HTTP 500 Internal Server Error: Meaning and Fix

500 Internal Server Error

Meaning	The server hit an unexpected error.
When	An unhandled exception or a bug in the handler.
Causes	A null dereference, a failed assumption, or a bad deploy.
Fix	Read the server log for that request. The client cannot fix it by changing the payload unless the server bug is input-specific.
Retry	Retry idempotent requests a few times, then stop.
Alert?	Yes. A 500 on your service is something you should hear about.

Runs in your browser. Nothing you enter is stored.

Get pinged when your API starts returning 500s

A 500 on your service is something you should hear about.

curl -sS -X POST https://api.trigv.com/v1/events \
  -H "Content-Type: application/json" \
  -H "Accept: application/json" \
  -H "Authorization: Bearer $TRIGV_API_KEY" \
  -d '{"channel":"ops","title":"HTTP 500","level":"error"}'

Get an API key All status codes

How to use it

Read what 500 means before changing a retry loop.
Check the common causes against the response body and the server log.
Follow the retry note. Retrying a 400 with the same body will fail again.
If this is your API, use the snippet to hear about it.

About this tool

HTTP 500 Internal Server Error means The server hit an unexpected error. Servers send it when An unhandled exception or a bug in the handler.

Common causes: A null dereference, a failed assumption, or a bad deploy. The practical fix is: Read the server log for that request. The client cannot fix it by changing the payload unless the server bug is input-specific.

Retry: Retry idempotent requests a few times, then stop.

Alert on it? Yes. A 500 on your service is something you should hear about.

Trigv is a push for the moment a status starts mattering, not a log of every response. If the code is one you should hear about, the snippet posts a single event with level error or warning. The status page itself does not call your API.

Questions

What is HTTP 500?

The server hit an unexpected error.

Should the client retry?

Retry idempotent requests a few times, then stop.

Should I alert on it?

Yes. A 500 on your service is something you should hear about.

How is this different from reading the spec?

The page adds a plain retry note and an alert verdict for people running the service, not only for people parsing the response.

501 Not Implemented The server does not support this feature. 502 Bad Gateway A proxy got an invalid response from the upstream server. 503 Service Unavailable The server cannot handle the request right now. Cron Job Alert Script Wrap a command so a failed, slow, or finished cron job sends a Trigv alert.

HTTP 500 Internal Server Error