topic Re: Databricks Apps Crashes Unexpectedly Without Showing any Logs in Community Articles

Databricks Apps Crashes Unexpectedly Without Showing any Logs

sahil_101 — Mon, 08 Sep 2025 14:49:17 GMT

Hi All,

I coded up a Databricks app using fastapi which seems to be crashing on deployment. Databricks throws the error that "app crashed at startup" but the logging page is empty. So I do not know what went wrong. Any ideas on how to debug the problem?

Re: Databricks Apps Crashes Unexpectedly Without Showing any Logs

Khaja_Zaffer — Mon, 08 Sep 2025 16:14:23 GMT

Hello @sahil_101

Good day!!

Are you trying to call something? can you share more details on this?

Re: Databricks Apps Crashes Unexpectedly Without Showing any Logs

szymon_dybczak — Mon, 08 Sep 2025 17:31:33 GMT

Hi @sahil_101 ,

If logs are not available at UI you can try another method. Append /logs to your app URL.
For example, if your app URL is https://my-app-1234567890.my-instance.databricksapps.com, logs are available at https://my-app-1234567890.my-instance.databricksapps.com/logz

Also if possible could you share code of your app (without private information etc.)?

Re: Databricks Apps Crashes Unexpectedly Without Showing any Logs

sahil_101 — Tue, 09 Sep 2025 20:36:23 GMT

I want to update that I have been able to solve the problem and get the app running. The problem was related to trying to import from anoter folder instead of downloading the package using its wheel file. Just for the record, had already tried the logz method but that still gave a blank page.

However, I still have the problem of the logs not showing up. Maybe it has something to do with using uvicorn to run the app?

Consequently, I have no way of debugging code on my app, so if my api request returns an "internal server error", I do not know where my program failed.

So as a follow up question, anyone knows how to setup logging for a fastapi application run using uvicorn on Databricks?