Prometheus

重要

Prometheus 是开源的监控和警报工具套件，适用于微服务、容器和动态计算环境，在 Kubernetes 等容器编排平台的社区中非常流行。

• https://prometheus.io

architecture

指标类型（Metric Types）

• https://prometheus.io/docs/concepts/metric_types/ 指标介绍
• Java 集成 Prometheus，参考这篇。

计数器（Counter）

import io.prometheus.client.Counter;
class YourClass {
  static final Counter requests = Counter.build()
     .name("requests_total").help("Total requests.").register();

  void processRequest() {
    requests.inc();
    // Your code here.
  }
}

计量器（Gauge）

计量器，可增可减，可升可降。

一般用于：

• 监测并发请求数量
• 监测CPU使用率
• 监测JVM线程数量等

class YourClass {
  static final Gauge inprogressRequests = Gauge.build()
     .name("inprogress_requests").help("Inprogress requests.").register();

  void processRequest() {
    inprogressRequests.inc();
    // Your code here.
    inprogressRequests.dec();
  }
}

摘要（Summary）

class YourClass {
  static final Summary receivedBytes = Summary.build()
     .name("requests_size_bytes").help("Request size in bytes.").register();
  static final Summary requestLatency = Summary.build()
     .name("requests_latency_seconds").help("Request latency in seconds.").register();

  void processRequest(Request req) {
    Summary.Timer requestTimer = requestLatency.startTimer();
    try {
      // Your code here.
    } finally {
      receivedBytes.observe(req.size());
      requestTimer.observeDuration();
    }
  }
}

直方图（Histogram）

class YourClass {
  static final Histogram requestLatency = Histogram.build()
     .name("requests_latency_seconds").help("Request latency in seconds.").register();

  void processRequest(Request req) {
    Histogram.Timer requestTimer = requestLatency.startTimer();
    try {
      // Your code here.
    } finally {
      requestTimer.observeDuration();
    }
  }
}

命名规范

• https://prometheus.io/docs/practices/naming/ 命名规范最佳实践