SpringBoot 2.x升级至3.3.3：指标模块兼容性问题咨询

核心思路 #

SpringBoot 3.x采用Micrometer Observation框架替代了旧的Metrics模型，http.server.requests的标签由ServerRequestObservationConvention组件控制。要恢复2.x版本包含error、exception标签的样式，只需自定义该Convention并注册为Spring Bean，复用默认逻辑的同时补充所需标签即可。

实现步骤 #

1. 自定义Observation Convention #

创建类实现ServerRequestObservationConvention，在复用默认标签逻辑的基础上，添加error和exception标签的生成逻辑，覆盖所有异常场景（包括Controller抛出的业务异常、Spring Security拦截的401/403异常）：

import io.micrometer.common.KeyValue;
import io.micrometer.common.KeyValues;
import org.springframework.http.server.observation.DefaultServerRequestObservationConvention;
import org.springframework.http.server.observation.ServerRequestObservationContext;
import org.springframework.http.server.observation.ServerRequestObservationConvention;
import org.springframework.web.context.request.RequestAttributes;
import org.springframework.web.context.request.RequestContextHolder;

import javax.servlet.http.HttpServletRequest;
import java.util.Optional;

public class LegacyServerRequestObservationConvention implements ServerRequestObservationConvention {

    // 复用默认实现，避免重复编写基础标签逻辑
    private final ServerRequestObservationConvention delegate = new DefaultServerRequestObservationConvention();

    @Override
    public KeyValues getLowCardinalityKeyValues(ServerRequestObservationContext context) {
        // 在默认标签集合中追加error和exception标签
        return delegate.getLowCardinalityKeyValues(context)
                .and(getErrorKeyValue(context))
                .and(getExceptionKeyValue(context));
    }

    @Override
    public KeyValues getHighCardinalityKeyValues(ServerRequestObservationContext context) {
        return delegate.getHighCardinalityKeyValues(context);
    }

    @Override
    public String getName() {
        return delegate.getName();
    }

    @Override
    public String getContextualName(ServerRequestObservationContext context) {
        return delegate.getContextualName(context);
    }

    // 生成error标签：取异常类名，无异常则为"none"
    private KeyValue getErrorKeyValue(ServerRequestObservationContext context) {
        String errorValue = Optional.ofNullable(getExceptionFromContext(context))
                .map(Throwable::getClass)
                .map(Class::getSimpleName)
                .orElse("none");
        return KeyValue.of("error", errorValue);
    }

    // 生成exception标签：取异常全类名，无异常则为"none"
    private KeyValue getExceptionKeyValue(ServerRequestObservationContext context) {
        Throwable exception = getExceptionFromContext(context);
        String exceptionValue = exception != null ? exception.getClass().getName() : "none";
        return KeyValue.of("exception", exceptionValue);
    }

    // 从上下文或请求属性中获取异常，兼容Spring Security场景
    private Throwable getExceptionFromContext(ServerRequestObservationContext context) {
        // 优先从Observation Context获取Controller抛出的异常
        if (context.getError() != null) {
            return context.getError();
        }
        // 从请求属性获取Spring Security处理的401/403等异常
        HttpServletRequest request = (HttpServletRequest) context.getCarrier();
        RequestAttributes attributes = RequestContextHolder.getRequestAttributes();
        if (attributes != null) {
            return (Throwable) attributes.getAttribute("javax.servlet.error.exception", RequestAttributes.SCOPE_REQUEST);
        }
        return (Throwable) request.getAttribute("javax.servlet.error.exception");
    }
}

2. 注册自定义Convention为Bean #

在配置类中注册该Bean，Spring Boot会自动替换默认的ServerRequestObservationConvention实现：

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.server.observation.ServerRequestObservationConvention;

@Configuration
public class MetricsConfig {

    @Bean
    public ServerRequestObservationConvention legacyServerRequestObservationConvention() {
        return new LegacyServerRequestObservationConvention();
    }
}

方案优势 #

• 无侵入：无需修改业务代码、异常处理器或过滤器，完全基于Spring Boot扩展机制实现
• 全覆盖：同时处理Controller业务异常和Spring Security拦截的401/403异常场景
• 规范合规：遵循Micrometer Observation的官方扩展规范，避免临时方案带来的维护隐患
• 兼容性：与Spring Boot 3.x的Metrics体系完全兼容，不会影响其他指标的采集逻辑

内容的提问来源于stack exchange，提问作者AndreiM