Managing NerveCenter
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Understanding NerveCenter - How NerveCenter Manages Nodes - Responding to Conditions -
NerveCenter not only enables you to detect network and system problems, but is able to respond automatically to the conditions it detects. To set up these automated responses, you associate actions with state transitions.
The possible actions you can define are discussed in the following sections:
If a particular network or system condition requires the attention of an administrator, the best action to take in response to that condition is to notify the appropriate person. NerveCenter lets you notify administrators of events in the following ways:
For more information on integrating NerveCenter with other network management products, see the section Role in Network Management Strategy.
If you want to keep a record of an event that takes place on your network, you must explicitly log information about the event at the time it occurs. NerveCenter provides three actions that provide for such logging:
Log to File writes information about an event to a file. Log to Database writes information about an event to the NerveCenter database. The EventLog action writes information about an event to an event or system log.
When you assign a logging action to a behavior model, you have the choice of logging default data or customizing what data you deem relevant. This saves disk space and streamlines information used later for analysis and reporting.
In some behavior models, one alarm needs to cause a transition in another. The action that enables such communication between alarms is called Fire Trigger. This action creates a NerveCenter object called a trigger that can cause a state transition in the alarm from which it was fired or in another alarm.
The Fire Trigger action also lets you specify a delay, so you can request that a trigger be fired in one minute or five hours. This feature is especially useful when you're looking for the persistence of a condition. Let's say that you want to look for three intervals of high traffic on an interface within a two-minute period. When your poll detects the first instance of high traffic, and your alarm moves out of the Ground state, you can fire a trigger with a two-minute delay that will return your alarm to the Ground state -- unless a second and third instance of high traffic are detected.
If a third instance of high traffic is detected, you should cancel the trigger you fired on a delayed basis. You do this by adding the Clear Trigger action to the transition from the second high-traffic state to the third.
NerveCenter also includes a Send Trap action. You define the trap to be sent, including the variable bindings, and associate the action with a state transition. When the transition occurs, the trap is sent. The trap can be caught by a NerveCenter trap mask -- in which case you can use Send Trap somewhat like Fire Trigger, to generate a trigger -- or by any application that processes SNMP traps.
There are a number of NerveCenter actions that you can use to take corrective actions when a particular state transition occurs. These are:
The Command action enables you to run any script or executable when a particular transition occurs.
The Perl Subroutine action enables you to execute a Perl script as a state-transition action. You first define a collection of Perl scripts and store them in the NerveCenter database; then, you choose one of your stored scripts for execution during a state transition.
The Set Attribute action enables you to set selected attributes of the NerveCenter objects used to build behavior models.
The Delete Node action deletes the node associated with the current state machine from the NerveCenter database. This action is useful if you use a behavior model to determine which nodes you want to monitor and manage.
The SNMP Set alarm action changes the value of a MIB attribute when an alarm transition occurs.
The Action Router enables you to specify actions that should be performed when a state transition occurs and other conditions are met. To set up these conditional actions, you add the Action Router action to your state transition. Then, you use the Action Router tool to define rules and their associated actions.
For example, let's assume that you want to be notified about a state transition only if the transition puts the alarm in a critical state. You can define the following rule:
$DestStateSev eq `Critical'
Then define the action you want taken if the severity of the destination state is Critical, for example, a page. You will be paged if:
Action Router rules can be constructed using many variables that NerveCenter maintains; for instance, you can also construct rules based on:
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| Please send comments or corrections to Information Development | This file was last updated on 10 October 2000 |