PATROL  events

This topic provides information on PATROL events.

• • About the PATROL Event Manager (PEM)
  • About the PATROL API
  • About PATROL event catalogs
  • About event classes
  • Event class commands
  • How PATROL events are triggered
  • How PATROL processes an event
  • About messages and event classes

Inside the PATROL product, an event is any kind of asynchronous information generated by the PATROL Agent. An event is created when any monitored object changes state or the PATROL Agent detects any condition that is noteworthy or an event is explicitly generated by a PSL script. In addition such actions as a PATROL Console connecting to the PATROL Agent or a PSL task executing are considered events. Many things can generate an event.

Events can be generated by the PATROL Agent, a PATROL Knowledge Module, another remote agent, or any application that uses the PATROL API.

Using criteria from both the Standard Event Catalog and from PATROL KM event catalogs, the PATROL Agent processes an event as part of monitoring and stores the event in an event repository. If the PATROL Agent is connected to the PATROL Event Manager, the PATROL Agent forwards the event to the PATROL Event Manager. The types of events forwarded by the PATROL Agent are controlled by a persistent filter set for each Event Manager/ PATROL Agent relationship.

Multiple consoles can share the same events, and an action applied to a given event is seen by other consoles monitoring the same PATROL Agent. For example, if two users are viewing the event log for the same host and one user acknowledges the event, this action appears in the both console windows.

An event belongs to a particular event class which defines properties that the event has and how the event is to be processed by the PATROL Event Manager. Event classes are defined in the PATROL Standard Event Catalog or in KM-specific (application class) event catalogs.

About the PATROL Event Manager (PEM)

The PATROL Event Manager (PEM) is a core component of the PATROL Agent architecture, providing agent level event management. The PEM engine manages events originating from the PATROL Agent, PATROL Knowledge Modules running on the PATROL Agent, or any event generating application that is connected to the PATROL Agent through the PATROL Cli or PEM API. The PATROL product offers various methods of accessing PEM data including through the PATROL Script Language (PSL) and through the PATROL API.

About the PATROL API

The PATROL API allows external components and user-written (non-PATROL) applications to interface with the PEM and perform actions including:

• Generating an event
• Closing, acknowledging, or deleting an event
• Escalating an event to higher-level of visibility
• Performing event queries

The PATROL API supports both advanced event-driven application management within PATROL KMs and event integration to third-party management frameworks. Each connection to the PATROL Agent has its own handle so the PATROL API can allow a non-PATROL program to connect to any number of PATROL Agents either on a single host or on multiple hosts. The network transport layer used by the PATROL API is compatible with UDP and TCP.

About PATROL event catalogs

You create events classes in event catalogs. The PATROL product has two types of event catalogs--the Standard Event Catalog and application class event catalogs. The following table summarizes the PATROL event catalog types.

PATROL standard event catalog

The PATROL Standard Event Catalog is the repository for the event class definitions that are available to the core PATROL product. It is a file named StdEvent.ctg that resides in a specific directory on each platform that PATROL supports: 

%PATROL_HOME%\lib\knowledge (Windows) 

$PATROL_HOME/lib/knowledge (UNIX)

Application event catalog

A PATROL application event catalog contains the event classes that used by a particular PATROL application class. You create an application event catalog in the Event Catalog folder for the application class.

About event classes

An event class is a class definition that describes the properties that an event of that class can have and how it is to be processed by the PATROL Event Manager. 

Each event class has the following properties:

• General properties such as name, event type and category
• Escalation command and its properties
• Notification command and its properties
• Acknowledge command and its properties
• Expert Advice
• Description

The following table summarizes event class properties:

PATROL event types

A PATROL event type is the category of an event as defined by its event class. It is used primarily as a sorting filter in the PATROL Event Manager display. You can assign a PATROL event to one of the following event types:

Object versus the STATE_CHANGE action

Object action events are defined as the Standard Event Catalog Event types that have a Message Type of WARN, ALARM, or INFO and include description text of the format: 

"STATE_CHANGE:" <old> <new> 

where the value of <old> is the original object state and the value of <new> is the current object state. 

These object action events should not be confused with the STATE_CHANGE event which does not include the word STATE_CHANGE in its description.

Event class commands

Each PATROL event class can have the following event commands defined:

You can define a generic message in the event class description for an event class. Using the event-related PATROL built-in variables, you can build a generic event class description that gives the user the critical information about the event. The description will appear in a PEM console.

How PATROL events are triggered

PATROL events are triggered automatically whenever an state change occurs. PATROL events also can be triggered explicitly by the PSL event_trigger() and event_trigger2() functions. These functions allow you to trigger an event of a specific event class, assign a severity to it, and perform event-driven processing through the event Notification command.

 Event severity

Although severity is not an event class property, an event instance can have a severity value to indicate how serious the event is. Event severity can be assigned to an event through the PSL event_trigger() and event_trigger2() functions. Event severity can be an integer value between 1 and 5, with a value of 5 indicating the most serious events. Event severity is used as a filter to limit the events that display in an event management console to only those of equal or greater severity than the specified filter.

How PATROL processes an event

The following figure shows how the PATROL Agent processes a PATROL event and its associated commands. On detecting a condition, the PATROL Agent starts an event timer and schedules execution of any commands associated with the event's event type. If a notification command is defined, it is executed immediately after the event occurs. You can create notification commands to do the following things:

• Send messages
• Take corrective actions

Next, if the escalation period lapses without being acknowledged, the PATROL Agent does the following things:

• Changes the event's status to escalated
• Adds an entry to the PEM event diary, if a PEM console is connected
• Executes the escalation command, if one is defined for the event class. An escalation command is used to escalate an event's visibility.

Finally, if an acknowledgment command is defined for the event class, it is executed only when the event is acknowledged by a user through a PEM console. An acknowledgment command can be used to silence alarms. 

The only way that an event can cause action is through its Escalation, Notification and Acknowledge commands specified in the event's class definition. 

Event processing logic 

About messages and event classes

As described in the following table, event classes have three built-in features that allow you to propagate information about an event to users: