Measures reported by TcpPortTest

This operating system-specific test periodically tracks the status of TCP connections to and from a server. This test can be used in different ways. For instance, an administrator can use this test to determine the number of connections that currently exist to a specific TCP port on the server (e.g., the web server port). Alternately, the administrator can also determine the number of TCP connections established from one server to another server - for example, from a web server to a specific application server.

To use the TcpPortTest, an administrator should specify a list of TCP source/port or destination/port combinations that he/she is interested in monitoring. For each such combination, the TcpPortTest reports the number of TCP connections in each of the TCP protocol states. Analysis of the results can point to scenarios that need attention - e.g., abnormally high established connections to a specific TCP port, unusually large number of connections in the FIN_WAIT state, etc. Often in multi-tier infrastructures that include a number of inter-dependent application tiers, it is also interesting to compare the number of connections established to each tier and correlate the increase/decrease of connections across tiers.