Spring Boot整合 Prometheus

Micrometer簡介

Micrometer 為 Java 平臺(tái)上的性能數(shù)據(jù)收集提供了一個(gè)通用的 API，應(yīng)用程序只需要使用 Micrometer 的通用 API 來收集性能指標(biāo)即可。Micrometer 會(huì)負(fù)責(zé)完成與不同監(jiān)控系統(tǒng)的適配工作。這就使得切換監(jiān)控系統(tǒng)變得很容易。Micrometer 還支持推送數(shù)據(jù)到多個(gè)不同的監(jiān)控系統(tǒng)。Micrometer類似日志系統(tǒng)中SLF4J。

Micrometer中有兩個(gè)最核心的概念，分別是是計(jì)量器(Meter)和計(jì)量器注冊(cè)表(MeterRegistry),下面來分別看下這兩個(gè)概念。

計(jì)量器(Meter)

Meter用來收集性能指標(biāo)數(shù)據(jù)(Metris)，總共有四種類型的Meter，分別是Counter，Gauge，Timer，Summary。

每個(gè)Meter都有自己的名稱，同時(shí)Meter可以指定一系列的tag。tag是以key-value的形式出現(xiàn)，這樣我們就可以根據(jù)tag對(duì)指標(biāo)進(jìn)行過濾。除了每個(gè)Meter獨(dú)有的標(biāo)簽外，也可以通過MeterRegistry添加通用的tag。

MeterRegistry.Config config = simpleMeterRegistry.config();
    config.commonTags("tag1","value1","tag2","value2");

Counter

Counter只允許增加值，Counter所表示的計(jì)數(shù)值是double類型，默認(rèn)情況下增加的值是1.0

@Autowired
private SimpleMeterRegistry simpleMeterRegistry;

@Bean
public Counter counter1(){
    return Counter.builder("test.count1").register(simpleMeterRegistry);
}

@Bean
public Counter counter2(){
    return simpleMeterRegistry.counter("test.count2");
}

@Test
public void test(){
    counter1.increment();
}

Gauge

Cauge是表示單個(gè)的變化的值，例如溫度，氣壓。與Counter的區(qū)別在于，Gauge的值不總是增加的

public void guage(){
    Gauge.builder("guaua1", this::getValue).register(simpleMeterRegistry);
}

public double getValue(){
    return ThreadLocalRandom.current().nextDouble();
}

Gauge對(duì)象一旦被創(chuàng)建，就不能手動(dòng)對(duì)其中的值進(jìn)行修改。在每次取樣時(shí)，Gauge 會(huì)返回當(dāng)前值

Timer

Timer通常用來記錄事件的持續(xù)時(shí)間。Timer會(huì)記錄兩類的數(shù)據(jù)，事件的數(shù)量和總的持續(xù)時(shí)間。Timer提供了不同方式來記錄持續(xù)時(shí)間。第一種方式是使用record()方法來記錄Runnable和Callable對(duì)象的運(yùn)行時(shí)間，第二種方式是使用Timer.Sample來保存計(jì)時(shí)狀態(tài)

public void record(){
    Timer timer = simpleMeterRegistry.timer("record");
    timer.record(() -> {
        try {
            Thread.sleep(3000);
        }catch (Exception e){
            e.printStackTrace();
        }
    });
}

public void sample(){
    Timer.Sample sample = Timer.start();
    new Thread(()->{
        try {
            Thread.sleep(3000);
        }catch (Exception e){
            e.printStackTrace();
        }
        sample.stop(simpleMeterRegistry.timer("sample"));
    });
}

summary

summary用來記錄指標(biāo)的分布，summary根據(jù)每個(gè)指標(biāo)的值，把值分配到對(duì)應(yīng)的bucket中。Micrometer默認(rèn)的bucket的值從1到Long.MAX_VALUE，可以通過minimumExpectedValue和maximumExpectedValue來控制bucket的范圍，如果指標(biāo)的值較小，還可以通過scale來設(shè)置一個(gè)值對(duì)數(shù)值進(jìn)行放大

public void summary(){
    DistributionSummary summary = DistributionSummary.builder("summary")
            .maximumExpectedValue(10L)
            .minimumExpectedValue(1L)
            .publishPercentiles(0.5, 0.75, 0.9)
            .register(simpleMeterRegistry);

    summary.record(1.0);
    summary.record(5.0);
    summary.record(4.5);
    summary.record(3.0);

    System.out.println(summary.takeSnapshot());
}

計(jì)量器注冊(cè)表(MeterRegistry)

MeterRegistry負(fù)責(zé)創(chuàng)建和維護(hù)Meter。每一個(gè)監(jiān)控系統(tǒng)有自己獨(dú)有的registry

其中SimpleMeterRegistry是一個(gè)基于內(nèi)存的注冊(cè)表，它不支持導(dǎo)出數(shù)據(jù)到監(jiān)控系統(tǒng)，主要用來進(jìn)行本地開發(fā)和測(cè)試。

Micrometer支持多個(gè)不同的監(jiān)控系統(tǒng)，通過CompositeMeterRegistry可以把多個(gè)計(jì)量器注冊(cè)表組合起來，從而允許同時(shí)發(fā)布數(shù)據(jù)到多個(gè)監(jiān)控系統(tǒng)中。

public void compositeRegistry(){
        CompositeMeterRegistry compositeMeterRegistry = new CompositeMeterRegistry();
        compositeMeterRegistry.add(new SimpleMeterRegistry());
        compositeMeterRegistry.add(new SimpleMeterRegistry(new SimpleConfig() {
            @Override
            public String get(String s) {
                return null;
            }

            //增加前綴
            @Override
            public String prefix() {
                return "simple";
            }
        },Clock.SYSTEM));

        Counter counter = compositeMeterRegistry.counter("test");
        counter.increment();
    }

Micrometer本身提供了一個(gè)靜態(tài)的全局注冊(cè)表Metrics.golbalRegistry。這個(gè)注冊(cè)表一個(gè)組合注冊(cè)表，使用Metrics類中的靜態(tài)方法創(chuàng)建的計(jì)量器，都會(huì)被添加到這個(gè)全局注冊(cè)表中

public void globalRegistry(){
    Metrics.addRegistry(simpleMeterRegistry);
    Counter global = Metrics.counter("global");
    global.increment();
}

SpringBoot Actuator

上述介紹了Micrometer的一些簡單使用，從Spring Boot2.0開始，Micrometer就是Spring Boot默認(rèn)提供的性能指標(biāo)收集庫。SpringBoot Actuator提供了對(duì)Micrometer的自動(dòng)配置。在項(xiàng)目中引入SpringBoot Actuator，

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-actuator</artifactId>
</dependency>

并在配置文件中，增加如下配置

Actuator可對(duì)外默認(rèn)的服務(wù)，*表示顯示所有
management.endpoints.web.exposure.include=*

啟動(dòng)項(xiàng)目，訪問http://8080/actuator,就可以看到Actuator提供的所有監(jiān)控

{
  "_links": {
    "self": {
      "href": "http://localhost:8080/actuator",
      "templated": false
    },
    "auditevents": {
      "href": "http://localhost:8080/actuator/auditevents",
      "templated": false
    },
    "beans": {
      "href": "http://localhost:8080/actuator/beans",
      "templated": false
    },
    "caches-cache": {
      "href": "http://localhost:8080/actuator/caches/{cache}",
      "templated": true
    },
    "caches": {
      "href": "http://localhost:8080/actuator/caches",
      "templated": false
    },
    "health": {
      "href": "http://localhost:8080/actuator/health",
      "templated": false
    },
    "health-component": {
      "href": "http://localhost:8080/actuator/health/{component}",
      "templated": true
    },
    "health-component-instance": {
      "href": "http://localhost:8080/actuator/health/{component}/{instance}",
      "templated": true
    },
    "conditions": {
      "href": "http://localhost:8080/actuator/conditions",
      "templated": false
    },
    "configprops": {
      "href": "http://localhost:8080/actuator/configprops",
      "templated": false
    },
    "env": {
      "href": "http://localhost:8080/actuator/env",
      "templated": false
    },
    "env-toMatch": {
      "href": "http://localhost:8080/actuator/env/{toMatch}",
      "templated": true
    },
    "info": {
      "href": "http://localhost:8080/actuator/info",
      "templated": false
    },
    "loggers": {
      "href": "http://localhost:8080/actuator/loggers",
      "templated": false
    },
    "loggers-name": {
      "href": "http://localhost:8080/actuator/loggers/{name}",
      "templated": true
    },
    "heapdump": {
      "href": "http://localhost:8080/actuator/heapdump",
      "templated": false
    },
    "threaddump": {
      "href": "http://localhost:8080/actuator/threaddump",
      "templated": false
    },
    "prometheus": {
      "href": "http://localhost:8080/actuator/prometheus",
      "templated": false
    },
    "metrics": {
      "href": "http://localhost:8080/actuator/metrics",
      "templated": false
    },
    "metrics-requiredMetricName": {
      "href": "http://localhost:8080/actuator/metrics/{requiredMetricName}",
      "templated": true
    },
    "scheduledtasks": {
      "href": "http://localhost:8080/actuator/scheduledtasks",
      "templated": false
    },
    "httptrace": {
      "href": "http://localhost:8080/actuator/httptrace",
      "templated": false
    },
    "mappings": {
      "href": "http://localhost:8080/actuator/mappings",
      "templated": false
    }
  }
}

訪問http://localhost:8080/actuator/metrics，可以看到Actuator默認(rèn)收集的監(jiān)控指標(biāo)，包括JVM相關(guān)指標(biāo)(內(nèi)存使用，垃圾收集)，tomcat相關(guān)指標(biāo)，數(shù)據(jù)庫連接池還是系統(tǒng)相關(guān)指標(biāo)

{
  "names": [
    "jvm.memory.max",
    "jvm.threads.states",
    "process.files.max",
    "jvm.gc.memory.promoted",
    "system.load.average.1m",
    "jvm.memory.used",
    "jvm.gc.max.data.size",
    "jvm.gc.pause",
    "jvm.memory.committed",
    "system.cpu.count",
    "logback.events",
    "tomcat.global.sent",
    "jvm.buffer.memory.used",
    "tomcat.sessions.created",
    "jvm.threads.daemon",
    "system.cpu.usage",
    "jvm.gc.memory.allocated",
    "tomcat.global.request.max",
    "tomcat.global.request",
    "tomcat.sessions.expired",
    "jvm.threads.live",
    "jvm.threads.peak",
    "tomcat.global.received",
    "process.uptime",
    "tomcat.sessions.rejected",
    "process.cpu.usage",
    "http.server.requests",
    "tomcat.threads.config.max",
    "jvm.classes.loaded",
    "jvm.classes.unloaded",
    "tomcat.global.error",
    "tomcat.sessions.active.current",
    "tomcat.sessions.alive.max",
    "jvm.gc.live.data.size",
    "tomcat.threads.current",
    "process.files.open",
    "jvm.buffer.count",
    "jvm.buffer.total.capacity",
    "tomcat.sessions.active.max",
    "tomcat.threads.busy",
    "process.start.time"
  ]
}

我們可以通過以下鏈接來查看具體某個(gè)指標(biāo)

http://localhost:8080/actuator/metrics/metricName

其中metricName為需要查看指標(biāo)的名稱，例如查看jvm內(nèi)存

 http://localhost:8080/actuator/metrics/jvm.memory.used

從上圖中我們可以看到j(luò)vm.memory.used有兩個(gè)tag，area和id，area指定內(nèi)存位置(堆內(nèi)存和非堆內(nèi)存)，id指定內(nèi)存分類，我們可以指定tag來查看更細(xì)致的指標(biāo)

http://localhost:8080/actuator/metrics/jvm.memory.used?tag=area:heap
http://localhost:8080/actuator/metrics/jvm.memory.used?tag=area:heap&tag=id:PS%20Eden%20Space

Prometheus

Micrometer支持Prometheus，Micrometer提供PrometheusMeterRegistry注冊(cè)表，用于將指標(biāo)轉(zhuǎn)為Prometheus格式的指標(biāo)。首先需要在pom文件引入依賴

<dependency>
    <groupId>io.micrometer</groupId>
    <artifactId>micrometer-registry-prometheus</artifactId>
</dependency>

其次在配置文件中，配置暴露Prometheus，并允許將指標(biāo)導(dǎo)入到Prometheus中

management.endpoint.prometheus.enabled=true
management.metrics.export.prometheus.enabled=true

項(xiàng)目啟動(dòng)后，我們?cè)L問http://localhost:8080/actuator/prometheus，可以看到指標(biāo)以變成Prometheus格式的指標(biāo)

可以安裝Prometheus來采集這些指標(biāo)

docker run -d -p 9090:9090 -v ~/Documents/config/prometheus.yml:/etc/prometheus/prometheus.yml prom/prometheus

其中prometheus.yml配置了采集地址及路徑

scrape_configs:
 - job_name: prometheus-test
   metrics_path: /actuator/prometheus
   static_configs:
   - targets: ['172.16.22.50:8080']

172.16.22.50是我本機(jī)的地址，你們可以修改為自己的ip地址即可，訪問http://localhost:9090/targets可以看到Prometheus采集配置

自定義Metric

我們可以利用Prometheus client自定義metric

package com.wbl.spingbootdemo.prometheus;

import io.prometheus.client.CollectorRegistry;
import io.prometheus.client.Counter;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import javax.annotation.PostConstruct;

/**
 * @author wbl
 * @date 2019-09-29
 */
@Service
public class PrometheusMeter {

    @Autowired
    private CollectorRegistry collectorRegistry;

    // 定義name為prometheus_counter的counter
    public Counter prometheusCounter(){
        return Counter.build().name("prometheus_counter").help("prometheus counter test")
                .register(collectorRegistry);
    }

    @PostConstruct
    public void init(){
        Counter counter = prometheusCounter();
        new Thread(()-> {
            while (true){
                counter.inc();
                try {
                    Thread.sleep(5000);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }).start();
    }
}

啟動(dòng)項(xiàng)目之后，可以在Prometheus查詢頁面看到剛剛定義的指標(biāo)prometheus_counter

總結(jié)

1. Micrometer整合了多個(gè)監(jiān)控系統(tǒng)，包括Prometheus。Micrometer利用Meter收集數(shù)據(jù)，利用不同的MeterRegistry與不同的監(jiān)控系統(tǒng)整合

2. SpringBoot Actuator集成了Micrometer，定義了許多默認(rèn)的metric，可以在http://localhost:8080/actuator/metrics查看

3. SpringBoot Actuator可以通過Micrometer將采集的指標(biāo)導(dǎo)入到Prometheus中

參考文獻(xiàn)

• Micrometer

• Quick Guide to Micrometer

• Instrumenting And Monitoring Spring Boot 2 Applications

• 自定義Metrics：讓Prometheus監(jiān)控你的應(yīng)用程序

• 使用 Micrometer 記錄 Java 應(yīng)用性能指標(biāo)

喜歡，在看