[core][java][Bug] Cannot put object references onto object store with modern version of Java

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Ray Component

Ray Core

Issue Severity

High: It blocks me to complete my task.

What happened + What you expected to happen

With Java 17, Java code that attempts to write an object reference to object storage fails. More specifically:

• The code from the test case https://github.com/ray-project/ray/blob/master/java/test/src/main/java/io/ray/test/ObjectRefTransferTest.java does not work on Java 17
• The following simpler test program also does not work:

  Ray.init();
  List<ObjectRef<String>> refsList = new ArrayList<ObjectRef<String>>();
  Ray.put(refsList);
  

In both cases, an exception similar to the following is thrown:

java.lang.RuntimeException: java.lang.reflect.InaccessibleObjectException: Unable to make field private final byte[] java.lang.String.value accessible: module java.base does not "opens java.lang" to unnamed module @6193b845

	at io.ray.runtime.serializer.MessagePackSerializer.encode(MessagePackSerializer.java:276)
	at io.ray.runtime.serializer.Serializer.encode(Serializer.java:8)
	at io.ray.runtime.object.ObjectSerializer.serialize(ObjectSerializer.java:165)
	at io.ray.runtime.object.ObjectStore.put(ObjectStore.java:64)
	at io.ray.runtime.AbstractRayRuntime.put(AbstractRayRuntime.java:78)
	at io.ray.api.Ray.put(Ray.java:62)

This problem appears to be due to some changes to Java’s security model that were introduced in Java 9. See this post on StackOverflow for more information.

This issue is blocking me because the code I want to run does not work with Java 8.

Versions / Dependencies

Ray 1.10 MacOS 12.2.1 (Monterey) Java version info:

openjdk 17.0.2 2022-01-18
OpenJDK Runtime Environment Temurin-17.0.2+8 (build 17.0.2+8)
OpenJDK 64-Bit Server VM Temurin-17.0.2+8 (build 17.0.2+8, mixed mode, sharing)

Reproduction script

Ray.init();
List<ObjectRef<String>> refsList = new ArrayList<ObjectRef<String>>();
Ray.put(refsList);

Anything else

No response

Are you willing to submit a PR?

• Yes I am willing to submit a PR!

[kfstorm]

Ray Java depends on https://github.com/RuedigerMoeller/fast-serialization for serialization, and it doesn’t support Java 17 yet. See https://github.com/RuedigerMoeller/fast-serialization/issues/312 for details. @jovany-wang Could we try adding this to our codebase?

[stale[bot]]

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