Fix H18 timeout by keeping event loop running after startup #408
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Summary of Changes
Hello @pt2302, I'm Gemini Code Assist1! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!
This pull request resolves a critical deployment issue on Heroku, specifically H18 timeout errors, by ensuring the application's asynchronous event loop remains active after its initial startup. The changes prevent the premature termination of the event loop, which was causing the Server Request Interrupted errors.
Highlights
- Event Loop Management: Modified the application's main entry point to explicitly keep the asyncio event loop running indefinitely after startup.
- Heroku H18 Timeout Fix: Addressed the Server Request Interrupted (H18) errors encountered on Heroku by preventing the event loop from terminating prematurely.
- Asynchronous Execution: Transitioned the main function to an async function and updated the application's execution to use asyncio.run().
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Pull Request Overview
This PR fixes an H18 timeout issue on Heroku by preventing the event loop from terminating after bot startup. The change ensures the application continues running indefinitely to handle incoming requests.
- Replaced tornado's
run_syncwith native asyncio for event loop management - Added an infinite wait after startup to keep the event loop alive
- Removed tornado import as it's no longer needed
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| """main function for bot command""" | ||
| tornado.ioloop.IOLoop.current().run_sync(async_main) | ||
| await async_main() | ||
| await asyncio.Event().wait() |
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Using asyncio.Event().wait() without ever setting the event creates an infinite wait that can only be interrupted by process termination. Consider using a more explicit approach like while True: await asyncio.sleep(3600) or creating a named event that can be set for graceful shutdown.
| await asyncio.Event().wait() | |
| while True: | |
| await asyncio.sleep(3600) |
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Code Review
This pull request correctly addresses the H18 timeout issue on Heroku by ensuring the asyncio event loop remains active after the application starts. The change from a synchronous main function using tornado.ioloop to an asynchronous one using asyncio.Event().wait() is a clean and effective solution. The removal of the unused tornado import is also a good cleanup. The implementation is solid and I have no further suggestions.
What are the relevant tickets?
Follow-up to #407.
Description (What does it do?)
This PR fixes an issue with a
Server Request Interruptederror when deployed to Heroku, caused by the event loop terminating after Doof startup.How can this be tested?
Test by deploying to Heroku and making sure there are no H18 errors.