微服务的监控链路的分析（一）

在微服务系统中统计API QPS，需要采用分布式环境下的监控策略。以下是几种高效可靠的实现方案：

一、架构级方案（推荐）

1. API网关统一监控

graph LR
    Client -->|请求| Gateway[API网关]
    Gateway -->|路由| ServiceA[服务A]
    Gateway -->|路由| ServiceB[服务B]
    Gateway -->|指标上报| Prometheus
    Prometheus --> Grafana

‌实现步骤‌：

// Spring Cloud Gateway 配置
@Bean
public RouteLocator customRouteLocator(RouteLocatorBuilder builder, MeterRegistry registry) {
    return builder.routes()
        .route("service_a", r -> r.path("/api/a/**")
            .filters(f -> f.filter(new MetricsFilter(registry, "service_a")))
            .uri("lb://SERVICE-A"))
        .route("service_b", r -> r.path("/api/b/**")
            .filters(f -> f.filter(new MetricsFilter(registry, "service_b")))
            .uri("lb://SERVICE-B"))
        .build();
}

// 自定义指标过滤器
public class MetricsFilter implements GatewayFilter {
    private final Counter counter;
    
    public MetricsFilter(MeterRegistry registry, String serviceName) {
        this.counter = Counter.builder("api_requests")
            .tag("service", serviceName)
            .register(registry);
    }

    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        counter.increment();
        return chain.filter(exchange);
    }
}

2. 服务网格监控（如Istio）

# PromQL查询服务QPS sum(rate(istio_requests_total{reporter="destination"}[1m])) by (destination_service, destination_workload)

二、代码级集成方案

1. Spring Boot Actuator + Micrometer

# application.yml
management:
  endpoints:
    web:
      exposure:
        include: promethe