MongoDB result backend does not work with mongodb+srv:// URL

Author: DlubakCreated May 6, 2022Updated Sep 12, 2026

LabelsIssue Type: Bug ReportComponent: MongoDB Results Backend

Checklist https://github.com/celery/celery/blob/master/celery/backends/mongodb.py#L136-L163

Steps to reproduce Set the MongoDB URL to one like:

celery_config.py

class CeleryConfig:
    broker_url = broker_url
    result_backend = "mongodb+srv://admin:[email protected]/"
    accept_content = ["json"]
    result_serializer = "json"
    task_serializer = "json"
    mongodb_backend_settings = {
        "database": "steps",
        "taskmeta_collection": "step",
    }

pyproject.toml

[tool.poetry.dependencies]
python = "^3.9"
boto3 = "^1.21.17"
celery = "^5.2.3"
mongoengine = "^0.24.1"

celery_worker.py

# Initialization of Celery APP
app = Celery(backend=CELERY_BACKEND_URL)
app.config_from_object(CeleryConfig)

Expected behavior This works.

Actual behavior: celery worker log also states that url is changed from -> "mongodb+srv://admin:[email protected]/" to this -> mongodb://admin:[email protected]/ and it also adds default port to url and srv version of mongo cannot have port number in it.

-> which causes this exception to raise

ServerDescription ('testing.company.mongodb.net', 27017) server_type: Unknown, rtt: None, error=AutoReconnect('testing.company.mongodb.net:27017: [Errno -2] Name or service not known')>]>```

Source: celery/celery

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