Memory constantly increasing

[kyal2000]

I'm compiling following simple example:

import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;

@Path("hello")
public class GreetingResource {

    @GET
    @Produces(MediaType.TEXT_PLAIN)
    public String hello() {
        return "Hello";
    }
}

And deploy the native image on my GCP Kubernetes Cluster.
The memory starts at ~5MB but over time it raises and never drop back down.

I get the same behavior using a Apache Camel Route which starts up every second and does nothing:

import org.apache.camel.builder.RouteBuilder;

public class Demo extends RouteBuilder {
  @Override
  public void configure() throws Exception {
      from("timer:camel-demo?period=1000")
        .setBody()
          .constant("");
  }
}

It looks like this:

I'm compiling it with:

mvn clean package -DskipTests -Dquarkus.container-image.push=true -Pnative

It looks like there exists already a very similar issue: #2428

[oubidar-Abderrahim]

Could you please share the code source of this example? (dependencies included)

[kyal2000]

You can find both examples in this repo: https://github.com/kyal2000/quarkus

[kyal2000]

We tested a few things...
There is no difference if we compile it on Linux or on Windows
There is no difference if we deploy it on GCP or AWS (as expected)

If we set a HeapSize limit the memory usage stays constant but the higher the limit the higher the memory consumption

[SergejIsbrecht]

@kyal2000, which GC are you using? Most likely the GC does not uncommit requested memory after a GC cycle.

[kyal2000]

I don't set a specific GC so it should be the default GC, which should be the Serial GC.

https://www.graalvm.org/reference-manual/native-image/MemoryManagement/

[kyal2000]

@oubidar-Abderrahim do you have an idea where this comes from?

[oubidar-Abderrahim]

Hi, I have a few questions:

1. Which version of GraalVM you're using?
2. Can you confirm the issue is still reproducing in the latest snapshot build of 21.2.0?
3. Does running the application locally on Docker show an increase in memory or only if it is deployed to GCP or AWS?

[kyal2000]

1. I'm using Version 21.1.0 with Java 11
2. Yes the behaviour remains the same with v. 21.2.0
3. Locally on docker i get following interesting behaviour:
   
   So it went from 6,5MB to ~40MB, then dropped to ~10MB and since then it's constantly increasing again and now requires over 60MB.

[oubidar-Abderrahim]

Thank you for reporting this, this is now tracked internally on GR-32069

[christianwimmer]

That sounds like that the young generation is just slowly filling up (because of background threads that allocate slowly but steadily). Since the default young generation size is 256 MByte, that amount of memory is allocated before the first GC happens. Sounds like you can experiment with -Xmn to size the young generation, and -XX:+PrintGC to see what GC is going on.