Let me set the scene: I’m working on a Python app — pretty standard stack, nothing wild. Then out of nowhere...
Segmentation fault.
Wait. What? In Python?
Yeah. That was my reaction too.
Isn't Python safe from stuff like this?
Usually, yes. One of the reasons I love Python is because it protects you from low-level memory issues. But here's the catch: if you're using C extensions, or database drivers with native bindings under the hood... the safety net can have holes.
And that’s exactly what happened to me.
What Went Wrong
In my app, I was using mysql-connector-python to talk to a MySQL database. Everything looked fine on the surface.
But over time, the app would randomly crash with a segfault. No Python stack trace, just a hard exit.
I was stumped.
Enter: faulthandler + gdb
To investigate, I enabled Python’s built-in faulthandler module to try and catch something useful. I also ran the app with gdb to get a trace of what was going on at the C level.
And eventually, I found it.
The culprit?
Too many open MySQL connections. 😅
Turns out I was opening a new connection to the database on every single request — but I wasn’t closing them properly. No pooling, no reuse.
Eventually MySQL hit its connection limit and just bailed — crashing everything along with it.
The Fix: Connection Pooling FTW
The solution was (thankfully) pretty straightforward: I implemented a connection pool using mysql.connector.pooling.
Now the connections are managed properly, reused across requests, and I don’t run out of resources.
No segfaults. No database freakouts. No angry sysadmins. 🎉
Takeaways
Yes, Python can segfault. Especially when you're using C extensions or native libraries.
Always manage your database connections carefully.
Use tools like faulthandler and gdb to dig into the deeper layers when the usual logs don't help.
Don’t assume you're immune to low-level bugs just because you're writing high-level code.
TL;DR
If you're seeing weird crashes in Python, especially when working with databases or C extensions — don’t rule out things like memory errors or connection overloads.
Take the time to investigate. Your future self (and your uptime dashboard) will thank you. 🙌
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