Python Timeouts

An unresponsive service can be worse than a down one. It can tie up your entire system if not handled properly. All network requests should have a timeout.

Here’s how to add timeouts for popular Python packages. All have been tested. The default is no timeout, unless otherwise specified. Enjoy!

Packages

Standard library

• http
• smtplib
• socket
• subprocess

PyPI

• aiohttp
• asyncpg
• boto3
• elasticsearch
• mongoengine
• mysqlclient
• opensearch-py
• psycopg
• psycopg2
• pymemcache
• pymongo
• redis
• requests
• SQLAlchemy

Standard Library

http

HTTPConnection(host, port, timeout=1)

Raises socket.timeout

smtplib

SMTP(host, timeout=1)

Raises

• socket.timeout on connect timeout
• smtplib.SMTPServerDisconnected on read timeout

socket

sock.settimeout(1)

Raises socket.timeout

subprocess

subprocess.run(cmd, timeout=1)

Raises subprocess.TimeoutExpired

PyPI

aiohttp

timeout = aiohttp.ClientTimeout(total=1)
async with aiohttp.ClientSession(timeout=timeout) as session:
    # ...

Raises asyncio.exceptions.TimeoutError

asyncpg

asyncpg.connect(timeout=1)

Default: 60s

Raises asyncio.exceptions.TimeoutError

boto3

boto3.client('s3', config=Config(connect_timeout=1, read_timeout=1))

Raises

• botocore.exceptions.ConnectTimeoutError on connect timeout
• botocore.exceptions.ReadTimeoutError on read timeout

elasticsearch

Elasticsearch(timeout=1)

Raises elasticsearch.exceptions.ConnectionError

mongoengine

connect(connectTimeoutMS=1000, socketTimeoutMS=1000, serverSelectionTimeoutMS=1000)

Raises pymongo.errors.ServerSelectionTimeoutError

mysqlclient

MySQLdb.connect(connect_timeout=1)

Raises MySQLdb._exceptions.OperationalError

opensearch-py

OpenSearch(timeout=1)

Raises opensearchpy.exceptions.ConnectionError

psycopg

psycopg.connect(connect_timeout=1)

Raises psycopg.OperationalError

psycopg2

psycopg2.connect(connect_timeout=1)

Raises psycopg2.OperationalError

pymemcache

Client(host, connect_timeout=1, timeout=1)

Raises socket.timeout

pymongo

MongoClient(connectTimeoutMS=1000, socketTimeoutMS=1000, serverSelectionTimeoutMS=1000)

Default: 20s connect timeout, 30s server selection timeout

Raises pymongo.errors.ServerSelectionTimeoutError

redis

Redis(socket_connect_timeout=1, socket_timeout=1)

Raises redis.exceptions.TimeoutError

requests

requests.get(url, timeout=1)

Raises

• requests.exceptions.ConnectTimeout on connect timeout
• requests.exceptions.ReadTimeout on read timeout

SQLAlchemy

create_engine(url, connect_args={'connect_timeout': 1})

Raises sqlalchemy.exc.OperationalError

Don’t see a library you use?

Let us know. Even better, create a pull request for it.

Running the Tests

git clone https://github.com/ankane/python-timeouts.git
cd python-timeouts
pip install -r requirements.txt

To run all tests, use:

pytest

To run individual tests, use:

pytest tests/test_redis.py