其它比较简单，不一一赘述了
Opentracing的服务追踪类 - DefaultServiceStrategyOpentracingTracer.java
public class DefaultServiceStrategyOpentracingTracer extends DefaultServiceStrategyTracer {
@Autowired
private StrategyOpentracingOperation strategyOpentracingOperation;
@Override
public void trace(ServiceStrategyTracerInterceptor interceptor, MethodInvocation invocation) {
strategyOpentracingOperation.opentracingInitialize();
super.trace(interceptor, invocation);
strategyOpentracingOperation.opentracingLocal(interceptor.getMethod(invocation).getDeclaringClass().getName(), interceptor.getMethodName(invocation), getCustomizationMap());
}
@Override
public void error(ServiceStrategyTracerInterceptor interceptor, MethodInvocation invocation, Throwable e) {
super.error(interceptor, invocation, e);
strategyOpentracingOperation.opentracingError(interceptor.getMethod(invocation).getDeclaringClass().getName(), interceptor.getMethodName(invocation), e);
}
@Override
public void release(ServiceStrategyTracerInterceptor interceptor, MethodInvocation invocation) {
super.release(interceptor, invocation);
strategyOpentracingOperation.opentracingClear();
}
@Override
public String getTraceId() {
return strategyOpentracingOperation.getTraceId();
}
@Override
public String getSpanId() {
return strategyOpentracingOperation.getSpanId();
}
}实现OpenTracing对Spring Cloud Gateway的扩展，跟discovery-plugin-strategy-starter-service-opentracing模块类似，不一一赘述了
源码参考
https://github.com/Nepxion/Discovery/tree/master/discovery-plugin-strategy-starter-zuul-opentracing
实现OpenTracing对Zuul的扩展，跟discovery-plugin-strategy-starter-service-opentracing模块类似，不一一赘述了
示例参考
https://github.com/Nepxion/DiscoveryGuide
Opentracing输出方式以Uber Jaeger为例来说明，步骤非常简单
对于Opentracing调用链功能的开启和关闭，需要通过如下开关做控制：
# 启动和关闭调用链。缺失则默认为false
spring.application.strategy.trace.enabled=true
# 启动和关闭调用链的Opentracing输出，支持F版或更高版本的配置，其它版本不需要该行配置。缺失则默认为false
spring.application.strategy.trace.opentracing.enabled=true
# 启动和关闭调用链的灰度信息在Opentracing中以独立的Span节点输出，如果关闭，则灰度信息输出到原生的Span节点中。缺失则默认为true
spring.application.strategy.trace.opentracing.separate.span.enabled=true自定义调用链上下文参数的创建（该类不是必须的），继承DefaultStrategyTracerAdapter
// 自定义调用链上下文参数的创建
// 对于getTraceId和getSpanId方法，在Opentracing等调用链中间件引入的情况下，由调用链中间件决定，在这里定义不会起作用；在Opentracing等调用链中间件未引入的情况下，在这里定义才有效，下面代码中表示从Http Header中获取，并全链路传递
// 对于getCustomizationMap方法，表示输出到调用链中的定制化业务参数，可以同时输出到日志和Opentracing等调用链中间件，下面代码中表示从Http Header中获取，并全链路传递
public class MyStrategyTracerAdapter extends DefaultStrategyTracerAdapter {
@Override
public String getTraceId() {
return StringUtils.isNotEmpty(strategyContextHolder.getHeader(DiscoveryConstant.TRACE_ID)) ? strategyContextHolder.getHeader(DiscoveryConstant.TRACE_ID) : StringUtils.EMPTY;
}
@Override
public String getSpanId() {
return StringUtils.isNotEmpty(strategyContextHolder.getHeader(DiscoveryConstant.SPAN_ID)) ? strategyContextHolder.getHeader(DiscoveryConstant.SPAN_ID) : StringUtils.EMPTY;
}
@Override
public Map<String, String> getCustomizationMap() {
return new ImmutableMap.Builder<String, String>()
.put("mobile", StringUtils.isNotEmpty(strategyContextHolder.getHeader("mobile")) ? strategyContextHolder.getHeader("mobile") : StringUtils.EMPTY)
.put("user", StringUtils.isNotEmpty(strategyContextHolder.getHeader("user")) ? strategyContextHolder.getHeader("user") : StringUtils.EMPTY)
.build();
}
}
在配置类里@Bean方式进行调用链类创建，覆盖框架内置的调用链类
@Bean
public StrategyTracerAdapter strategyTracerAdapter() {
return new MyStrategyTracerAdapter();
}任浩军， 10 多年开源经历，Github ID：@HaojunRen，Nepxion 开源社区创始人，Nacos Group Member，Spring Cloud Alibaba & Nacos & Sentinel Committer
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转载，请保留原文地址，谢谢 ~
Opentracing + Uber Jaeger 全链路灰度调用链，Nepxion Discovery
原文：https://www.cnblogs.com/Alandre/p/11758210.html