I want to know the meaning of some DMI Metrics.
I've searched the documentation in Dynatrace site but I didn't find it.
I want to learn about :
(1) What does the metrics "Discarded aborts" means?
(2) What's the difference between "TCP error" and "failure(TCP)" ?
Did I miss the answer in the documentation?
Thanks for the help!
Answer by Kris Z. ·
Discarded aborts is the number of aborted hits without valid server response. For example: client sent a request, server didn't respond with anything yet, client sent RST, connection has been closed. BTW, such situation will also bump the Session abort TCP error counter.
TCP error is accounted when server refused connection (RST from server instead of SYNACK), sever terminated connection (RST from server in the middle of the session), client terminates the connection (RST from client in the middle of the session), client doesn't respond (no ACK to server paste sent, so server terminates the connection with RST), serve doesn't respond (no ACK to packet sent by client, so client terminates the connection with RST).
Not all these TCP error conditions are actually failures that definitely affect the app-level communication (e.g. client session termination may be a legitimate signal that client is not interested in continuing response download - that's what happens when user navigates from one page to another before page load completed). Therefore, by default, only Connection refused or Connection establishment timeout errors. are accounted as failures.