Checklist

• I have verified that the issue exists against the master branch of Celery.
• This has already been asked to the discussions forum first.
• I have read the relevant section in the
  contribution guide
  on reporting bugs.
• I have checked the issues list
  for similar or identical bug reports.
• I have checked the pull requests list
  for existing proposed fixes.
• I have checked the commit log
  to find out if the bug was already fixed in the master branch.
• I have included all related issues and possible duplicate issues
  in this issue (If there are none, check this box anyway).

Mandatory Debugging Information

• I have included the output of celery -A proj report in the issue.
  (if you are not able to do this, then at least specify the Celery
  version affected).
• I have verified that the issue exists against the master branch of Celery.
• I have included the contents of pip freeze in the issue.
• I have included all the versions of all the external dependencies required
  to reproduce this bug.

Optional Debugging Information

• I have tried reproducing the issue on more than one Python version
  and/or implementation.
• I have tried reproducing the issue on more than one message broker and/or
  result backend.
• I have tried reproducing the issue on more than one version of the message
  broker and/or result backend.
• I have tried reproducing the issue on more than one operating system.
• I have tried reproducing the issue on more than one workers pool.
• I have tried reproducing the issue with autoscaling, retries,
  ETA/Countdown & rate limits disabled.
• I have tried reproducing the issue after downgrading
  and/or upgrading Celery and its dependencies.

Related Issues and Possible Duplicates

Related Issues

• None

Possible Duplicates

• None

Environment & Settings

Celery version: 5.0.0

[2021-11-03 08:16:01,856: ERROR/ForkPoolWorker-2] Error in:
1: INSERT { task: {"status": "PROGRESS", "result": {"progress": 1}, "traceback": null, "children": [], "date_done": null, "task_id": "a5320fd7-b2ed-4c03-bbb8-55d7a6ac4394"}, _key: "celery-task-meta-a5320fd7-b2ed-4c03-bbb8-5
5d7a6ac4394" } INTO celery.
->AQL: unique constraint violated - in index primary of type primary over '_key'; conflicting key: celery-task-meta-a5320fd7-b2ed-4c03-bbb8-55d7a6ac4394 (while executing). Errors: {'code': 409, 'error': True, 'errorMessage': "AQL: unique constraint violated - in in
dex primary of type primary over '_key'; conflicting key: celery-task-meta-a5320fd7-b2ed-4c03-bbb8-55d7a6ac4394 (while executing)", 'errorNum': 1210}

Steps to Reproduce

Required Dependencies

• Minimal Python Version: 3.8
• Minimal Celery Version: 5.0.0
• Minimal Kombu Version: 5.0.2
• Minimal Broker Version: N/A or Unknown
• Minimal Result Backend Version: N/A or Unknown
• Minimal OS and/or Kernel Version: N/A or Unknown
• Minimal Broker Client Version: N/A or Unknown
• Minimal Result Backend Client Version: N/A or Unknown

Python Packages

Other Dependencies

Minimally Reproducible Test Case

from celery import Celery
import time
celery_app = Celery('tasks', broker='...',  backend='ARANGODB...')
@celery_app.task(name="my_task")
def my_task():
	for i in range(10);
		my_task.update_state(state="PROGRESS", meta={'progress': i})
		time.sleep(2)

result = my_task.apply_async()
while not result.successful():
	print(result.state)
	time.sleep(2)

Expected Behavior

I create a task with update_state using ArangoDB backend. I think it should update the current state in the same document of ArangoDB and I should be able to retrieve the most recent update from the database.

Actual Behavior

I cannot receive the updated state and find this error for every update_state perform when update_state to ArangoDB backend.
It seems that the the first state update already take the _key and ArangoDB does not allow to write data with the same key. If the code use 'overwrite', it should solve the issue.

This is one of the error message I got.

[2021-11-03 08:16:01,856: ERROR/ForkPoolWorker-2] Error in:
1: INSERT { task: {"status": "PROGRESS", "result": {"progress": 1}, "traceback": null, "children": [], "date_done": null, "task_id": "a5320fd7-b2ed-4c03-bbb8-55d7a6ac4394"}, _key: "celery-task-meta-a5320fd7-b2ed-4c03-bbb8-5
5d7a6ac4394" } INTO celery.
->AQL: unique constraint violated - in index primary of type primary over '_key'; conflicting key: celery-task-meta-a5320fd7-b2ed-4c03-bbb8-55d7a6ac4394 (while executing). Errors: {'code': 409, 'error': True, 'errorMessage': "AQL: unique constraint violated - in in
dex primary of type primary over '_key'; conflicting key: celery-task-meta-a5320fd7-b2ed-4c03-bbb8-55d7a6ac4394 (while executing)", 'errorNum': 1210}