咨询关于自定义instrumentation的问题

[callmediaomao]

参考观测云https://docs.guance.com/best-practices/monitoring/ddtrace-instrumentation/#extract 文档进行自定义instrumentation组件。 遇到两个问题想请教下：

1. static/构造器进行transformation.applyadvice无法成功

2. 关于抽象类的埋点我使用了implements Instrumenter.ForTypeHierarchy来，但是无法捕获到，我看到打印了No maven dependency added spring-tx 和 Resolved dependency spring-tx。但是无法进入到对应的增强方法当中。

[lrwh]

问题1：static/构造器进行transformation.applyadvice无法成功

建议输出下日志，用system.out.println();看看是否执行到了这里

如果执行到了，建议开启 debug 模式，可以从debug日志上分析出问题

关于抽象类的埋点我使用了implements Instrumenter.ForTypeHierarchy来，但是无法捕获到，我看到打印了No maven dependency added spring-tx和 Resolved dependency spring-tx。但是无法进入到对应的增强方法当中。

• 检查依赖版本问题，如果没问题，建议贴上build.gradle

• transformation.applyadvice 配置的 advice 有明显错误，应该是packageName+".GetTranscationAdvice"

[callmediaomao]

@lrwh 1. 我打开了debug有出现报错问题，应该是缺少了某一步，但是发现和其他示例没有差别

2. transformation.applyadvice我修改了发现还是不行,并且将ForTypeHierarchy修改为ForSingleType dependencies { compileOnly group: 'org.springframework', name: 'spring-tx', version: '[5.0.4.RELEASE,5.1.10.RELEASE]' } 我采用skywalking的测试用例来测试，里面使用的springboot是5.0.4 其中我在agentbuild.listener打印日志发现 猜测该插件应该没有集成进去。 但是datadog中Dependency的日志让我觉得依赖应该被解析了才对

[lrwh]

@callmediaomao

关于问题一，建议你把 druid 需要做探针的方法贴一下或者druid的源码链接贴一下

关于问题二，建议把 build.gradle全文贴一下，是否生效只需看下面类似的日志

[dd.trace 2023-09-14 15:39:14:441 +0800] [main] DEBUG datadog.trace.agent.tooling.InstrumenterState - Instrumentation applied - instrumentation.names=[java_concurrent,runnable] instrumentation.class=datadog.trace.instrumentation.java.concurrent.RunnableInstrumentation instrumentation.target.classloader=org.springframework.boot.loader.LaunchedURLClassLoader@20e3c449

[callmediaomao]

@lrwh 方便的话可以加微信沟通：17670520466

1. 源码：

   @AutoService(Instrumenter.class)
   public class DruidAddDataSourceInstrumentation extends Instrumenter.Tracing
   implements Instrumenter.ForSingleType {
   
   public DruidAddDataSourceInstrumentation() {
   super("druidDatasource","datasource");
   }
   
   public String instrumentedType() {
   return "com.alibaba.druid.stat.DruidDataSourceStatManager";
   }
   
   public String[] helperClassNames() {
   return new String[]{
       packageName + ".DataSourceDecorator",
   };
   }
   
   public Map<String, String> contextStore() {
   return Collections.singletonMap("java.sql.Connection", DBInfo.class.getName());
   }
   
   public void adviceTransformations(AdviceTransformation transformation) {
   transformation.applyAdvice(
       isMethod()
           .and(isStatic())
           .and(named("addDataSource"))
           .and(takesArguments(2).and(takesArgument(0, Object.class)))
           .and(returns(named("javax.management.ObjectName"))),
   
       DruidAddDataSourceInstrumentation.class.getName() + "$DataSourceAdvice"
   );
   }
   
   public static class DataSourceAdvice {
   
   @Advice.OnMethodEnter(suppress = Throwable.class)
   public static AgentScope onEnter(
       @Advice.This final DruidDataSourceStatManager ds,
       @Advice.Argument(0) final Object druidDataSource
   ) {
     try {
       AgentSpan span = startSpan("datasource", "datasource.addDataSource");
       DataSourceDecorator.DECORATE.afterStart(span);
       Connection connection = ((DruidDataSource)druidDataSource).getConnection();
       DataSourceDecorator.DECORATE.onConnection(span,connection, InstrumentationContext.get(Connection.class, DBInfo.class));
       AgentScope agentScope = activateSpan(span);
       connection.close();
       return agentScope;
     } catch (SQLException e) {
       return null;
     }
   }
   
   @Advice.OnMethodExit(onThrowable = Throwable.class, suppress = Throwable.class)
   public static void stopSpan(
       @Advice.Enter final AgentScope scope,
       @Advice.Thrown final Throwable throwable) {
     if (scope == null) {
       return;
     }
     DataSourceDecorator.DECORATE.onError(scope, throwable);
     DataSourceDecorator.DECORATE.beforeFinish(scope);
     scope.close();
     scope.span().finish();
   }
   }
   }

2. Gradle全文，打印未发现对应的日志

   
   apply from: "$rootDir/gradle/java.gradle"
   apply plugin: 'call-site-instrumentation'

dependencies { compileOnly group: 'org.springframework', name: 'spring-tx', version: '[5.0.4.RELEASE,5.1.10.RELEASE]' }

[callmediaomao]

@lrwh 第一个问题我发现我写了@Advice.This是导致报错的原因，我修改了，然后出现了类加载器阻塞😫 [dd.trace 2023-09-14 18:54:26:429 +0800] [main] DEBUG datadog.trace.agent.tooling.InstrumenterState - Instrumentation blocked - instrumentation.names=[druidDatasource,datasource] instrumentation.class=datadog.trace.instrumentation.datasource.DruidAddDataSourceInstrumentation instrumentation.target.classloader=sun.misc.Launcher$AppClassLoader@18b4aac2

[lrwh]

@callmediaomao 问题1： 建议调整下DruidAddDataSourceInstrumentation，看看是否有日志输出

 public void adviceTransformations(AdviceTransformation transformation) {
    transformation.applyAdvice(
        isMethod()
            .and(isStatic())
            .and(named("addDataSource"))),

        DruidAddDataSourceInstrumentation.class.getName() + "$DataSourceAdvice"
    );
  }

  public static class DataSourceAdvice {

    @Advice.OnMethodEnter(suppress = Throwable.class)
    public static AgentScope onEnter( ) {
       System.out.println("do DataSourceAdvice")
     return null;
    }

  }

问题2： gradle 文件缺少了 muzzle部分，所以不会生效，可参考文档 ddtrace 系列篇之实战：自定义 Apache-Dubbo Instrumentation.

[callmediaomao]

@lrwh 问题2的build.gradle我添加了还是不生效

muzzle {
  pass {
    group = 'org.springframework'
    module = 'spring-tx'
    versions = "5.0.4.RELEASE"
    // assertInverse = true
  }
}

[lrwh]

@callmediaomao

试试以下配置

muzzle {
  pass {
    group = 'org.springframework'
    module = 'spring-tx'
    versions = "[5.0.0,]"
    // assertInverse = true
  }
}

[callmediaomao]

@lrwh 也不行，我怀疑是没有依赖注入进去。进入了 listener onignore方法当中