Tag Archives: 6.4d

6.4.d Implement and troubleshoot embedded event manager

6.4.d [i] EEM policy using applet

An EEM applet is a concise method for defining event screening criteria and the actions to be taken when that event occurs. In applet configuration mode, three types of configuration statements are supported. The event commands are used to specify the event criteria to trigger the applet to run, the action commands are used to specify an action to perform when the EEM applet is triggered, and the set command is used to set the value of an EEM applet variable. Currently only the _exit_status variable is supported for the set command when you use the sync option. Only one event configuration command is allowed within an applet configuration. When applet configuration mode is exited and no event command is present, a warning is displayed stating that no event is associated with this applet. If no event is specified, this applet is not considered registered. When no action is associated with this applet , events are still triggered but no actions are performed. Multiple action configuration commands are allowed within an applet configuration . Use the show event manager policy registered command to display a list of registered applets.

Before modifying an EEM applet, be aware that the existing applet is not replaced until you exit applet configuration mode. While you are in applet configuration mode modifying the applet, the existing applet may be executing. It is safe to modify the applet without unregistering it. When you exit applet configuration mode, the old applet is unregistered and the new version is registered.

The action configuration commands are uniquely identified using the label argument, which can be any string value. Actions are sorted in ascending alphanumeric key sequence using the label argument as the sort key, and they are run using this sequence. The Embedded Event Manager schedules and runs policies on the basis of an event specification that is contained within the policy itself. When applet configuration mode is exited, EEM examines the event and action commands that are entered and registers the applet to be run when a specified event occurs.

event manager applet applet-name

Above command registers the applet with the EEM and takes you to applet configuration mode for configuration of event criteria when there is a matching syslog message. The applet-name can be any case-sensitive alphanumeric string up to 29 characters.

Adam, Paul (2014-07-12). All-in-One CCIE V5 Written Exam Guide (Kindle Locations 6197-6205).  . Kindle Edition.

http://www.cisco.com/c/en/us/td/docs/ios/netmgmt/configuration/guide/12_2sx/nm_12_2sx_book/nm_eem_policy_cli.html#wp1064344

6.4.d Implement and troubleshoot embedded event manager

embedded event manager, from your friendly neighborhood doc cd:

http://www.cisco.com/en/US/docs/ios-xml/ios/eem/configuration/12-4t/eem-overview.html

EEM is a flexible, policy-driven framework that supports in-box monitoring of different components of the system with the help of software agents known as event detectors. The figure below shows the relationship between the EEM server, core event publishers (event detectors), and the event subscribers (policies). Basically, event publishers screen events and publish them when there is a match on an event specification that is provided by the event subscriber. Event detectors notify the EEM server when an event of interest occurs. The EEM policies that are configured using the Cisco IOS command-line interface (CLI) then implement recovery on the basis of the current state of the system and the actions specified in the policy for the given event.

EEM offers the ability to monitor events and take informational or corrective action when the monitored events occur or when a threshold is reached. An EEM policy is an entity that defines an event and the actions to be taken when that event occurs. There are two types of EEM policies: an applet or a script. An applet is a simple form of policy that is defined within the CLI configuration. A script is a form of policy that is written in Tool Command Language (Tcl).