The APM PHP Agent can track most of the PHP errors, and capture the stacktrace for uncaught exceptions irrespective of the time taken by the transaction. We suggest changing the apdex and trace thresholds mainly for capturing trace on successful transactions.
You can view such uncaught exceptions in the Traces tab. Additionally, you can filter out the failed transactions in the transaction tab as well. Have attached the illustration below,
Clicking on the trace, will show you the details of that failed transaction. You can find the root cause of the error in the Exception sub-tab.
To view all the failed transaction trace from the Traces tab, use the "Errors" toggle and adjust the filter to view traces below the default value (2 sec).
Let us know if you have further requirements or if you are facing any difficulties tracking your errors. Kindly note that, APM would not be able to track segfaults as they mostly happen in the C run-time layer than in the language layers. We would recommend our log monitoring solution to track web server errors.
Thanks & Regards,
Developer, APM Insight