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The uPortal software maintains a number of statistics as managed beans (MBeans) in the Java Virtual Machine (JVM). A Java Management Extension (JMX) client, such as Jmxterm, can be used to retrieve those statistics such that they can be made available to an external monitoring system. This document shows Cacti (open source - http://www.cacti.net/) as a monitoring system, which is great at archiving this kind of data and displaying it as a collection of versatile graphs. The same approach can be used to feed a monitoring system such as Spectrum (commercial - http://www.ca.com/). Spectrum's strength is that you can setup thresholds that throw alerts when those thresholds are exceeded.
Note: This documentation is rather UNIX/Linux specific.
Opening JMX up on the JVM
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Once everything is implemented, your SNMP-based monitoring system can start to produce results like these:
MBean Attribute: UserSessionCount
SNMP OID: .1.3.6.1.4.1.32396.1.3.205
MBean Attribute: AuthenticationAverage
SNMP OID: .1.3.6.1.4.1.32396.1.3.200
MBean Attribute: DatabaseLast
SNMP OID: .1.3.6.1.4.1.32396.1.3.201
MBean Attribute: Not Applicable, File Descriptors are collected in a script via this command: /usr/sbin/lsof -u "tomcat" | wc -l
SNMP OID: .1.3.6.1.4.1.32396.1.3.202
MBean Attribute: RenderAverage
SNMP OID: .1.3.6.1.4.1.32396.1.3.203