Click on the MONITORING SCRIPTS link at the top of the page. The EDIT MONITORING SCRIPTS subsection allows the administrator to specify a send/expect string sequence to verify that the service for the virtual server is functional on each real server. It is also the place where the administrator can specify customized scripts to check services requiring dynamically changing data.

Figure 1.38. The EDIT MONITORING SCRIPTS Subsection

Sending Program
For more advanced service verification, you can use this field to specify the path to a service-checking script. This function is especially helpful for services that require dynamically changing data, such as HTTPS or SSL.
To use this function, you must write a script that returns a textual response, set it to be executable, and type the path to it in the Sending Program field.


If an external program is entered in the Sending Program field, then the Send field is ignored.
A string for the nanny daemon to send to each real server in this field. By default the send field is completed for HTTP. You can alter this value depending on your needs. If you leave this field blank, the nanny daemon attempts to open the port and assume the service is running if it succeeds.
Only one send sequence is allowed in this field, and it can only contain printable, ASCII characters as well as the following escape characters:
  • \n for new line.
  • \r for carriage return.
  • \t for tab.
  • \ to escape the next character which follows it.
The textual response the server should return if it is functioning properly. If you wrote your own sending program, enter the response you told it to send if it was successful.