Error cases are not being logged

[pankajv82]

Hi,
We were able to recompile with new module (ngx_http_newrelic_module) for newrelic logging. We changed setting to Newrelic ON but all we getting HTTP 200 beeing logged although few APIs are failing. We don't see any error being logged. Error Rate is always 0%. Do we need to do something to enable error logging.

We are following below sample:
https://github.com/newrelic/agent_sdk_samples/blob/master/nginx/sample/conf/nginx.conf

We want to know what needs to be done to log cases when back-end API returns error (ex: HTTP 500. 401 etc)