Vertx - InfluxDB metrics keeping connection open

Question

I am trying to incorporate metrics reporting into my Vertx application, through an InfluxDB instance. However, when I try to gracefully end my application, there is a hanging thread somewhere. I managed to track it down to the InfluxDB connection for vertx's metrics reporting, or so it seems, but I don't see a way to kill it off. Can anyone point me in the right direction?

A minimal working example (if you disable the metrics, the application gracefully finishes, otherwise, it hangs):

import io.vertx.core.Vertx;
import io.vertx.core.VertxOptions;
import io.vertx.micrometer.MicrometerMetricsOptions;
import io.vertx.micrometer.VertxInfluxDbOptions;
import io.vertx.micrometer.backends.BackendRegistries;

public class MWE {
    public static void main(String[] args) {
        //setting up the metric options for influxdb. seems to work in MWE without credentials
        MicrometerMetricsOptions metricsOptions = new MicrometerMetricsOptions()
                .setRegistryName("data-client")
                .setInfluxDbOptions(new VertxInfluxDbOptions()
                        //disabling this would make sure the application _does_ gracefully exit
                        .setEnabled(true)
                )
                .setEnabled(true);

        //setting up the vertx instance
        Vertx vertx = Vertx.vertx(
                new VertxOptions()
                        .setMetricsOptions(metricsOptions)
                        .setWorkerPoolSize(50)
        );

        //stop vertx after a second
        vertx.setTimer(1000, timerID -> {
            //closing the vertx instance
            vertx.close(result -> System.out.println("Vertx was closed."));
            //closing the registry of metrics to influxdb
            BackendRegistries.getNow("data-client").close();
            System.out.println("Closed everything");
        });

        System.out.println("Done with main");
    }
}

Answer 1

As mentioned in the GitHub issue tracker (https://github.com/vert-x3/vertx-micrometer-metrics/issues/36), this was an issue in version 1.0.0 of micrometrics. Bumping the version to 1.0.5 temporarily fixes the bug, awaiting the update of the dependency on micrometer by vertx-micrometer-metrics.