Chapter 8
Using the CSS Scripting Language
Script Keepalive Examples
Example of a Custom TCP Script Keepalive with Graceful Socket
Close (FIN)
Note
OL-5647-02
The CSS provides scripted keepalives to support the need for keepalives
operations that cannot be handled using non-scripted keepalives. We recommend
that you limit I/O operations in a scripted keepalive to socket operations used to
probe network connectivity to a server and for determining application health on
a server. Although the scripting language supports file I/O on the CSS hard drive
or flash drive, we recommend that you do not use file I/O operations within
scripted keepalives. Extensive file I/O operations within scripted keepalives may
cause services to transition. File system access is allowed in scripts executed from
the CLI or from the command scheduler.
The following sections provide examples of script keepalives. You can use them
as is or modify them for your applications.
Use the following script keepalive to open and gracefully close (using a FIN rather
than a RST) a socket on user-specified TCP ports.
The service mode keepalive tcp-close fin command or global keepalive mode
tcp-close fin command also gracefully closes (using a FIN rather than a RST) a
socket.
!no echo
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
! Filename: ap-kal-tcp-ports
! Parameters: Service Address, TCP Port(s)
!
!Description:
! This script will open and close a socket on the user specified
! ports.
! The close will be a FIN rather than a RST. If one of the ports fails
! the service will be declared down
!
! Failure Upon:
! Not establishing a connection with the host on one of the specified
! ports.
Cisco Content Services Switch Administration Guide
Script Keepalive Examples
8-45