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This module describes how to write Embedded Event Manager (EEM) policies using Cisco IOS XE software command-line interface (CLI) applets to handle Cisco IOS XE software faults and events. EEM is a distributed and customized approach to event detection and recovery offered directly in a Cisco IOS device. EEM offers the ability to monitor events and take informational, corrective, or any desired action when the monitored events occur or when a threshold is reached. The EEM policy engine receives notifications when faults and other events occur. EEM policies implement recovery on the basis of the current state of the system and the actions specified in the policy for a given event. Recovery actions are triggered when the policy is run.
For the latest feature information and caveats, see the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the "Feature Information for Writing EEM Policies Using the Cisco IOS XE Software CLI" section.
Use Cisco Feature Navigator to find information about platform support and Cisco IOS XE software image support. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.
•Prerequisites for Writing EEM Policies Using the Cisco IOS XE Software CLI
•Information About Writing EEM Policies Using the Cisco IOS XE Software CLI
•How to Write EEM Policies Using the Cisco IOS XE Software CLI
•Configuration Examples for Writing EEM Policies Using the Cisco IOS CLI
•Feature Information for Writing EEM Policies Using the Cisco IOS XE Software CLI
•Before writing EEM policies, you should be familiar with the concepts explained in the "Embedded Event Manager Overview" module.
•If the action cns-event command is used, access to a CNS Event gateway must be configured.
•If the action force-switchover command is used, a secondary processor must be configured on the device.
•If the action snmp-trap command is used, the snmp-server enable traps event-manager command must be enabled to permit SNMP traps to be sent from the Cisco IOS XE software device to the SNMP server. Other relevant snmp-server commands must also be configured; for details see the action snmp-trap command page.
To write EEM policies using the Cisco IOS XE software CLI, you should understand the following concepts:
•Embedded Event Manager Policies
•EEM Actions Available by Cisco IOS XE Software Release
•Embedded Event Manager Built-In Environment Variables Used in EEM Applets
EEM offers the ability to monitor events and take informational or corrective action when the monitored events occur or 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).
EEM 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.
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.
EEM Script
Scripts are defined off the networking device using an ASCII editor. The script is then copied to the networking device and registered with EEM. Tcl scripts are supported by EEM.
EEM allows you to write and implement your own policies using Tcl. Writing an EEM policy involves:
•Selecting the event for which the policy is run.
•Defining the event detector options associated with logging and responding to the event.
•Choosing the actions to be followed when the event occurs.
Cisco provides enhancements to Tcl in the form of keyword extensions that facilitate the development of EEM policies. The main categories of keywords identify the detected event, the subsequent action, utility information, counter values, and system information. For more details about writing EEM policies using Tcl, see the "Writing Embedded Event Manager Policies Using Tcl" module.
The CLI-based corrective actions that are taken when event detectors report events enable a powerful on-device event management mechanism. The following actions are available for Cisco IOS XE software releases:
•Execute a CLI command
•Generate a CNS event
•Set or modify a named counter
•Switch to a secondary RP
•Request system information
•Send a short e-mail
•Manually run an EEM policy
•Publish an application-specific event
•Reload the Cisco IOS XE software
•Generate an SNMP trap
•Generate a prioritized syslog message
For more details on each action, see the Embedded Event Manager Actions concept in the "Embedded Event Manager Overview" module.
EEM built-in environment variables are a subset of the Cisco-defined environment variables and the built-in variables are available to EEM applets only. The built-in variables can be read-only or can be read and write and these variables may apply to one specific event detector or to all event detectors. Table 1 lists the Cisco built-in environment variables that are read-only alphabetically by event detector and subevent.
This section contains the following tasks:
•Registering and Defining an Embedded Event Manager Applet
•Registering and Defining an Embedded Event Manager Policy to Run Manually
•Unregistering Embedded Event Manager Policies
•Suspending Embedded Event Manager Policy Execution
•Configuring and Tracking a Stub Object Using Embedded Event Manager
•Displaying Embedded Event Manager History Data
•Displaying Embedded Event Manager Registered Policies
Perform this task to register an applet with Embedded Event Manager and to define the EEM applet using the Cisco IOS XE software CLI event and action commands. Only one event command is allowed in an EEM applet. Multiple action commands are permitted. If no event and no action commands are specified, the applet is removed when you exit configuration mode.
The SNMP event detector and the syslog action commands used in this task are just representing any event detector and action commands. For examples using other event detectors and action commands, see the "Embedded Event Manager Applet Configuration: Examples" section.
EEM environment variables for EEM policies are defined using the EEM event manager environment configuration command. By convention, all Cisco EEM environment variables begin with "_". In order to avoid future conflict, customers are urged not to define new variables that start with "_".
You can display the EEM environment variables set on your system by using the show event manager environment privileged EXEC command.
For example, you can create EEM policies that can send e-mails when an event occurs. Table 2 describes the e-mail-specific environment variables that can be used in EEM policies.
An EEM action label is a unique identifier that can be any string value. Actions are sorted and run in ascending alphanumeric (lexicographical) key sequence using the label as the sort key. If you are using numbers as labels be aware that alphanumerical sorting will sort 10.0 after 1.0, but before 2.0, and in this situation we recommend that you use numbers such as 01.0, 02.0, and so on, or use an initial letter followed by numbers.
1. enable
2. show event manager environment [all | variable-name]
3. configure terminal
4. event manager environment variable-name string
5. Repeat Step 4 for all the required environment variables.
6. event manager applet applet-name
7. event snmp oid oid-value get-type {exact | next} entry-op operator entry-val entry-value [exit-comb {or | and}] [exit-op operator] [exit-val exit-value] [exit-time exit-time-value] poll-interval poll-int-value
8. action label cli command cli-string [pattern pattern-string]
9. action label syslog [priority priority-level] msg msg-text
10. action label mail server server-address to to-address from from-address [cc cc-address] subject subject body body-text
11. Add more action commands as required.
12. end
|
|
|
---|---|---|
Step 1 |
enable Router> enable |
Enables privileged EXEC mode. •Enter your password if prompted. |
Step 2 |
show event manager environment [all | variable-name] Router# show event manager environment all |
(Optional) Displays the name and value of EEM environment variables. •The optional all keyword displays all the EEM environment variables. •The optional variable-name argument displays information about the specified environment variable. |
Step 3 |
configure terminal Router# configure terminal |
Enters global configuration mode. |
Step 4 |
event manager environment variable-name string Router(config)# event manager environment _email_to engineering@example.com |
Configures the value of the specified EEM environment variable. •In this example, the environment variable that holds the e-mail address to which e-mail is sent is set to engineering@example.com. |
Step 5 |
Repeat Step 4 for all the required environment variables. |
Repeat Step 4 to configure all the environment variables required by the policy to be registered in Step 6. |
Step 6 |
event manager applet applet-name Router(config)# event manager applet memory-fail |
Registers the applet with the Embedded Event Manager (EEM) and enters applet configuration mode. |
Step 7 |
event snmp oid oid-value get-type {exact | next} entry-op operator entry-val entry-value [exit-comb {or | and}] [exit-op operator] [exit-val exit-value] [exit-time exit-time-value] poll-interval poll-int-value Router(config-applet)# event snmp oid 1.3.6.1.4.1.9.9.48.1.1.1.6.1 get-type exact entry-op lt entry-val 5120000 poll-interval 90 |
Specifies the event criteria that cause the EEM applet to run. •In this example, an EEM event is triggered when free memory falls below the value of 5120000. •Exit criteria are optional, and if not specified, event monitoring is reenabled immediately. |
Step 8 |
action label cli command cli-string [pattern pattern-string] Router(config-applet)# event cli command {.*interface loopback*} sync yes occurs 3 Router(config-applet)# action 1.0 cli command "no shutdown" Router(config-applet)# action 1.0 cli command "enable" Router(config-applet)# action 2.0 cli command "clear counters Ethernet0/1" pattern "confirm" Router(config-applet)# action 3.0 cli command "y" |
Specifies the action of executing a Cisco IOS XE software CLI command when an EEM applet is triggered. The pattern keyword is optional and is used only when the command string solicits input. The action cli command ends when the solicited prompt as specified in the optional pattern keyword is received. The user is required to specify a regular expression pattern that will match the next solicited prompt. Specification of an incorrect pattern will cause the action cli command to wait forever until the applet execution times out due to the maxrun timer expiration. •In the first example, the action taken is to specify an EEM applet to run when the Cisco IOS XE software interface loopback CLI command is configured three times. The applet executes the no shutdown command to ensure that the loopback interfaces are operational. •In the second example, the action taken is to specify an EEM applet to run when the pattern keyword specifies the confirm argument for the clear counters Ethernet0/1 command. In this case the command string solicits input, such as "confirm," which has to be completed with a "yes" or a "no" input. |
Step 9 |
action label syslog [priority priority-level] msg msg-text Router(config-applet)# action 1.0 syslog priority critical msg "Memory exhausted; current available memory is $_snmp_oid_val bytes" |
Specifies the action to be taken when an EEM applet is triggered. •In this example, the action to be taken is to write a message to syslog. •The optional priority keyword specifies the priority level of the syslog messages. If selected, the priority-level argument must be defined. •The msg-text argument can be character text, an environment variable, or a combination of the two. |
Step 10 |
action label mail server server-address to to-address from from-address [cc cc-address] subject subject body body-text Router(config-applet)# action 2.0 mail server 192.168.1.10 to engineering@example.com from devtest@example.com subject "Memory failure" body "Memory exhausted; current available memory is $_snmp_oid_val bytes" |
Specifies the action of sending a short e-mail when an EEM applet is triggered. •The server-address argument specifies the fully qualified domain name of the e-mail server to be used to forward the e-mail. •The to-address argument specifies the e-mail address where the e-mail is to be sent. •The from-address argument specifies the e-mail address from which the e-mail is sent. •The subject argument specifies the subject line content of the e-mail as an alphanumeric string. •The body-text argument specifies the text content of the e-mail as an alphanumeric string. |
Step 11 |
Add more action commands as required. |
— |
Step 12 |
end Router(config-applet)# end |
Exits applet configuration mode and returns to privileged EXEC mode. |
Use the debug event manager command in privileged EXEC mode to troubleshoot EEM command operations. Use any debugging command with caution as the volume of generated output can slow or stop the router operations. We recommend that this command be used only under the supervision of a Cisco engineer.
There are two ways to manually run an EEM policy. EEM usually schedules and runs policies on the basis of an event specification that is contained within the policy itself. The event none command allows EEM to identify an EEM policy that can be manually triggered. To run the policy, use either the action policy command in applet configuration mode or the event manager run command in privileged EXEC mode.
Perform this task to register an EEM policy to be run manually using the event manager run command. For an example of how to manually run a policy using the action policy command, see the "Embedded Event Manager Manual Policy Execution: Examples" section.
1. enable
2. configure terminal
3. event manager applet applet-name
4. event none
5. action label syslog [priority priority-level] msg msg-text
6. end
7. event manager run applet-name
Perform this task to remove an EEM policy from the running configuration file. Execution of the policy is canceled.
1. enable
2. show event manager policy registered [event-type event-name] [system | user] [time-ordered | name-ordered]
3. configure terminal
4. no event manager policy policy-filename
5. exit
6. Repeat Step 2 to ensure that the policy has been removed.
|
|
|
---|---|---|
Step 1 |
enable Router> enable |
Enables privileged EXEC mode. •Enter your password if prompted. |
Step 2 |
show event manager policy registered [event-type event-name] [system | user] [time-ordered | name-ordered] Router# show event manager policy registered |
(Optional) Displays the EEM policies that are currently registered. •The optional system and user keywords display the registered system and user policies. •If no keywords are specified, EEM registered policies for all event types are displayed in time order. |
Step 3 |
configure terminal Router# configure terminal |
Enters global configuration mode. |
Step 4 |
no event manager policy policy-filename Router(config)# no event manager policy IPSLAping1 |
Removes the EEM policy from the configuration, causing the policy to be unregistered. |
Step 5 |
exit Router(config)# exit |
Exits global configuration mode and returns to privileged EXEC mode. |
Step 6 |
Repeat Step 2 to ensure that the policy has been removed. Router# show event manager policy registered |
— |
In the following example, the show event manager policy registered privileged EXEC command is used to display the two EEM applets that are currently registered:
Router# show event manager policy registered
No. Class Type Event Type Trap Time Registered Name
1 applet system snmp Off Fri Aug 12 17:42:52 2005 IPSLAping1
oid {1.3.6.1.4.1.9.9.42.1.2.9.1.6.4} get-type exact entry-op eq entry-val {1}
exit-op eq exit-val {2} poll-interval 90.000
action 1.0 syslog priority critical msg "Server IPecho Failed: OID=$_snmp_oid_val"
action 1.1 snmp-trap strdata "EEM detected server reachability failure to 10.1.88.9"
action 1.2 publish-event sub-system 88000101 type 1 arg1 "10.1.88.9" arg2 "IPSLAEcho"
arg3 "fail"
action 1.3 counter name _IPSLA1F op inc value 1
2 applet system snmp Off Thu Sep 15 05:57:16 2005 memory-fail
oid {1.3.6.1.4.1.9.9.48.1.1.1.6.1} get-type exact entry-op lt entry-val {5120000} poll-interval 90
action 1.0 syslog priority critical msg Memory exhausted; current available memory is $_snmp_oid_val bytes
action 2.0 force-switchover
In the following example, the show event manager policy registered privileged EXEC command is used to show that applet IPSLAping1 has been removed after entering the no event manager policy command:
Router# show event manager policy registered
No. Class Type Event Type Trap Time Registered Name
1 applet system snmp Off Thu Sep 15 05:57:16 2005 memory-fail
oid {1.3.6.1.4.1.9.9.48.1.1.1.6.1} get-type exact entry-op lt entry-val {5120000} poll-interval 90
action 1.0 syslog priority critical msg Memory exhausted; current available memory is $_snmp_oid_val bytes
action 2.0 force-switchover
Perform this task to immediately suspend the execution of all EEM policies. Suspending policies, instead of unregistering them might be necessary for reasons of temporary performance or security.
1. enable
2. show event manager policy registered [event-type event-name] [system | user] [time-ordered | name-ordered]
3. configure terminal
4. event manager scheduler suspend
5. exit
Perform this task to create a stub object, set the state of the stub object, and configure an EEM applet to be run when the tracked object changes. Actions are specified within the EEM applet to both set and read the state of the object. This task allows EEM to define an enhanced object tracking (EOT) object that may be manipulated by other EOT clients. An EEM policy can be a trigger for any EOT object including objects defined for other EOT clients or for an object defined by EEM.
Object tracking was first introduced into the Hot Standby Router Protocol (HSRP) as a simple tracking mechanism that allowed you to track the interface line-protocol state only. Enhanced object tracking provides complete separation between the objects to be tracked and the action to be taken by a client when a tracked object changes. Thus, several clients such as EEM, VRRP, or GLBP can register their interest with the tracking process, track the same object, and each take different action when the object changes.
Each tracked object is identified by a unique number that is specified on the tracking command-line interface (CLI). Client processes use this number to track a specific object. The tracking process periodically polls the tracked objects and notes any change of value. The changes in the tracked object are communicated to interested client processes, either immediately or after a specified delay. The object values are reported as either up or down.
The EOT event detector publishes an event when the tracked object changes.
1. enable
2. configure terminal
3. track object-number stub-object
4. default-state {up | down}
5. exit
6. event manager applet applet-name
7. event [label] track object-number [state {up | down | any}]
8. action label track set object-number state {up | down}
9. action label track read object-number
10. end
11. show track [object-number [brief]]
In the following example, the show track privileged EXEC command is used to display information about tracked object number 2.
Router# show track 2
Track 2
Stub-object
State is Up
1 change, last change 00:00:04, by Undefined
Perform this optional task to change the size of the history tables and to display EEM history data.
1. enable
2. configure terminal
3. event manager history size {events | traps} [size]
4. exit
5. show event manager history events [detailed] [maximum number]
6. show event manager history traps {server | policy}
Step 1 enable
Enables privileged EXEC mode. Enter your password if prompted.
Router> enable
Step 2 configure terminal
Enters global configuration mode.
Router# configure terminal
Step 3 event manager history size {events | traps} [size]
Use this command to change the size of the EEM event history table or the size of the EEM SNMP trap history table. In the following example, the size of the EEM event history table is changed to 30 entries:
Router(config)# event manager history size events 30
Step 4 exit
Exits global configuration mode and returns to privileged EXEC mode.
Router(config)# exit
Step 5 show event manager history events [detailed] [maximum number]
Use this command to display detailed information about each EEM event, for example:
Router# show event manager history events
No. Time of Event Event Type Name
1 Fri Aug13 21:42:57 2004 snmp applet: SAAping1
2 Fri Aug13 22:20:29 2004 snmp applet: SAAping1
3 Wed Aug18 21:54:48 2004 snmp applet: SAAping1
4 Wed Aug18 22:06:38 2004 snmp applet: SAAping1
5 Wed Aug18 22:30:58 2004 snmp applet: SAAping1
6 Wed Aug18 22:34:58 2004 snmp applet: SAAping1
7 Wed Aug18 22:51:18 2004 snmp applet: SAAping1
8 Wed Aug18 22:51:18 2004 application applet: CustApp1
Step 6 show event manager history traps {server | policy}
Use this command to display the EEM SNMP traps that have been sent either from the EEM server or from an EEM policy. In the following example, the EEM SNMP traps that were triggered from within an EEM policy are displayed.
Router# show event manager history traps policy
No. Time Trap Type Name
1 Wed Aug18 22:30:58 2004 policy EEM Policy Director
2 Wed Aug18 22:34:58 2004 policy EEM Policy Director
3 Wed Aug18 22:51:18 2004 policy EEM Policy Director
Perform this optional task to display registered EEM policies.
1. enable
2. show event manager policy registered [event-type event-name] [time-ordered | name-ordered]
Step 1 enable
Enables privileged EXEC mode. Enter your password if prompted.
Router> enable
Step 2 show event manager policy registered [event-type event-name] [time-ordered | name-ordered]
Use this command with the time-ordered keyword to display information about currently registered policies sorted by time, for example:
Router# show event manager policy registered time-ordered
No. Type Event Type Time Registered Name
1 applet snmp Thu May30 05:57:16 2004 memory-fail
oid {1.3.6.1.4.1.9.9.48.1.1.1.6.1} get-type exact entry-op lt entry-val {5120000} poll-interval 90
action 1.0 syslog priority critical msg "Memory exhausted; current available memory is $_snmp_oid_val bytes"
action 2.0 force-switchover
2 applet syslog Wed Jul16 00:05:17 2004 intf-down
pattern {.*UPDOWN.*Ethernet1/0.*}
action 1.0 cns-event msg "Interface state change: $_syslog_msg"
Use this command with the name-ordered keyword to display information about currently registered policies sorted by name, for example:
Router# show event manager policy registered name-ordered
No. Type Event Type Time Registered Name
1 applet syslog Wed Jul16 00:05:17 2004 intf-down
pattern {.*UPDOWN.*Ethernet1/0.*}
action 1.0 cns-event msg "Interface state change: $_syslog_msg"
2 applet snmp Thu May30 05:57:16 2004 memory-fail
oid {1.3.6.1.4.1.9.9.48.1.1.1.6.1} get-type exact entry-op lt entry-val {5120000} poll-interval 90
action 1.0 syslog priority critical msg "Memory exhausted; current available memory is $_snmp_oid_val bytes"
action 2.0 force-switchover
Use this command with the event-type keyword to display information about currently registered policies for the event type specified in the event-name argument, for example:
Router# show event manager policy registered event-type syslog
No. Type Event Type Time Registered Name
1 applet syslog Wed Jul16 00:05:17 2004 intf-down
pattern {.*UPDOWN.*Ethernet1/0.*}
action 1.0 cns-event msg "Interface state change: $_syslog_msg"
This section contains the following configuration examples:
•Embedded Event Manager Applet Configuration: Examples
•Embedded Event Manager Manual Policy Execution: Examples
•Configuring and Tracking a Stub Object Using Embedded Event Manager: Example
•Embedded Event Manager Watchdog System Monitor Event Detector Configuration: Example
The following examples show how to create an EEM applet for some of the EEM event detectors. These examples follow steps outlined in the "Registering and Defining an Embedded Event Manager Applet" section.
Application-Specific Event Detector
The following example shows how a policy named EventPublish_A runs every 20 seconds and publishes an event type numbered 1 to an EEM subsystem numbered 798. The subsystem value of 798 specifies that a publish event has occurred from an EEM policy. A second policy named EventPublish_B is registered to run when the EEM event type 1 occurs with subsystem 798. When the EventPublish_B policy runs, it sends a message to syslog containing data passed as an argument from the EventPublish_A policy.
event manager applet EventPublish_A
event timer watchdog time 20.0
action 1.0 syslog msg "Applet EventPublish_A"
action 2.0 publish-event sub-system 798 type 1 arg1 twenty
exit
event manager applet EventPublish_B
event application sub-system 798 type 1
action 1.0 syslog msg "Applet EventPublish_B arg1 $_application_data1"
CLI Event Detector
The following example shows how to specify an EEM applet to run when the Cisco IOS XE software write memory CLI command is run. The applet provides a notification that this event has occurred via a syslog message. In the example, the sync keyword is configured with the yes argument, and this means that the event detector is notified when this policy completes running. The exit status of the policy determines whether the CLI command will be executed. In this example, the policy exit status is set to one and the CLI command runs.
event manager applet cli-match
event cli pattern "write mem.*" sync yes
action 1.0 syslog msg "$_cli_msg Command Executed"
set 2.0 _exit_status 1
The following example shows an applet which matches the cli pattern with the test argument. When show access-list test is entered, the CLI event detector matches the test argument, and the applet is triggered. The debug event manager detector cli output is added to show num matches is set to one.
!
event manager applet EEM-PIPE-TEST
event cli pattern "test" sync yes
action 1.0 syslog msg "Pattern matched!"
!
*Aug 23 23:19:59.827: check_eem_cli_policy_handler: command_string=show access-lists test
*Aug 23 23:19:59.827: check_eem_cli_policy_handler: num_matches = 1, response_code = 4
*Aug 23 23:19:59.843: %HA_EM-6-LOG: EEM-PIPE-TEST: Pattern matched!
Note The functionality provided in the CLI event detector only allows a regular expression pattern match on a valid IOS CLI command itself. This does not include text after a pipe (|) character when redirection is used.
The following example shows that when show version | include test is entered, the applet fails to trigger because the CLI event detector does not match on characters entered after the pipe (|) character and the debug event manager detector cli output shows num matches is set to zero.
*Aug 23 23:20:16.827: check_eem_cli_policy_handler: command_string=show version
*Aug 23 23:20:16.827: check_eem_cli_policy_handler: num_matches = 0, response_code = 1
Counter Event Detector and Timer Event Detector
The following example shows that the EventCounter_A policy is configured to run once a minute and to increment a well-known counter called critical_errors. A second policy—EventCounter_B—is registered to be triggered when the well-known counter called critical_errors exceeds a threshold of 3. When the EventCounter_B policy runs, it resets the counter to 0.
event manager applet EventCounter_A
event timer watchdog time 60.0
action 1.0 syslog msg "EventCounter_A"
action 2.0 counter name critical_errors op inc value 1
exit
event manager applet EventCounter_B
event counter name critical_errors entry-op gt entry-val 3 exit-op lt exit-val 3
action 1.0 syslog msg "EventCounter_B"
action 2.0 counter name critical_errors op set value 0
Interface Counter Event Detector
The following example shows how a policy named EventInterface is triggered every time the receive_throttle counter for Fast Ethernet interface 0/0 is incremented by 5. The polling interval to check the counter is specified to run once every 90 seconds.
event manager applet EventInterface
event interface name FastEthernet0/0 parameter receive_throttle entry-op ge entry-val 5
entry-val-is-increment true poll-interval 90
action 1.0 syslog msg "Applet EventInterface"
Resource Event Detector
The following example shows how to specify event criteria based on an ERM event report for a policy defined to report high CPU usage:
event manager applet policy-one
event resource policy cpu-high
action 1.0 syslog msg "CPU high at $_resource_current_value percent"
RF Event Detector
The RF event detector is only available on networking devices that contain dual Route Processors (RPs). The following example shows how to specify event criteria based on an RF state change notification:
event manager applet start-rf
event rf event rf_prog_initialization
action 1.0 syslog msg "rf state rf_prog_initialization reached"
Syslog Event Detector
The following example shows how to specify an EEM applet to run when syslog identifies that FastEthernet interface 1/0 is down. The applet sends a message about the interface to syslog.
event manager applet interface-down
event syslog pattern ".*UPDOWN.*FastEthernet1/0.*" occurs 4
action 1.0 syslog msg "FastEthernet interface 1/0 changed state 4 times"
SNMP Event Detector
The following example shows how to specify an EEM applet to run when the CPU usage is greater than 75 percent. When the EEM applet runs, the CLI commands enable and show cpu processes are run, and an e-mail containing the result of the show cpu processes command is sent to an engineer.
event manager applet snmpcpuge75
event snmp oid 1.3.6.1.4.1.9.9.109.1.1.1.1.3.1 get-type exact entry-op ge entry-val 75 poll-interval 10
action 1.0 cli command "enable"
action 2.0 cli command "show process cpu"
action 3.0 mail server "192.168.1.146" to "engineer@cisco.com" from "devtest@cisco.com" subject "B25 PBX Alert" body "$_cli_result"
The next example is more complex and shows how to configure an EEM applet that causes a switch to the secondary (redundant) Route Processor (RP) when the primary RP runs low on memory.
This example illustrates a method for taking preventative action against a software fault that causes a memory leak. The action taken here is designed to reduce downtime by switching over to a redundant RP when a possible memory leak is detected.
Figure 1 Dual RP Topology
The commands used to register the policy are shown below.
event manager applet memory-demo
event snmp oid 1.3.6.1.4.1.9.9.48.1.1.1.6.1 get-type exact entry-op lt entry-val 5120000 poll-interval 90
action 1.0 syslog priority critical msg "Memory exhausted; current available memory is $_snmp_oid_val bytes"
action 2.0 force-switchover
The registered applet is displayed using the show event manager policy registered command:
Router# show event manager policy registered
No. Type Event Type Time Registered Name
1 applet snmp Thu Jan30 05:57:16 2003 memory-demo
oid {1.3.6.1.4.1.9.9.48.1.1.1.6.1} get-type exact entry-op lt entry-val {5120000} poll-interval 90
action 1.0 syslog priority critical msg "Memory exhausted; current available memory is $_snmp_oid_val bytes"
action 2.0 force-switchover
For the purpose of this example, a memory depletion is forced on the router, and a series of show memory commands are executed to watch the memory deplete:
Router# show memory
Head Total(b) Used(b) Free(b) Lowest(b) Largest(b)
Processor 53585260 212348444 119523060 92825384 92825384 92365916
Fast 53565260 131080 70360 60720 60720 60668
Router# show memory
Head Total(b) Used(b) Free(b) Lowest(b) Largest(b)
Processor 53585260 212364664 164509492 47855172 47855172 47169340
Fast 53565260 131080 70360 60720 60720 60668
Router# show memory
Head Total(b) Used(b) Free(b) Lowest(b) Largest(b)
Processor 53585260 212369492 179488300 32881192 32881192 32127556
Fast 53565260 131080 70360 60720 60720 60668
When the threshold is reached, an EEM event is triggered. The applet named memory-demo runs, causing a syslog message to be written to the console and a switch to be made to the secondary RP. The following messages are logged:
00:08:31: %HA_EM-2-LOG: memory-demo: Memory exhausted; current available memory is 4484196 bytes
00:08:31: %HA_EM-6-FMS_SWITCH_HARDWARE: fh_io_msg: Policy has requested a hardware switchover
The following is partial output from the show running-config command on both the primary RP and the secondary (redundant) RP:
redundancy
mode sso
.
.
!
event manager applet memory-demo
event snmp oid 1.3.6.1.4.1.9.9.48.1.1.1.6.1 get-type exact entry-op lt entry-val 5120000 poll-interval 90
action 1.0 syslog priority critical msg "Memory exhausted; current available memory is $_snmp_oid_val bytes"
action 2.0 force-switchover
The following examples show how to use the none event detector to configure an EEM policy (applet or script) to be run manually.
Using the event manager run Command
This example shows how to run a policy manually using the event manager run command. The policy is registered using the event none command under applet configuration mode and then run from global configuration mode using the event manager run command.
event manager applet manual-policy
event none
action 1.0 syslog msg "Manual-policy triggered"
end
!
event manager run manual-policy
Using the action policy Command
This example shows how to run a policy manually using the action policy command. The policy is registered using the event none command under applet configuration mode, and then the policy is executed using the action policy command in applet configuration mode.
event manager applet manual-policy
event none
action 1.0 syslog msg "Manual-policy triggered"
exit
!
event manager applet manual-policy-two
event none
action 1.0 policy manual-policy
end
!
event manager run manual-policy-two
This example shows how to create a stub object, set the state of the stub object, and configure an EEM applet to be run when the tracked object changes. The enhanced object tracking (EOT) event detector is used, and actions are specified to both set and read the state of the object. This example allows EEM to define an EOT object that may be manipulated by other EOT clients. An EEM policy can be a trigger for any EOT object including objects defined for other EOT clients or for an object defined by EEM.
track 10 stub-object
default-state down
!
event manager applet track-ten
event track 10 state any
action 1.0 track set 10 state up
action 2.0 track read 10
The following example shows how to configure three EEM applets to demonstrate how the Cisco IOS XE software watchdog system monitor (IOSWDSysMon) event detector works.
Watchdog System Monitor Sample1 Policy
The first policy triggers an applet when the average CPU usage for the process named IP Input is greater than or equal to 1 percent for 10 seconds:
event manager applet IOSWD_Sample1
event ioswdsysmon sub1 cpu-proc taskname "IP Input" op ge val 1 period 10
action 1.0 syslog msg "IOSWD_Sample1 Policy Triggered"
Watchdog System Monitor Sample2 Policy
The second policy triggers an applet when the total amount of memory used by the process named Net Input is greater than 100 kb:
event manager applet IOSWD_Sample2
event ioswdsysmon sub1 mem-proc taskname "Net Input" op gt val 100 is-percent false
action 1.0 syslog msg "IOSWD_Sample2 Policy Triggered"
Watchdog System Monitor Sample3 Policy
The third policy triggers an applet when the total amount of memory used by the process named IP RIB Update has increased by more than 50 percent over the sample period of 60 seconds:
event manager applet IOSWD_Sample3
event ioswdsysmon sub1 mem-proc taskname "IP RIB Update" op gt val 50 is-percent true period 60
action 1.0 syslog msg "IOSWD_Sample3 Policy Triggered"
The three policies are configured, and then repetitive large pings are made to the networking device from several workstations, causing the networking device to register some usage. This will trigger policies 1 and 2, and the console will display the following messages:
00:42:23: %HA_EM-6-LOG: IOSWD_Sample1: IOSWD_Sample1 Policy Triggered
00:42:47: %HA_EM-6-LOG: IOSWD_Sample2: IOSWD_Sample2 Policy Triggered
To view the policies that are registered, use the show event manager policy registered command:
Router# show event manager policy registered
No. Class Type Event Type Trap Time Registered Name
1 applet system ioswdsysmon Off Fri Jul 23 02:27:28 2004 IOSWD_Sample1
sub1 cpu_util {taskname {IP Input} op ge val 1 period 10.000 }
action 1.0 syslog msg "IOSWD_Sample1 Policy Triggered"
2 applet system ioswdsysmon Off Fri Jul 23 02:23:52 2004 IOSWD_Sample2
sub1 mem_used {taskname {Net Input} op gt val 100 is_percent FALSE}
action 1.0 syslog msg "IOSWD_Sample2 Policy Triggered"
3 applet system ioswdsysmon Off Fri Jul 23 03:07:38 2004 IOSWD_Sample3
sub1 mem_used {taskname {IP RIB Update} op gt val 50 is_percent TRUE period 60.000 }
action 1.0 syslog msg "IOSWD_Sample3 Policy Triggered"
•For information about EEM overview, go to "Embedded Event Manager Overview" module.
•For information about writing EEM policies using Tcl, go to "Writing Embedded Event Manager Policies Using Tcl" module.
The following sections provide references related to writing EEM policies Using the Cisco IOS XE software CLI.
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No new or modified standards are supported, and support for existing standards has not been modified. |
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CISCO-EMBEDDED-EVENT-MGR-MIB |
To locate and download MIBs for selected platforms, Cisco IOS XE software releases, and feature sets, use Cisco MIB Locator found at the following URL: |
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No new or modified RFCs are supported, and support for existing RFCs has not been modified. |
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Table 3 lists the features in this module and provides links to specific configuration information.
Not all commands may be available in your Cisco IOS XE software release. For release information about a specific command, see the command reference documentation.
Use Cisco Feature Navigator to find information about platform support and software image support. Cisco Feature Navigator enables you to determine which Cisco IOS XE software images support a specific software release, feature set, or platform. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.
Note Table 3 lists only the Cisco IOS XE software release that introduced support for a given feature in a given Cisco IOS XE software release train. Unless noted otherwise, subsequent releases of that Cisco IOS XE software release train also support that feature.
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Embedded Event Manager 1.0 |
Cisco IOS XE Release 2.1 |
EEM 1.0 introduced Embedded Event Manager applet creation with the SNMP and syslog event detectors. EEM 1.0 also introduced the following actions: generating prioritized syslog messages, generating a CNS event for upstream processing by Cisco CNS devices, reloading the Cisco IOS XE software, and switching to a secondary processor in a fully redundant hardware configuration. The following sections provide information about this feature: •Embedded Event Manager Policies •EEM Actions Available by Cisco IOS XE Software Release •Registering and Defining an Embedded Event Manager Applet •Displaying Embedded Event Manager Registered Policies The following commands were introduced by this feature: action cns-event, action force-switchover, action reload, action syslog, debug event manager, event manager applet, event snmp, event syslog, show event manager policy registered. |
Embedded Event Manager 2.0 |
Cisco IOS XE Release 2.1 |
EEM 2.0 introduced the application-specific event detector, the counter event detector, the interface counter event detector, the timer event detector, and the watchdog event detector. New actions included modifying a named counter, publishing an application-specific event, and generating an SNMP trap. The ability to define environment variables and to run EEM policies written using Tcl was introduced, and two sample policies were included with the software. The following sections provide information about this feature: •Embedded Event Manager Policies •EEM Actions Available by Cisco IOS XE Software Release •Registering and Defining an Embedded Event Manager Policy to Run Manually •Unregistering Embedded Event Manager Policies •Suspending Embedded Event Manager Policy Execution •Displaying Embedded Event Manager History Data •Embedded Event Manager Applet Configuration: Examples •Embedded Event Manager Watchdog System Monitor Event Detector Configuration: Example The following commands were introduced by this feature: action counter, action publish-event, action snmp-trap, event application, event counter, event interface, event ioswdsysmon, event manager environment, event manager history size, event manager policy, event manager scheduler suspend, event timer, show event manager environment, show event manager history events, show event manager history traps, show event manager policy available, show event manager policy pending. |
Embedded Event Manager 2.1 |
Cisco IOS XE Release 2.1 |
EEM 2.1 introduced some new event detectors and actions with new functionality to allow EEM policies to be run manually and the ability to run multiple concurrent policies. Support for Simple Network Management Protocol (SNMP) event detector rate-based events was provided as was the ability to create policies using Tool Command Language (Tcl). The following sections provide information about this feature: •Embedded Event Manager Policies •EEM Actions Available by Cisco IOS XE Software Release •Registering and Defining an Embedded Event Manager Policy to Run Manually •Embedded Event Manager Applet Configuration: Examples The following commands were introduced or modified by this feature: action cli, action counter, action info, action mail, action policy, debug event manager, event cli, event manager directory user, event manager policy, event manager run, event manager scheduler script, event manager session cli username, event none, event oir, event snmp, event syslog, set (EEM), show event manager directory user, show event manager policy registered, show event manager session cli username. |
Embedded Event Manager 2.1 (Software Modularity) |
Cisco IOS XE Release 2.1 |
EEM 2.1 for Software Modularity images introduced the GOLD, system manager, and WDSysMon (Cisco IOS XE Software Modularity watchdog) event detectors, and the ability to display Cisco IOS XE software Modularity processes and process metrics. Note GOLD is not supported on the Cisco ASR 1000 Series routers. The following sections provide information about this, feature: •Embedded Event Manager Policies •EEM Actions Available by Cisco IOS XE Software Release •Embedded Event Manager Applet Configuration: Examples The following commands were introduced by this feature: event gold, event process, show event manager metric process. Note EEM 2.1 for Software Modularity images also supports the resource and RF event detectors introduced in EEM 2.2, but it does not support the enhanced object tracking event detector or the actions to read and set tracked objects. |
Embedded Event Manager 2.2 |
Cisco IOS XE Release 2.1 |
EEM 2.2 introduced the enhanced object tracking, resource, and RF event detectors. The actions of reading and setting the state of a tracked object were also introduced. The following sections provide information about this feature: •Embedded Event Manager Policies •EEM Actions Available by Cisco IOS XE Software Release •Configuring and Tracking a Stub Object Using Embedded Event Manager •Configuring and Tracking a Stub Object Using Embedded Event Manager: Example The following commands were introduced or modified by this feature: action track read, action track set, default-state, event resource, event rf, event track, show track, track stub-object. |
SNMP event detector delta environment variable1 |
Cisco IOS XE Release 2.1 |
A new SNMP event detector environment variable, __snmp_old_delta_val, was introduced. |
Embedded Event Manager 2.3 |
Cisco IOS XE Release 2.1 |
EEM 2.3 introduced some new features relative to the Generic Online Diagnostics (GOLD) Event Detector on the Cisco Catalyst 6500 Series switches. Note GOLD is not supported on the Cisco ASR 1000 Series routers. The event gold command was enhanced in addition to the Tcl keywords—action-notify, testing-type, test-name, test-id, consecutive-failure, platform-action, and maxrun—for improved reaction to GOLD test failures and conditions The following section was updated to describe the enhanced functionality of the event gold command: •Embedded Event Manager Built-In Environment Variables Used in EEM Applets Read-only variables were added under the GOLD Event Detector category to provide access to platform-wide and test-specific GOLD event detector information for a detected event. |
1 This is a minor enhancement. Minor enhancements are not typically listed in Feature Navigator. |