As of a couple of days ago, a new line is showing up in my logs when I reboot my Community Cloud-hosted app: Uvicorn server started on 0.0.0.0:8501. This alone isn’t an issue, although I’m curious about what’s causing it, since I haven’t changed my requirements file (which is also pretty simple: just streamlit and pandas). However, when I went to check the logs this morning, I discovered that the app also apparently did a full reboot and rebuild overnight, even though I hadn’t changed anything in GitHub since the previous reboot. This means that I lost any possible error messages in the logs (although hopefully there weren’t any), and I’m completely mystified as to what might have caused it. (An attempted Google search gives me an AI result that talks about excessively long scripts and memory leaks, but I’m pretty sure those aren’t relevant issues in my case.) GitHub site here. Thanks in advance for any help!
Hey there, thanks for your thoughtful question and for sharing your experience! 
The appearance of the “Uvicorn server started on 0.0.0.0:8501” log line is due to recent infrastructure changes on Streamlit Community Cloud—Streamlit now uses Uvicorn as part of its backend server stack, so this is expected and not an error. You don’t need to update your requirements for this; it’s handled by the platform itself.
As for the unexpected overnight reboot and rebuild: Streamlit Community Cloud apps can be automatically restarted for several reasons, including infrastructure upgrades, resource balancing, or platform maintenance—even if you haven’t pushed new code. This is normal behavior and not something you can control from your app or repo. Unfortunately, this does mean logs from before the reboot are lost, as each rebuild clears the previous session’s logs. For more on this, see the official docs on app management and resource limits and resource limits.
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