Configuring SNMP

As I implied earlier, loading WebLogic is a two-stage process. First, you must obtain an SNMP server and load the WebLogic SNMP MIB into the SNMP manager. The WebLogic SNMP MIB is included with the distribution. It can be found in:

 /classes/weblogic/management/snmp/mib 

It is packaged in the weblogic.jar java archive; the actual file is named BEA-WEBLOGIC-MIB.asn1 . Configuring the SNMP manager is outside the scope of this book, but you have my sincere best wishes.

SNMP configuration is done from the Administration console. There are two steps:

  • Authorize the SNMP manager to which you will direct the traps.

  • Enable the SNMP agent.

  • Configure any agents for whom the server will be proxying.

  • Optionally, configure any additional traps you may wish to install.

Authorize an SNMP Manager

Authorizing an SNMP manager is, of course, done through the Admininstration console. Expand the SNMP folder and click on the Trap Destinations subfolder. There are four fields to fill out:

Name

The name of the SNMP manager to which you will be sending the communications.

Community

The name by which your SNMP manager software refers to the collection of entities being monitored in your WebLogic server domain. This name will be used by the SNMP manager in requesting information from the agent. Requests for information about a particular Managed server will take the form:

community@server

Requests about the Administration server will be directed simply to:

community

Host

The network host upon which the SNMP server is running.

Port

The port over which SNMP communication occurs.

Enable the SNMP Agent

To configure an SNMP agent, click on the SNMP folder in the left pane. Check the Enabled box to activate SNP monitoring. You will need to fill out the following fields:

SNMP Port

The network port over which communication will occur.

MIB Data Refresh Interval

The number of seconds that will elapse before the SNMP agent will update the values that it is monitoring.

Server Status Check Interval Factor

This number will be multipled times the value entered in MIB Data Refresh Interval to arrive at an interval for polling WebLogic Managed servers.

Community

The password for the SNMP community. This password must also be configured on the SNMP server. It will be sent to the agent each time an update is requested .

When configuring the intervals at which SNMP does checks, bear in mind that the level of network traffic generated can be nontrivial.

Proxies

As originally conceived, the SNMP model provided for only a single agent to monitor all activity on a particular IP address. In practice, this idea turned out to be rather limiting. Consequently, WebLogic SNMP incorporates the idea of proxies. A proxy is an SNMP agent that has been configured to act as a collection point for SNMP information about a particular domain.

In the case where multiple servers are being monitored in a single domain, the preferred configuration is to configure the Administration server's SNMP agent as the nexus of communication between the SNMP manager and all other agents in the WebLogic domain.

This is accomplished as follows : Under the SNMP folder in the Administration pane, click on the Proxies folder. There are five fields to fill out:

Name

The name of the resource (typically a server) for which the admin server is serving as a proxy.

Port

The network port over which SNMP communication should occur. Note that this value must be unique; in particular, it should not be the same as the port of the administration console.

OID Root

The MIB number that designates the top of the OID tree under which the resource is proxied .

Community

The name of the community of which the resource is a member, as understood by the SNMP manager.

Timeout

The number of seconds that must elapse before the resource will be considered to have failed.

Monitors

Three types of Java Management Extension (JMX) monitors are available:

Gauge Monitors

Use a gauge monitor to define an upper and lower threshold for the resource being monitored. Alarms will sound if either threshold is exceeded.

String Monitors

String monitors compare the resource being monitored against a text string that you provide.

Counter Monitors

A counter monitor is triggered when the monitored resource exceeds the upper limit of a threshold value.

Log Filters

All WebLogic serversboth administration and managedlog information about server performance and events into files on their respective local machines. SNMP can monitor these log files and alert if it sees particular text strings.

The configuration of these traps is done in the Log Filters folder under SNMP. Most of the configuration values are pretty obvious. Specify the text string that you want to alert on in the "Message Substring" field.

Attribute Changes

Finally, it is also possible to configure SNMP to take note when a configuration attribute changes. Under the Attribute Changes menu, click the "Configure a New Attribute Change" link. There are five fields:

Name

The name of the attribute filter.

Attribute MBean Type

The type of the MBean you want to monitor.

Attribute MBean Name

The name of the MBean that contains the attribute you wish to monitor.

Enabled Servers

Click on the SNMP-enabled WebLogic servers that you want to monitor for this change.

Note also that before the new attribute monitoring will go into effect, you need to restart the Administration server.



BEA WebLogic Server Administration Kit
BEA WebLogic Server Administration Kit (Prentice Hall PTR Advanced Web Development)
ISBN: 0130463868
EAN: 2147483647
Year: 2002
Pages: 134
Authors: Scott Hawkins

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