👀 Views: 1682 💬 Answers: 1 📅 Created: 2025-06-03

postgresql asyncio deadlock Python

I've been working on this all day and Quick question that's been bugging me - I'm working on a Python application using `asyncpg` to interact with a PostgreSQL database on Ubuntu 22.04. Recently, I've come across a deadlock scenario that occurs intermittently when multiple coroutines attempt to insert data into the same table simultaneously. The deadlock happens despite my use of transactions, and I'm not sure how to resolve it. My database version is PostgreSQL 14.1. Here's the relevant part of my code where the inserts are being made: ```python import asyncio import asyncpg async def insert_data(conn, data): async with conn.transaction(): await conn.execute('INSERT INTO my_table (column1, column2) VALUES ($1, $2)', data[0], data[1]) async def main(): conn = await asyncpg.connect(user='user', password='password', database='db', host='127.0.0.1') await asyncio.gather( insert_data(conn, (1, 'foo')), insert_data(conn, (2, 'bar')), insert_data(conn, (3, 'baz')) ) await conn.close() if __name__ == '__main__': asyncio.run(main()) ``` When I run this script, I sometimes receive the following behavior: ``` behavior: deadlock detected DETAIL: Process 12345 waits for ShareLock on transaction 67890; blocked by process 54321. ``` I've tried adding more logging around the inserts to understand the timing better, but it doesn’t seem to provide insight into why the deadlocks are occurring. Additionally, I made sure the table structure is optimized for concurrent inserts and the database settings related to locking seem appropriate. I would appreciate any suggestions on how to avoid these deadlocks or if there are any specific patterns in `asyncpg` that I should follow to handle concurrent transactions more effectively. Could it also be a configuration scenario on PostgreSQL itself? I'm open to any suggestions. Any feedback is welcome!