c++ 项目使用 prometheus + grafana 进行实时监控

监控指标设置

使用 prometheus-cpp 进行监控指标设置，这里以 mqtt-server 的活跃连接数为例，统计四种协议类型的活跃连接数，在接收到连接进行连接数加一，连接断开时进行连接数减一，使用 gauge 类型

cpp 复制代码

#pragma once

#include <unordered_map>

#include "metrics/IMetrics.h"

class MqttConnMetrics : public IMetrics {
public:
    void register_metrics(prometheus::Registry& registry) override {
        auto& family = prometheus::BuildGauge()
            .Name("mqtt_active_connections")
            .Help("Number of active MQTT connections")
            .Register(registry);

        protocol_gauges_ = {
            {MQTT_PROTOCOL::MQTT, &family.Add({{"protocol", "mqtt"}})},
            {MQTT_PROTOCOL::MQTTS, &family.Add({{"protocol", "mqtts"}})},
            {MQTT_PROTOCOL::WS, &family.Add({{"protocol", "ws"}})},
            {MQTT_PROTOCOL::WSS, &family.Add({{"protocol", "wss"}})}
        };

        is_registered_ = true;
    }

    void increment(MQTT_PROTOCOL protocol) {
        if (!is_registered_) return;
        protocol_gauges_[protocol]->Increment();
    }

    void decrement(MQTT_PROTOCOL protocol) {
        if (!is_registered_) return;
        protocol_gauges_[protocol]->Decrement();
    }

private:
    bool is_registered_ = false;
    std::unordered_map<MQTT_PROTOCOL, prometheus::Gauge*> protocol_gauges_;
};

开发完成后，可以通过 http://<address>:<port>/metrics 路径访问到所有的监控指标

prometheus 采集监控指标

安装好 prometheus 之后修改一下 prometheus.yml 配置中采集的目的地址

yaml 复制代码

# my global config
global:
  scrape_interval: 15s # Set the scrape interval to every 15 seconds. Default is every 1 minute.
  evaluation_interval: 15s # Evaluate rules every 15 seconds. The default is every 1 minute.
  # scrape_timeout is set to the global default (10s).

# Alertmanager configuration
alerting:
  alertmanagers:
    - static_configs:
        - targets:
          # - alertmanager:9093

# Load rules once and periodically evaluate them according to the global 'evaluation_interval'.
rule_files:
  # - "first_rules.yml"
  # - "second_rules.yml"

# A scrape configuration containing exactly one endpoint to scrape:
# Here it's Prometheus itself.
scrape_configs:
  # The job name is added as a label `job=<job_name>` to any timeseries scraped from this config.
  - job_name: "mqtt-server"
    scrape_interval: 1s
    # metrics_path defaults to '/metrics'
    # scheme defaults to 'http'.

    static_configs:
      - targets: ["localhost:8085"]

启动后访问 prometheus 界面，检查是否成功采集到，默认地址 http://localhost:9090

grafana 展示监控数据

安装完 grafana 之后，进入界面添加 prometheus 数据源，然后新增仪表盘，配置监控指标等