Topo Notification Filter: Overview
Topo Notification Filter is used to filter the notifications received from TopoObservers and to notify only for a specific managed object criteria. To make use of this feature
This example illustrates the implementation of Topo Notification Filter. Invoking this example would display the discovery status for all the networks in stdout.txt file in <Web NMS Home>/logs directory or in the command prompt. The discovery status indicates whether the discovery for a particular network is yet to be started, started or completed. This is done by writing an XML file (FilterXml.conf) and a user class (NetDiscoveryStatusListener) which implements the TopoNotificationHandler interface. The user class gets invoked, when the properties specified in the XML file matches with the discovered managed object properties.
The XML file includes the following criteria:
XML File Description
|APPLN_NAME||The name given to the XML tree application, which contains the match criteria.|
|NOTIFICATION||Represents the type (add, delete, update, status, managed, properties, etc.). In this example, the type is specified as ADDED and the Property as STATUS, which indicates that the notification should be sent only when a managed object is added and for a specific property change.|
|MO_PROP_TEST||Represents the managed object properties, viz., name, isNode, discoverystatus, and the corresponding values for which the notification is to be sent.|
|USERCLASS||Represents the user class, which gets invoked when the criteria specified in the XML file matches with that of the incoming managed object.|
|MO_PROPS||The list of managed object properties which can be specified, to get the values at runtime. These properties are used in the user class to test for the specific criteria based on the change in the values (made at run time)|
|ARGUMENTS||The required arguments to be passed to the user class.|
|CRITERIA||The criteria can be specified as AND or OR. Based on this criteria,
the arguments are taken. For e.g. if two arguments are specified and both
the criteria have to be considered for filtering the notification, AND
is given as the value for CRITERIA. On the other hand if it is sufficient
that one argument can be considered, OR is given as the value for the CRITERIA.
In the above XML file, the criteria value is given as AND, hence Notification is sent only when the discovered object is a node and for all status of discovery.
Brief Note on the Files Bundled with this Example
You can either modify the source code of NetDiscoveryStatusListener.java or write your own user class to suit specific requirements. Please follow the steps given below, to integrate this example with Web NMS.
Classpath SettingsNote : To uninstall this example from Web NMS, comment the entries specified in NmsProcessesBE.conf file.
Set classpath=.;<Web NMS Home>\classes;
<Web NMS Home>\classes\xalan.jar;
<Web NMS Home>\classes\AdventNetSnmp.jar;
<Web NMS Home>\AdventNetSNMPv3\classes
Compiling the Example
Invoke the batch file compileTopoNotificationExample.bat/.sh to compile the java files NetDiscoveryStatusListener.java and NetDiscoveryStatusHandler.java
Invoking the Example
You can invoke this example using the TopoNotificationRegistryIfc interface or using Topo API reference.
Invoking using TopoNotificationRegistryIfc interface - Before invoking this example using TopoNotificationRegistryIfc interface from same or different JVM, uncomment the following entries in NmsProcessesBE.conf file.
From same JVM - To invoke or execute this example using TopoNotificationRegistryIfc interface from same JVM, include the following entry in
NmsProcessesBE.conf file and execute the startTopoNotificationExample.bat/.sh file in <Web NMS Home>/examples/topo_notification_registry directory.
From different JVM - To invoke this example using TopoNotificationRegistryIfc interface from different JVM, execute the
startTopoNotificationExample.bat/.sh file in <Web NMS Home>/examples/topo_notification_registry directory.
Invoking using TopoAPI - To invoke this example using TopoAPI, comment the following entry in NmsProcessesBE.conf file and execute the startTopoNotificationExample.bat/.sh file in <Web NMS Home>/examples/topo_notification_registry directory.