如何从java应用程序导出Prometheus格式的度量(由DropWizard收集)？

Question

My aim -创建spring引导应用程序，使用DropWizard收集度量，并为Prometheus公开端点以使用应用程序度量：

我的代码：

@SpringBootApplication
@EnableMetrics(proxyTargetClass = true)
public class DemoApplication {

    public static void main(String[] args) {

        SpringApplication.run(DemoApplication.class, args);
    }

}

package com.example.demo;

import com.codahale.metrics.Counter;
import com.codahale.metrics.MetricRegistry;
import com.codahale.metrics.annotation.Timed;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

import javax.annotation.PostConstruct;
import java.util.concurrent.atomic.AtomicLong;

@RestController
public class HelloController {
    private AtomicLong atomicLong = new AtomicLong();
    private Counter counter;

    @Autowired
    private MetricRegistry metricRegistry;

    @PostConstruct
    public void init() {
        counter = metricRegistry.counter("counter");
    }

    @GetMapping("/hello")
    @Timed(name = "my-index")
    public String index() {
        counter.inc();

        return "Greetings from Spring Boot!. count=" + atomicLong.incrementAndGet();
    }

}

package com.example.demo;

import com.codahale.metrics.ConsoleReporter;
import com.codahale.metrics.MetricRegistry;
import com.codahale.metrics.jvm.FileDescriptorRatioGauge;
import com.codahale.metrics.jvm.GarbageCollectorMetricSet;
import com.codahale.metrics.jvm.MemoryUsageGaugeSet;
import com.codahale.metrics.jvm.ThreadStatesGaugeSet;
import com.codahale.metrics.servlets.AdminServlet;
import com.codahale.metrics.servlets.CpuProfileServlet;
import com.codahale.metrics.servlets.MetricsServlet;
import com.ryantenney.metrics.spring.config.annotation.EnableMetrics;
import com.ryantenney.metrics.spring.config.annotation.MetricsConfigurerAdapter;
import io.prometheus.client.dropwizard.DropwizardExports;
import org.springframework.boot.web.servlet.ServletRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import java.util.concurrent.TimeUnit;

@Configuration
public class Config /*extends MetricsConfigurerAdapter*/ {
    //@Override
            //public void configureReporters(MetricRegistry metricRegistry) {
        //    // registerReporter allows the MetricsConfigurerAdapter to
        //    // shut down the reporter when the Spring context is closed
        //   // registerReporter(ConsoleReporter
        //   //         .forRegistry(metricRegistry)
        //   //         .build())
        //   //         .start(1, TimeUnit.MINUTES);


        //    new DropwizardExports(metricRegistry).register();
        //}

   @Bean
   public DropwizardExports dropwizardExports(MetricRegistry metricRegistry){
       DropwizardExports dropwizardExports = new DropwizardExports(metricRegistry);
       dropwizardExports.register();
       return dropwizardExports;
   }

    @Bean
    public MetricRegistry metricRegistry() {
        MetricRegistry metricRegistry = new MetricRegistry();
        metricRegistry.registerAll(new GarbageCollectorMetricSet());
        metricRegistry.registerAll(new MemoryUsageGaugeSet());
        metricRegistry.registerAll(new ThreadStatesGaugeSet());
        return metricRegistry;
    }

    @Bean
    public ConsoleReporter consoleReporter(MetricRegistry metricRegistry) {
        ConsoleReporter reporter = ConsoleReporter.forRegistry(metricRegistry).build();
        reporter.start(5, TimeUnit.SECONDS);
        reporter.report();
        return reporter;
    }

    @Bean
    public ServletRegistrationBean<MetricsServlet> registerMetricsServlet(MetricRegistry metricRegistry) {
        return new ServletRegistrationBean<>(new MetricsServlet(metricRegistry), "/metrics/*");
    }

    @Bean
    public ServletRegistrationBean<CpuProfileServlet> registerCpuServlet() {
        return new ServletRegistrationBean<>(new CpuProfileServlet(), "/cpu/*");
    }
}

build.gradle:

plugins {
    id 'org.springframework.boot' version '2.7.1'
    id 'io.spring.dependency-management' version '1.0.11.RELEASE'
    id 'java'
}

group = 'com.example'
version = '0.0.1-SNAPSHOT'
sourceCompatibility = '17'

repositories {
    mavenCentral()
}

dependencies {
    implementation 'org.springframework.boot:spring-boot-starter-web'
    implementation "org.springframework.boot:spring-boot-starter-actuator"
    // Minimum required for metrics.
    implementation ('com.ryantenney.metrics:metrics-spring:3.1.3') {
        exclude group: 'com.codahale.metrics'
        exclude group: 'org.springframework'
    }
    implementation 'io.dropwizard.metrics:metrics-core:4.2.9'
    implementation 'io.dropwizard.metrics:metrics-annotation:4.2.9'
    implementation 'io.dropwizard.metrics:metrics-servlets:4.2.9'

    implementation 'io.prometheus:simpleclient_dropwizard:0.15.0'
    implementation 'io.prometheus:simpleclient_servlet:0.15.0'
    implementation 'io.dropwizard:dropwizard-core:2.1.0'

    implementation 'com.ryantenney.metrics:metrics-spring:3.1.3'
    implementation 'io.prometheus:simpleclient_common:0.16.0'

    testImplementation 'org.springframework.boot:spring-boot-starter-test'
}

tasks.named('test') {
    useJUnitPlatform()
}

我访问localhost:8080/metrics并收到以下响应：

{
  "version": "4.0.0",
  "gauges": {
    "G1-Old-Generation.count": {
      "value": 0
    },
    "G1-Old-Generation.time": {
      "value": 0
    },
    "G1-Young-Generation.count": {
      "value": 7
    },
    "G1-Young-Generation.time": {
      "value": 31
    },
    "blocked.count": {
      "value": 0
    },
    "count": {
      "value": 26
    },
    "daemon.count": {
      "value": 22
    },
    "deadlock.count": {
      "value": 0
    },
    "deadlocks": {
      "value": []
    },
    "heap.committed": {
      "value": 301989888
    },
    "heap.init": {
      "value": 532676608
    },
    "heap.max": {
      "value": 8518631424
    },
    "heap.usage": {
      "value": 0.008041180864688155
    },
    "heap.used": {
      "value": 68499856
    },
    "new.count": {
      "value": 0
    },
    "non-heap.committed": {
      "value": 51707904
    },
    "non-heap.init": {
      "value": 2555904
    },
    "non-heap.max": {
      "value": -1
    },
    "non-heap.usage": {
      "value": -5.0738536E7
    },
    "non-heap.used": {
      "value": 50738536
    },
    "peak.count": {
      "value": 32
    },
    "pools.CodeCache.committed": {
      "value": 10551296
    },
    "pools.CodeCache.init": {
      "value": 2555904
    },
    "pools.CodeCache.max": {
      "value": 50331648
    },
    "pools.CodeCache.usage": {
      "value": 0.2039642333984375
    },
    "pools.CodeCache.used": {
      "value": 10265856
    },
    "pools.Compressed-Class-Space.committed": {
      "value": 5177344
    },
    "pools.Compressed-Class-Space.init": {
      "value": 0
    },
    "pools.Compressed-Class-Space.max": {
      "value": 1073741824
    },
    "pools.Compressed-Class-Space.usage": {
      "value": 0.004625104367733002
    },
    "pools.Compressed-Class-Space.used": {
      "value": 4966168
    },
    "pools.G1-Eden-Space.committed": {
      "value": 188743680
    },
    "pools.G1-Eden-Space.init": {
      "value": 29360128
    },
    "pools.G1-Eden-Space.max": {
      "value": -1
    },
    "pools.G1-Eden-Space.usage": {
      "value": 0.26666666666666666
    },
    "pools.G1-Eden-Space.used": {
      "value": 50331648
    },
    "pools.G1-Eden-Space.used-after-gc": {
      "value": 0
    },
    "pools.G1-Old-Gen.committed": {
      "value": 109051904
    },
    "pools.G1-Old-Gen.init": {
      "value": 503316480
    },
    "pools.G1-Old-Gen.max": {
      "value": 8518631424
    },
    "pools.G1-Old-Gen.usage": {
      "value": 0.0017806278080379123
    },
    "pools.G1-Old-Gen.used": {
      "value": 15168512
    },
    "pools.G1-Old-Gen.used-after-gc": {
      "value": 15168512
    },
    "pools.G1-Survivor-Space.committed": {
      "value": 4194304
    },
    "pools.G1-Survivor-Space.init": {
      "value": 0
    },
    "pools.G1-Survivor-Space.max": {
      "value": -1
    },
    "pools.G1-Survivor-Space.usage": {
      "value": 0.7151832580566406
    },
    "pools.G1-Survivor-Space.used": {
      "value": 2999696
    },
    "pools.G1-Survivor-Space.used-after-gc": {
      "value": 2999696
    },
    "pools.Metaspace.committed": {
      "value": 35979264
    },
    "pools.Metaspace.init": {
      "value": 0
    },
    "pools.Metaspace.max": {
      "value": -1
    },
    "pools.Metaspace.usage": {
      "value": 0.9868604316086066
    },
    "pools.Metaspace.used": {
      "value": 35506512
    },
    "runnable.count": {
      "value": 10
    },
    "terminated.count": {
      "value": 0
    },
    "timed_waiting.count": {
      "value": 5
    },
    "total.committed": {
      "value": 353697792
    },
    "total.init": {
      "value": 535232512
    },
    "total.max": {
      "value": 8518631423
    },
    "total.used": {
      "value": 119238392
    },
    "total_started.count": {
      "value": 47
    },
    "waiting.count": {
      "value": 11
    }
  },
  "counters": {
    "counter": {
      "count": 9
    }
  },
  "histograms": {},
  "meters": {},
  "timers": {}
}

显然，这个输出不适用于普罗米修斯(所有的点至少应该用"_“替换)

如何使输出的格式为prometheus做好准备？

附注：

基于文档，我理解io.prometheus.client.dropwizardDropwizardExports类负责生成格式为Prometheus的度量，但我不明白如何生成。

Answer 1

最后，我找到了一个根本原因：

com.codahale.metrics.servlets.MetricsServlet

应改为

io.prometheus.client.exporter.MetricsServlet

Answer 2

我实现了将度量导出到Prometheus的不同方法：

1.1) Pushgateway的自定义实现

我编写了将输出生成到StringBuilder中的代码，并只遵循文档格式/

最后，使用您选择的java HttpClient将该字符串发布到Pushgateway。

1.2)由Prometheus刮除的自定义页面

我编写了一个动态页面(servlet，jsp，.)生成带有纯文本内容类型的输出，并且只遵循文档格式/

配置Prometheus以抓取该动态页面。

1. 使用现有图书馆

我使用了java，它是Java的官方客户端库。查看自述中关于导出的章节，它非常好，并且涵盖了推送度量和被刮掉的两个方面。

Answer 3

我看不出有什么明显的区别，但这是一个有用的例子：

public class JavaDropwizard {
  // Create registry for Dropwizard metrics.
  static final MetricRegistry metrics = new MetricRegistry();
  // Create a Dropwizard counter.
  static final Counter counter = metrics.counter("my.example.counter.total");

  public static void main( String[] args ) throws Exception {
      // Increment the counter.
      counter.inc();

      // Hook the Dropwizard registry into the Prometheus registry
      // via the DropwizardExports collector.
      CollectorRegistry.defaultRegistry.register(new DropwizardExports(metrics));


      // Expose Prometheus metrics.
      Server server = new Server(1234);
      ServletContextHandler context = new ServletContextHandler();
      context.setContextPath("/");
      server.setHandler(context);
      context.addServlet(new ServletHolder(new MetricsServlet()), "/metrics");
      // Add metrics about CPU, JVM memory etc.
      DefaultExports.initialize();
      // Start the webserver.
      server.start();
      server.join();
  }
}

pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>io.robustperception.java_examples</groupId>
  <artifactId>java_dropwizard</artifactId>
  <packaging>jar</packaging>
  <version>1.0-SNAPSHOT</version>
  <properties>
    <maven.compiler.source>17</maven.compiler.source>
    <maven.compiler.target>17</maven.compiler.target>
  </properties>
  <name>java_dropwizard</name>
  <url>http://maven.apache.org</url>
  <dependencies>
    <dependency>
      <groupId>io.prometheus</groupId>
      <artifactId>simpleclient</artifactId>
      <version>0.15.0</version>
    </dependency>
    <dependency>
      <groupId>io.prometheus</groupId>
      <artifactId>simpleclient_hotspot</artifactId>
      <version>0.15.0</version>
    </dependency>
    <dependency>
      <groupId>io.prometheus</groupId>
      <artifactId>simpleclient_servlet</artifactId>
      <version>0.15.0</version>
    </dependency>
    <dependency>
      <groupId>io.prometheus</groupId>
      <artifactId>simpleclient_dropwizard</artifactId>
      <version>0.15.0</version>
    </dependency>
    <dependency>
        <groupId>io.dropwizard.metrics</groupId>
        <artifactId>metrics-core</artifactId>
        <version>4.2.9</version>
    </dependency>
    <dependency>
      <groupId>org.eclipse.jetty</groupId>
      <artifactId>jetty-servlet</artifactId>
      <version>8.1.7.v20120910</version>
    </dependency>
  </dependencies>

  <build>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-compiler-plugin</artifactId>
        <version>3.1</version>
      </plugin>
      <!-- Build a full jar with dependencies --> 
      <plugin>
        <artifactId>maven-assembly-plugin</artifactId>
        <configuration>
          <archive>
        <manifest>
          <mainClass>io.robustperception.java_examples.JavaDropwizard</mainClass>
        </manifest>
      </archive>
      <descriptorRefs>
        <descriptorRef>jar-with-dependencies</descriptorRef>
      </descriptorRefs>
    </configuration>
    <executions>
      <execution>
        <id>make-assembly</id>
        <phase>package</phase>
        <goals>
          <goal>single</goal>
        </goals>
      </execution>
    </executions>
  </plugin>
</plugins>