I was conducting a load test for set of API calls and got a very small amount of network errors during the test. Although the number was insignificant what do the errors mean?
The errors are got are:
NL-NETWORK-03
java.net.ConnectionException: Connection refused: no further information
NL-NETWORK-01
java.io.IOException: Connection closed during ALPN negotiation.
The first error happens when the destination port is unreachable. The second error seems to be a SSL connection issue.
Depending on when it happened during your load test and if it occurred on multiple LG's (if it applies here) the root cause can be different. For example it can be the application server or any network devices between LG's and your application that is overloaded,
You can check if it can be correlated with higher response time from the application or with any counters from monitored infrastructure.
