Laravel App on Google App Engine Hangs with Responses Larger Than 450KB

I am facing a perplexing issue with my Laravel application hosted on Google App Engine (GAE)Standard ENV. While the application runs flawlessly in a local environment, I encounter a specific problem when hosted on GAE: API responses larger than approximately 450KB never complete; the requests hang and I receive no error and no logs are fired.

Context

• Local Environment: The application operates without issues. I can receive JSON responses of any size, including payloads of several MBs.
• Google App Engine Environment: Requests with responses larger than 450KB hang. There are no error logs in GAE indicating the problem.
• Type of Responses: The issue occurs with both JSON responses and rendering of HTML Blade pages.
• GAE Instance Size: I have tried scaling the instance resources up to the maximum, but the issue persists.
• Tests Conducted: I have performed tests with responses of various sizes to isolate the issue, but it seems to be specifically linked to responses over 450KB.

What I've Already Checked

1. App Engine Configuration: I haven't found any specific settings that could limit the size of the responses.
2. Payload Limits: I am aware that the payload limits on GAE are well above 450KB.
3. Timeouts and Resources: The response processing time never exceeds one second, so it seems not to be a timeout or insufficient resources issue.
4. Logging: There are no errors or warnings in the GAE logs that indicate the cause of the problem.

Specific Questions

1. Are there hidden settings or limitations in GAE that could be causing this behavior?
2. Could it be an issue related to handling large responses specific to the GAE Standard environment?
3. What other troubleshooting steps could I take to further isolate the cause?

Any suggestions or experiences with similar issues would be extremely helpful.

source https://stackoverflow.com/questions/77546339/laravel-app-on-google-app-engine-hangs-with-responses-larger-than-450kb