ConnectionManagerLeaseDemo.java

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 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
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package org.apache.hc.client5.http.observation.example;

import java.util.EnumSet;

import io.micrometer.core.instrument.Metrics;
import io.micrometer.core.instrument.search.Search;
import io.micrometer.observation.ObservationRegistry;
import io.micrometer.prometheusmetrics.PrometheusConfig;
import io.micrometer.prometheusmetrics.PrometheusMeterRegistry;
import org.apache.hc.client5.http.impl.classic.CloseableHttpClient;
import org.apache.hc.client5.http.impl.classic.HttpClientBuilder;
import org.apache.hc.client5.http.impl.classic.HttpClients;
import org.apache.hc.client5.http.impl.io.PoolingHttpClientConnectionManagerBuilder;
import org.apache.hc.client5.http.io.HttpClientConnectionManager;
import org.apache.hc.client5.http.observation.HttpClientObservationSupport;
import org.apache.hc.client5.http.observation.MetricConfig;
import org.apache.hc.client5.http.observation.ObservingOptions;
import org.apache.hc.client5.http.observation.impl.MeteredConnectionManager;
import org.apache.hc.core5.http.ClassicHttpResponse;
import org.apache.hc.core5.http.HttpHost;
import org.apache.hc.core5.http.io.support.ClassicRequestBuilder;

public final class ConnectionManagerLeaseDemo {

    public static void main(final String[] args) throws Exception {
        final PrometheusMeterRegistry reg = new PrometheusMeterRegistry(PrometheusConfig.DEFAULT);
        Metrics.addRegistry(reg);

        final ObservationRegistry obs = ObservationRegistry.create();
        final MetricConfig mc = MetricConfig.builder().prefix("demo").build();
        final ObservingOptions opts = ObservingOptions.builder()
                .metrics(EnumSet.of(ObservingOptions.MetricSet.BASIC, ObservingOptions.MetricSet.CONN_POOL))
                .build();

        final HttpClientConnectionManager rawCm = PoolingHttpClientConnectionManagerBuilder.create().build();
        final HttpClientConnectionManager cm = new MeteredConnectionManager(rawCm, reg, mc, opts);

        final HttpClientBuilder builder = HttpClients.custom().setConnectionManager(cm);
        HttpClientObservationSupport.enable(builder, obs, reg, opts, mc);

        try (final CloseableHttpClient client = builder.build()) {
            final HttpHost target = new HttpHost("http", "httpbin.org", 80);
            final ClassicHttpResponse rsp = client.executeOpen(
                    target,
                    ClassicRequestBuilder.get("/get").build(),
                    null);
            System.out.println("status=" + rsp.getCode());
            rsp.close();
        }

        System.out.println("pool.lease  present? " + (Search.in(reg).name("demo.pool.lease").timer() != null));
        System.out.println("pool.leases present? " + (Search.in(reg).name("demo.pool.leases").counter() != null));
        System.out.println("--- scrape ---");
        System.out.println(reg.scrape());
    }

    private ConnectionManagerLeaseDemo() {
    }
}