[Core] `ray.get_runtime_context().namespace` returns incorrect namespace in Actor Tasks

[woshiyyya]

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What happened + What you expected to happen

ray.get_runtime_context().namespace always returns the default namespace, even if the Actor is launched in a custom namespace.

Versions / Dependencies

nightly

Reproduction script

import ray

@ray.remote
class Actor:
    def show_namespace(self):
        print("namespace: ", ray.get_runtime_context().namespace)

# Create an actor with specified namespace.
actor = Actor.options(
    name="my_actor", 
    namespace="actor_namespace", # <- specify namespace here
    lifetime="detached"
).remote()

ray.get(actor.show_namespace.remote())

# The Output
# >>> (Actor pid=30522) namespace:  540bbea1-bc1c-4ec3-8447-a858958151ce

It should be "actor_namespace" instead.

Issue Severity

High: It blocks me from completing my task.

[982945902]

maybe it is not a bug in local mode

look at this code in ray/src/ray/core_worker/core_worker.cc

[982945902]

@jjyao @kevin85421 https://github.com/ray-project/ray/pull/45025 i add a api to support this issue

[hongchaodeng]

ray.get_runtime_context() returns the job config for entire Ray job, not specific task/actor.

Ray does provide an API to access specific actor via ray.get_actor(<name>, <namespace>). But you have to specify namespace with that.

For this issue, it is using the API for the wrong job IMHO.

May I ask what's your use case to get the namespace inside the actor? Because in your code you can easily pass down the namespace to the actor.

[kevin85421]

ray.get_runtime_context() returns the job config for entire Ray job, not specific task/actor.

Hmm. The RuntimeContext's constructor is initialized with a worker process. I believe that RuntimeContext is specific to each worker process (task/actor). I also performed a simple experiment. Do I miss anything?

import ray

ray.init()

@ray.remote
def f():
    runtime_context = ray.get_runtime_context()
    print("Ray task")
    print("Job", ray.get_runtime_context().get_job_id())
    print("Task", ray.get_runtime_context().get_task_id())
    print("Actor", ray.get_runtime_context().get_actor_id())

@ray.remote
class actor:
    def __init__(self):
        pass
    def print_message(self):
        runtime_context = ray.get_runtime_context()
        print("Ray actor")
        print("Job", ray.get_runtime_context().get_job_id())
        print("Task", ray.get_runtime_context().get_task_id())
        print("Actor", ray.get_runtime_context().get_actor_id())

task_obj_ref = f.remote()
ray.get(task_obj_ref)

actor_instance = actor.remote()
ray.get(actor_instance.print_message.remote())

[woshiyyya]

Thanks for following up. As @kevin85421 said here, an api that returns the actor's namespace suffice my use case.