TimeoutError with multi-agent

[abpaudel]

I'm trying to get top-down view with two agents in the scene using the following code.

import random
import matplotlib.pyplot as plt
import prior
from ai2thor.controller import Controller
from ai2thor.platform import CloudRendering


NUM_AGENTS = 1

dataset = prior.load_dataset("procthor-10k")
scene = dataset["train"][0]

controller = Controller(platform=CloudRendering, scene=scene)

multi_agent_event = controller.step(dict(action='Initialize', agentCount=NUM_AGENTS))
event = controller.step(action="GetMapViewCameraProperties")
event = controller.step(action="AddThirdPartyCamera", **event.metadata["actionReturn"])

reachable_positions_ = controller.step(action="GetReachablePositions").metadata["actionReturn"]
reachable_positions = [(p["x"], p["y"], p["z"]) for p in reachable_positions_]

random.seed(42)
for i in range(NUM_AGENTS):
    pos = random.choice(reachable_positions_)
    controller.step(dict(action="Teleport", position=pos, agentId=i))

img = controller.last_event.events[0].third_party_camera_frames[-1][::-1, ...]
plt.imshow(img)
plt.show()

This code works as expected. However, I get the following TimeoutError for NUM_AGENTS = 2. Let me know how I can get this to work for 2 or more agents.

Traceback (most recent call last):
  File "/opt/venv/lib/python3.10/site-packages/ai2thor/controller.py", line 979, in step
    self.last_event = self.server.receive()
  File "/opt/venv/lib/python3.10/site-packages/ai2thor/fifo_server.py", line 229, in receive
    metadata, files = self._recv_message(
  File "/opt/venv/lib/python3.10/site-packages/ai2thor/fifo_server.py", line 145, in _recv_message
    header = self._read_with_timeout(
  File "/opt/venv/lib/python3.10/site-packages/ai2thor/fifo_server.py", line 134, in _read_with_timeout
    raise TimeoutError(f"Reading from AI2-THOR backend timed out (using {timeout}s) timeout.")
TimeoutError: Reading from AI2-THOR backend timed out (using 100.0s) timeout.

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/ab/projects/ai2thor/multiagent_demo.py", line 25, in <module>
    controller.step(dict(action="Teleport", position=pos, agentId=i))
  File "/opt/venv/lib/python3.10/site-packages/ai2thor/controller.py", line 997, in step
    raise (TimeoutError if isinstance(e, TimeoutError) else RuntimeError)(
TimeoutError: Error encountered when running action {'action': 'Teleport', 'position': {'x': 2.75, 'y': 0.9009993672370911, 'z': 1.5}, 'agentId': 1, 'sequenceId': 9} in scene Procedural.

[NA-Wen]

I have the same problem. My code works as expected when initializing with 1 agent or 2 agents. However, I stuck in the initialize action and get TimeoutError for 3 agents.
The code:

controller = Controller(height=1000, width=1000)
controller.reset("FloorPlan" + str(floor_no)) 
print("Initializing agents: {}".format(3))
# Initialize n agents into the scene
multi_agent_event = controller.step(dict(action='Initialize', agentMode="default", snapGrid=False, gridSize=0.5, rotateStepDegrees=20, visibilityDistance=100, fieldOfView=90, agentCount=3))

The error:

Traceback (most recent call last):
  File "/workspace/ai2thor/logs/Wash_the_lettuce_and_place_lettuce_on_the_Countertop_plans_03-21-2025-08-37-59/executable_plan.py", line 69, in <module>
    multi_agent_event = c.step(dict(action='Initialize', agentMode="default", snapGrid=False, gridSize=0.5, rotateStepDegrees=20, visibilityDistance=100, fieldOfView=90, agentCount=3))
                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/workspace/venv/lib/python3.12/site-packages/ai2thor/controller.py", line 997, in step
    raise (TimeoutError if isinstance(e, TimeoutError) else RuntimeError)(
TimeoutError: Error encountered when running action {'action': 'Initialize', 'agentMode': 'default', 'snapGrid': False, 'gridSize': 0.5, 'rotateStepDegrees': 20, 'visibilityDistance': 100, 'fieldOfView': 90, 'agentCount': 3, 'sequenceId': 2} in scene FloorPlan6_physics.

[abpaudel]

@NA-Wen Your code works fine when I run on mine for 5 agents, so it may be a different issue than mine. As for my issue, it seems like multi-agent support doesn't yet exist for ProcTHOR scenes (see #1169). But since you are not using ProcTHOR scenes, yours should work fine for multi-agent.