Red Hat ENTERPRISE LINUX AS 2.1 Installation Manual page 148

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Send
Enter 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 char-
acters 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.
Sending Program
For more advanced service verification, you can use this field to specify the path to a service-
checking script. This functionality is especially helpful for services that require dynamically
changing data, such as HTTPS or SSL.
To use this functionality, you must write a script that returns a textual response, set it to be
executable, and type the path to it in the
Included in the
guide when composing an external service-checking script.
Expect
Chapter 9:Configuring the LVS Routers with Piranha Configuration Tool
To ensure that each server in the real server pool is checked, use the
special token %h after the path to the script in the
field. This token is replaced with each real server's IP address as the
script is called by the nanny daemon.
EDIT MONITORING SCRIPTS
If an external program is entered in the
the field is ignored.
Send
field.
Sending Program
Tip
subsection is a sample script you can use as a
Note
Sending Program
Sending Program
field, then