使用spring java的千分尺度量（没有Spring Boot）

Question

我是千分尺/普罗米修斯世界的新手。

另外，仅仅公开spring中的localhost:8080/metricsendpoint似乎并不能为Prometheus服务器提供任何东西。

我希望能够从我的应用程序中提取一些简单的指标，比如一些endpoint被调用了多少次，以及一些endpoint完成工作或一些数据处理需要多少时间。

Answer 1

在pom.xml中添加以下依赖项：

<dependency>
   <groupId>io.micrometer</groupId>
   <artifactId>micrometer-registry-prometheus</artifactId>
   <version>1.2.0</version>
</dependency>

下面是一个简单的测试类：

import io.micrometer.core.instrument.Counter;
import io.micrometer.core.instrument.DistributionSummary;
import io.micrometer.core.instrument.Meter;
import io.micrometer.core.instrument.Tags;
import io.micrometer.prometheus.PrometheusConfig;
import io.micrometer.prometheus.PrometheusMeterRegistry;
import org.junit.jupiter.api.Test;

public class MicrometerTest {

    private PrometheusMeterRegistry registry = new PrometheusMeterRegistry(PrometheusConfig.DEFAULT);

    @Test
    public void test() {}

//    @Test
    public void test_metrics() {
        Counter.builder("http_requests_total").description("Http Request Total").tags("method", "GET", "handler",
                "/employee", "status", "200").register(registry).increment();
        Counter.builder("http_requests_total").description("Http Request Total").tags("method", "GET", "handler",
                "/employee", "status", "200").register(registry).increment();

        DistributionSummary.builder("http_response_time_milliseconds").description("Request completed time in milliseconds")
                .tags("method", "GET", "handler", "/employee", "status", "200")
                .publishPercentiles(.5,.95,.99)
                .register(registry).record(40d);
        DistributionSummary.builder("http_response_time_milliseconds").description("Request completed time in milliseconds")
                .tags("method", "GET", "handler", "/employee", "status", "200")
                .publishPercentiles(.5,.95,.99)
                .register(registry).record(50d);

        registry.counter("http_requests_total2", "method", "GET", "status", "200").increment();
        registry.counter("http_requests_total2", "method", "Post", "status", "200").increment();
        registry.counter("http_requests_total2", "method", "GET", "status", "200").increment();

        registry.newCounter(new Meter.Id("query time", Tags.of("select query", "country"), null, "query desc", Meter.Type.COUNTER));
        System.out.println(registry.scrape());
    }
}

如果希望通过servlet公开它，请添加另一个依赖项：

<dependency>
   <groupId>javax.servlet</groupId>
   <artifactId>javax.servlet-api</artifactId>
   <version>4.0.1</version>
</dependency>

用于公开度量的示例servlet：

import com.aeris.amp.metrics.util.MeterRegistry;
import io.micrometer.core.instrument.binder.jvm.DiskSpaceMetrics;
import io.micrometer.core.instrument.binder.jvm.JvmGcMetrics;
import io.micrometer.core.instrument.binder.jvm.JvmMemoryMetrics;
import io.micrometer.core.instrument.binder.jvm.JvmThreadMetrics;
import io.micrometer.core.instrument.binder.system.ProcessorMetrics;
import io.micrometer.core.instrument.binder.system.UptimeMetrics;
import io.micrometer.prometheus.PrometheusConfig;
import io.micrometer.prometheus.PrometheusMeterRegistry;
import io.prometheus.client.exporter.common.TextFormat;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.IOException;
import java.io.Writer;

@WebServlet("/metrics")
public class MetricsServlet extends HttpServlet {

    public static PrometheusMeterRegistry registry = new PrometheusMeterRegistry(PrometheusConfig.DEFAULT);

    public void init() {
        new JvmThreadMetrics().bindTo(registry);
        new JvmGcMetrics().bindTo(registry);
        new JvmMemoryMetrics().bindTo(registry);
        new DiskSpaceMetrics(new File("/")).bindTo(registry);
        new ProcessorMetrics().bindTo(registry); // metrics related to the CPU stats
        new UptimeMetrics().bindTo(registry);
    }

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

        resp.setStatus(HttpServletResponse.SC_OK);
        resp.setContentType(TextFormat.CONTENT_TYPE_004);

        Writer writer = resp.getWriter();
        try {
            registry.scrape(writer);
            writer.flush();
        } finally {
            writer.close();
        }

    }

    public static String getMetricsString() {
        if (registry == null)
            registry = MeterRegistry.registry;
        return registry.scrape();
    }
}