Apache Camel 2.x迁移至3.x/4.x后路由指标兼容性问题求助

针对Camel 3.x及以上版本移除MicrometerRoutePolicyNamingStrategy.getTags(Exchange)方法后的自定义标签需求，以下是几个可行的实现方案：

方案一：自定义MicrometerMetricsService扩展指标标签 #

Camel 3.x+中，MicrometerRoutePolicy依赖MicrometerMetricsService处理指标逻辑，可通过自定义该服务的实现，在记录指标时注入Exchange相关标签：

1. 实现自定义MicrometerMetricsService，重写recordExchangeEvent方法提取所需标签：

public class CustomMicrometerMetricsService extends DefaultMicrometerMetricsService {

    public CustomMicrometerMetricsService(MeterRegistry meterRegistry, MicrometerRoutePolicyNamingStrategy namingStrategy) {
        super(meterRegistry, namingStrategy);
    }

    @Override
    public void recordExchangeEvent(Exchange exchange, String eventType, long duration) {
        // 从Exchange中获取自定义属性
        String messageName = exchange.getProperty("messageName", String.class);
        // 构建自定义标签集合
        Tags customTags = Tags.of("messageName", messageName);
        
        // 调用父类方法时传入自定义标签
        super.recordExchangeEvent(exchange, eventType, duration, customTags);
    }
}

2. 在Spring Boot配置中替换默认服务实例：

@Configuration
public class CamelMetricsConfig {

    @Bean
    public MicrometerMetricsService customMicrometerMetricsService(MeterRegistry meterRegistry, MicrometerRoutePolicyNamingStrategy namingStrategy) {
        return new CustomMicrometerMetricsService(meterRegistry, namingStrategy);
    }
}

方案二：通过EventNotifier手动上报自定义指标 #

利用Camel的事件监听机制，监听Exchange完成事件，手动向Micrometer上报带自定义标签的路由指标：

1. 实现EventNotifier监听ExchangeCompletedEvent：

public class CustomExchangeMetricsNotifier extends EventNotifierSupport {

    private final MeterRegistry meterRegistry;

    public CustomExchangeMetricsNotifier(MeterRegistry meterRegistry) {
        this.meterRegistry = meterRegistry;
    }

    @Override
    public void notify(EventObject event) throws Exception {
        if (event instanceof ExchangeCompletedEvent) {
            ExchangeCompletedEvent completedEvent = (ExchangeCompletedEvent) event;
            Exchange exchange = completedEvent.getExchange();
            Route route = exchange.getUnitOfWork().getRouteContext().getRoute();
            
            // 提取自定义标签和指标数据
            String routeId = route.getId();
            String messageName = exchange.getProperty("messageName", String.class);
            long duration = exchange.getDuration();
            
            // 上报路由耗时指标
            Timer.builder("camel.route.exchange.duration")
                    .tags("routeId", routeId, "messageName", messageName)
                    .register(meterRegistry)
                    .record(duration, TimeUnit.MILLISECONDS);
            
            // 按需上报成功/失败计数
            if (exchange.isFailed()) {
                Counter.builder("camel.route.exchange.failed")
                        .tags("routeId", routeId, "messageName", messageName)
                        .register(meterRegistry)
                        .increment();
            } else {
                Counter.builder("camel.route.exchange.success")
                        .tags("routeId", routeId, "messageName", messageName)
                        .register(meterRegistry)
                        .increment();
            }
        }
    }

    @Override
    public boolean isEnabled(EventObject event) {
        return event instanceof ExchangeCompletedEvent;
    }
}

2. 注册该EventNotifier到Camel上下文：

@Configuration
public class CamelEventConfig {

    @Bean
    public EventNotifier customExchangeMetricsNotifier(MeterRegistry meterRegistry) {
        return new CustomExchangeMetricsNotifier(meterRegistry);
    }
}

方案三：结合ThreadLocal与MeterFilter注入动态标签 #

通过ThreadLocal暂存Exchange的自定义属性，再利用Micrometer的MeterFilter全局添加标签：

1. 创建ThreadLocal工具类暂存属性：

public class ExchangeTagContext {
    private static final ThreadLocal<String> MESSAGE_NAME = new ThreadLocal<>();

    public static void setMessageName(String messageName) {
        MESSAGE_NAME.set(messageName);
    }

    public static String getMessageName() {
        return MESSAGE_NAME.get();
    }

    public static void clear() {
        MESSAGE_NAME.remove();
    }
}

2. 在路由中添加Processor存入并清理ThreadLocal：

from("direct:start")
        .process(exchange -> {
            String messageName = exchange.getProperty("messageName", String.class);
            ExchangeTagContext.setMessageName(messageName);
        })
        // 后续路由逻辑
        .to("mock:end")
        .process(exchange -> ExchangeTagContext.clear()); // 避免内存泄漏

3. 自定义MeterFilter为Camel路由指标添加标签：

public class CamelRouteTagFilter implements MeterFilter {

    @Override
    public Meter.Id map(Meter.Id id) {
        // 仅对Camel路由相关指标添加标签
        if (id.getName().startsWith("camel.route.")) {
            String messageName = ExchangeTagContext.getMessageName();
            if (messageName != null) {
                return id.withTag("messageName", messageName);
            }
        }
        return id;
    }
}

4. 注册MeterFilter到Spring Boot：

@Configuration
public class MicrometerConfig {

    @Bean
    public MeterFilter camelRouteTagFilter() {
        return new CamelRouteTagFilter();
    }
}

内容的提问来源于stack exchange，提问作者Walron