The Service Monitor checks the health of each Service and Real Server on an ongoing basis. Specify which test to perform and how frequently to do the test by editing the Service or Real Server on the BASIC > Services page. The BASIC > Services and BASIC > Server Health pages display the health of all load-balanced Services and associated Real Servers.
There are many different methods available to establish the availability of a Service or Real Server. These include TCP port check, HTTP GET request, DNS query and RADIUS test. The various tests are fully documented in the online help.
The tests always use the configured Real Server port for the Service unless the Real Server port is set to ALL. In that case, the tests use the default port for the test type (e.g. SMTP = 25, HTTP = 80, DNS = 53, HTTPS = 443, IMAP = 143, POP = 110 and SNMP = 161).
If a Real Server is associated with more than one Service, but with the same test and test interval for each Service, it will be tested once per test interval. Otherwise, it may be checked more frequently. Unless the tests are identical, the Service Monitor performs its health checks for each Service’s set of Real Servers independently.
Monitor groups are sets of tests that are conducted on Real Servers. Use them when one test does not give a complete picture of the health of a Real Server. You can specify a monitoring group with two or more tests and the Service Monitor will perform all the tests in the group. The failure of any one test means the Real Server is considered to be unavailable and it will be removed from the load-balancing pool.
Create monitor groups that contain one or more tests on the ADVANCED > Monitor Groups page. Then edit the Real Server or Service. The monitor groups appear in the Testing Methods for the Service Detail or Real Server Detail page.