使用Prometheus检测Java应用程序

2019年7月28日 329次阅读

我正在尝试使用prometheus
java客户端库监控
Java应用程序中的多个指标,但我一次难以监控多个指标.如果我只注册并抓取一个指标,一切似乎工作正常,我可以使用prometheus应用程序查看指标,但如果我尝试公开和监控多个指标,那么只有一个指标可见.

所以如果我有一个带有检测类的应用程序,如下所示

package com.telemetryserver.Instrumentation;

import io.prometheus.client.*;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

public class Instrumented_Class extends HttpServlet
{
    private static Instrumented_Class _instance = null;

    public static final Gauge metric_1 = Gauge.build().name("metric_1").help("metric_1").register();
    //public static final Gauge metric_2 = Gauge.build().name("metric_2").help("metric_2").register();

    public static Instrumented_Class getInstance()
    {
        if (_instance == null)
            _instance = new Instrumented_Class();

        return _instance;
    }

    //Getters and Setters

    public static void setMetric_1(double val) { metric_1.set(val); }

    public static double getMetric_1() { return metric_1.get(); }

    //public static void setMetric_2(double val) { metric_2.set(val); }

    //public static double getMetric_2() { return metric_2.get(); }

    @Override
    protected void doGet(final HttpServletRequest req, final HttpServletResponse resp) throws ServletException, IOException
    {

        double metric_1 = Instrumented_Class.getMetric_1();
        Instrumented_Class.setMetric_1(metric_1 + 1);

        //double metric_2 = Instrumented_Class.getMetric_2();
        //Instrumented_Class.setMetric_2(metric_2 + 2);

        resp.getWriter().println("Hello from Instrumented_Class!!!," +
                " metric_1 = " + metric_1
                //+ " metric_2 = " + metric_2
        );
    }
}

和主要班级一样

package com.telemetryserver.client;


import com.telemetryserver.Instrumentation.*;
import io.prometheus.client.exporter.MetricsServlet;
import io.prometheus.client.hotspot.DefaultExports;
import org.eclipse.jetty.server.Server;
import org.eclipse.jetty.servlet.ServletContextHandler;
import org.eclipse.jetty.servlet.ServletHolder;

public class TelemetryApp
{
    public static void main(String[] args)
    {
        startTestServer(2018);
    }


    public static void startTestServer(int port)
    {
        try
        {
            Server server = new Server(port);
            ServletContextHandler context = new ServletContextHandler();
            context.setContextPath("/");
            server.setHandler(context);

            //Expose our Instrumented servlet.
            context.addServlet(new ServletHolder(Instrumented_Class.getInstance()), "/");

            //Prometheus Metrics Servlet
            context.addServlet(new ServletHolder(new MetricsServlet()), "/metrics");

            // Add metrics about CPU, JVM memory etc.
            //DefaultExports.initialize();

            // Start the webserver.
            server.start();
            server.join();
        }
        catch (Exception ex)
        {
            ex.printStackTrace();
        }
    }
 }

并且还使用YAML文件

global:
  scrape_interval:     2s # Set the scrape interval to every 15 seconds. Default is every 1 minute.
  evaluation_interval: 2s # 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: 'telemetryserver'

    metrics_path : '/metrics'
    # scheme defaults to 'http'.

    static_configs:
    - targets: ['localhost:2018']

我可以通过运行prometheus然后运行查询“metric_1”来监控指标“metric_1”.这一切都没问题,但如果我通过取消注释已检测类中的行来添加另一个名为metric_2的指标,则metric_2会显示prometheus但metric_1会停止显示.此外,如果我取消注释DefaultExports.initialize(); line(添加了所有默认的prometheus指标),然后metric_1和metric_2都停止显示,只显示名为“jvm_threads_current”的默认指标.

有人可以请教我如何监控prometheus中的多个指标吗？任何帮助赞赏.

最佳答案 你的申请没问题.

只需确保通过点击/ ​​metrics端点进行测试.这就是prometheus从您的应用程序中收集指标的方式.

当我在本地测试它时,使用指标和导出JVM指标,我有一个类似于这个的输出：

*** lots of jvm metrics
jvm_gc_collection_seconds_count{gc="PS MarkSweep",} 0.0
jvm_gc_collection_seconds_sum{gc="PS MarkSweep",} 0.0
# HELP metric_2 metric_2
# TYPE metric_2 gauge
metric_2 12.0
# HELP metric_1 metric_1
# TYPE metric_1 gauge
metric_1 6.0
# HELP jvm_threads_current Current thread count of a JVM
# TYPE jvm_threads_current gauge
jvm_threads_current 16.0

其中包含您的自定义指标以及来自JVM的指标.

您的Prometheus配置也可以.要测试集成,请转到“状态”>“目标”,您应该在下面的图像中看到您的服务：

《使用Prometheus检测Java应用程序》

然后转到“图形”页面并输入表达式{job =“telemetryserver”}以检查Prometheus是否实际上正在从您的应用程序中收集指标.你应该看到类似的东西：

《使用Prometheus检测Java应用程序》

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