Editing Cluster and its component Understanding (section)

==== ⁠1.10.4.3. EDIT MONITORING SCRIPTS Subsection ====
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. 

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[[Image:monitoring-scripts-sub.png]]

'''Figure&nbsp;1.34.&nbsp;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. 

'''Note'''

If an external program is entered in the '''Sending Program''' field, then the '''Send''' field is ignored. 

'''Send'''

A string for the <tt>nanny</tt> 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 <tt>nanny</tt> 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. 

'''Expect'''

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. 


[https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/5/html-single/Cluster_Suite_Overview/index.html#idp9665488 [1] ]A virtual server is a service configured to listen on a specific virtual IP. = ⁠Chapter 2. Red Hat Cluster Suite Component Summary =
[https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/5/html-single/Cluster_Suite_Overview/index.html#s1-ha-components-CSO 2.1. Cluster Components]

[https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/5/html-single/Cluster_Suite_Overview/index.html#s1-man-pages-CSO 2.2. Man Pages]

[https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/5/html-single/Cluster_Suite_Overview/index.html#s1-hw-compat-CSO 2.3. Compatible Hardware]

This chapter provides a summary of Red Hat Cluster Suite components and consists of the following sections: 

* [https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/5/html-single/Cluster_Suite_Overview/index.html#s1-ha-components-CSO Section 2.1, “Cluster Components”] 
* [https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/5/html-single/Cluster_Suite_Overview/index.html#s1-man-pages-CSO Section 2.2, “Man Pages”] 
* [https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/5/html-single/Cluster_Suite_Overview/index.html#s1-hw-compat-CSO Section 2.3, “Compatible Hardware”]