JMS communication

JMS connection limit

The NFM-P supports a maximum of 10 or 20 concurrent JMS connections, depending on the available system resources. See the NSP Planning Guide for the platform sizing requirements regarding the JMS connection limit.

A JMS connection attempt when the limit is reached generates the following exception:

Exception: XML API Maximum Connected Clients

Nokia recommends that an OSS should use only one JMS connection per JMS topic. When an OSS client needs to receive events from multiple JMS topics, Nokia recommends subscribing to the 5620-SAM-topic-xml-filtered topic, which supports advanced message filtering and allows an OSS to receive any required events. See JMS message filtering for information about advanced message filtering.

JMS filtering

To reduce the JMS event traffic volume, an OSS must use a JMS filter to specify the events that the OSS requires. A JMS filter must allow critical system events to pass. When an OSS client subscribes to the 5620-SAM-topic-xml-filtered topic, the client can use an advanced message filter to specify event messages. See JMS message filtering for information about advanced message filtering.

Monitoring a JMS connection

To ensure that the JMS connection is active, all incoming events including the following events must be monitored:

KeepAliveEvent
TerminateClientSessionEvent
StateChangeEvent (JMSMissedEvent and SystemInfoEvent)

If no events are received for two minutes, the status of the NFM-P server must be checked.

See Connection monitoring and error recovery for more information.

JMS acknowledgment mode

The NFM-P supports the following acknowledgment modes:

AUTO_ACKNOWLEDGE
DUPS_OK_ACKNOWLEDGE

Nokia recommends that OSS clients use DUPS_OK_ACKNOWLEDGE mode in a network environment with high latency to improve JMS message throughput. OSS clients using this mode must be able to handle the potential of duplicate JMS messages. See Connection monitoring and error recovery for more information.

Use the 5620-SAM-topic-xml-filtered JMS topic

Nokia recommends that OSS clients use the 5620-SAM-topic-xml-filtered topic for the following benefit:

The advance message filter selects messages using the JMS header field as well as the message body and object properties.
The result filter selects only the required attributes to be sent to OSS clients.
OSS clients can adjust the advance JMS filter dynamically without disconnecting the JMS connection.
Multiple events are sent using the event vessel message to enhance events delivery throughput.

Advanced message filtering

The JMS 5620-SAM-topic-xml-filtered topic supports advanced message filtering. Nokia recommends the following:

In the advanced message filter, the “classname” should be included in the extra tag to facilitate processing of attribute value change events.
Because message filter elements are limited, consider the “in” filter element to eliminate the need for using logical “or” with numerous leaf filter elements.