HealthCheck called every 3seconds after dev-ui opened

[T-Celor]

Describe the bug

In my Quarkus application, I have a Wellness class implementing HealthCheck with a log inside. If I do a call on /q/health/well, I have my log in the console. But if I open the Dev-UI, HealthCheck is called every 3 seconds unless I close the Dev-UI, and I cannot disable this behavior.

Expected behavior

When I open the dev-ui, the HealthCheck should not be called every 3 seconds, like in the previous version quarkus (3.23.X). Or at least, if i close the Dev-UI I should return in the same behavior than before opening the Dev-UI.

Actual behavior

When I open the Dev-UI, the HealthCheck is called every 3 seconds. If I close the Dev-UI the behavior persist.

Console :
2025-07-04 10:39:36,215 INFO [io.quarkus] (Quarkus Main Thread) XXX 1.0.0-SNAPSHOT on JVM (powered by Quarkus 3.24.1) started in 3.030s. Listening on: http://localhost:9000

2025-07-04 10:39:36,218 INFO [io.quarkus] (Quarkus Main Thread) Profile dev activated. Live Coding activated.
2025-07-04 10:39:36,218 INFO [io.quarkus] (Quarkus Main Thread) Installed features: [cdi, smallrye-context-propagation, smallrye-health, vertx]
------ OPEN DEV-UI ------
2025-07-04 10:40:21,883 INFO [org.acm.hea.CustomHealthCheck] (vert.x-worker-thread-1) Called CustomHealthCheck
2025-07-04 10:40:21,883 INFO [org.acm.hea.CustomHealthCheck] (vert.x-worker-thread-2) Called CustomHealthCheck
2025-07-04 10:40:24,883 INFO [org.acm.hea.CustomHealthCheck] (vert.x-worker-thread-1) Called CustomHealthCheck
2025-07-04 10:40:27,878 INFO [org.acm.hea.CustomHealthCheck] (vert.x-worker-thread-1) Called CustomHealthCheck
2025-07-04 10:40:30,884 INFO [org.acm.hea.CustomHealthCheck] (vert.x-worker-thread-1) Called CustomHealthCheck
2025-07-04 10:40:33,877 INFO [org.acm.hea.CustomHealthCheck] (vert.x-worker-thread-1) Called CustomHealthCheck
2025-07-04 10:40:36,872 INFO [org.acm.hea.CustomHealthCheck] (vert.x-worker-thread-1) Called CustomHealthCheck
2025-07-04 10:40:39,875 INFO [org.acm.hea.CustomHealthCheck] (vert.x-worker-thread-1) Called CustomHealthCheck

How to Reproduce?

        <dependency>
            <groupId>io.quarkus</groupId>
            <artifactId>quarkus-smallrye-health</artifactId>
        </dependency>

import io.quarkus.logging.Log;
import jakarta.enterprise.context.ApplicationScoped;

import org.eclipse.microprofile.health.HealthCheck;
import org.eclipse.microprofile.health.HealthCheckResponse;

import io.smallrye.health.api.Wellness;

@Wellness
@ApplicationScoped
public class CustomHealthCheck implements HealthCheck {

    @Override
    public HealthCheckResponse call() {
        Log.infov("Called CustomHealthCheck");
        return HealthCheckResponse
                .named("CustomHealthCheck")
                .build();
    }
}

Launch the application with mvn quarkus:dev, open the Dev-UI, observe log generated every 3 seconds, close the Dev-UI, observe log generated every 3 seconds.

Output of uname -a or ver

No response

Output of java -version

21.0.7

Quarkus version or git rev

3.24.1

Build tool (ie. output of mvnw --version or gradlew --version)

3.8.7

Additional information

No response

[quarkus-bot]

/cc @cescoffier (devui), @jmartisk (health), @phillip-kruger (devui), @xstefank (health)

[Chu3laMan]

I would like to assign this one to me, I am gonna start work on it

[phillip-kruger]

Just to understand , why is this an issue ? When deploying into a cloud environment, health checking will also be called frequently.

[T-Celor]

Hi @phillip-kruger, the issue here is that the dev-ui is not idempotent. When you open it, it changes the behavior of the application, even after closing it. Is it intentional that opening the dev-ui triggers a health check every 3 seconds, and this behavior persists after the dev-ui is closed?

[phillip-kruger]

Why do you say it's not idempotent ? And even so why should it be idempotent ? So it's the health card in Dev UI that check the health to report it on the screen. So opening the dev ui will make this happen yes. When it's closed it should stop. If that is not the case we should look at that. We can also add a "turn off" button I guess, I just don't understand (still) why this is a problem. Health check exist to be able to check the health.

[Chu3laMan]

Hi @phillip-kruger as the reporter of the issue revealed above, once the dev ui closed, it should not send the heartbeat check, he said,

the current behavior was not in the previous Quarkus version, as he aforementione.

[phillip-kruger]

the current behavior was not in the previous Quarkus version, as he aforementione.

Is that why you say it's not idempotent ? Or is that another issue ? Sorry just trying to get to the issue here.

So yes it should definitely stop once the dev-ui is closed - I can look into that.

[Chu3laMan]

the current behavior was not in the previous Quarkus version, as he aforementione.

Is that why you say it's not idempotent ? Or is that another issue ? Sorry just trying to get to the issue here.

So yes it should definitely stop once the dev-ui is closed - I can look into that.

I am just trying to help here, I am not the one who reveals idempotent concept,

Yes, that's it, it should be stop sending heartbeat once the dev ui is closed.

[phillip-kruger]

I am just trying to help here

Me too :)

[vsevel]

one can argue whether or not a 3 seconds period is too small. the "good" value is very subjective, but a refresh every 10 seconds at least would be ok I suppose. we were surprised how much our healthchecks were hit. it is ok if we are just talking about internal processing, but many checks will attempt external connections, which may timeout.

[T-Celor]

I think we can forget the "idempotent concept" it was just to resume that the action of opening the dev-ui provoke health check for every 3s even after closing the dev-ui.

As mentioned in the original post, the problem is the persistence of the 3s health check (provoked by the dev-ui openning) after closing the dev-ui.