Prometheus 无法提取配置的指标

Question

我配置了 prometheus.yml 文件

# 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).

# Attach these labels to any time series or alerts when communicating with
# external systems (federation, remote storage, Alertmanager).
external_labels:
monitor: 'codelab-monitor'

# A scrape configuration containing exactly one endpoint to scrape:
# Here it's Prometheus itself.
scrape_configs:
- job_name:       'example-random'

# Override the global default and scrape targets from this job every 5 seconds.
scrape_interval: 5s

static_configs:
  - targets: ['localhost:8090']
    labels:
      group: 'dummy'

并向 prometheus 注册了一个指标

public class PrometheusMetricsServlet extends MetricsServlet {

private static final Gauge emailCount = Gauge.build().name("email_count")
        .help("Number of emails sent by the user")
        .register();



@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    resp.setStatus(200);
    emailCount.set(54);
 }
}

然后在web.xml

中配置了一个servlet

<servlet>
    <servlet-name>PrometheusServlet</servlet-name>
    <servlet-class>prometheusSpike.PrometheusMetricsServlet</servlet-class>
    <load-on-startup>1</load-on-startup>
</servlet>

<servlet-mapping>
    <servlet-name>PrometheusServlet</servlet-name>
    <url-pattern>/metrics</url-pattern>
</servlet-mapping>

目标的状态显示 UP，最后一次抓取发生在几秒钟前，但该指标未反映在 prometheus 中。

如何才能让 prometheus 从目标中提取配置的指标？

Answer 1

当您覆盖 doGet 时，您阻止了公开指标的代码运行。按原样使用 MetricsServlet，您将看到您的指标。

Prometheus 无法提取配置的指标

Prometheus not able to pull configured metrics

java

prometheus