Controlling Number of Concurrent Sessions

You can control the number of concurrent listeners and senders using Configurator.

There are several reasons why you might change defaults:

  • When TIBCO MDM starts, it establishes connections for each listener. If there are a large number of queues and listeners, it may take some time to complete the startup. Similarly, when the application shuts down, it closes all connections. Closing of connections can take a long time. To minimize this shut down time, select these values appropriately.
  • You can control the number of listeners to control the CPU load. When all listeners, especially the workflow and Async process listeners, are running, TIBCO MDM CPU usage goes up. If you want to reduce the CPU usage, you can reduce the maximum number of such listeners.
  • By setting the number of listeners to 0, the processing of messages on a specific queue is disabled for a TIBCO MDM instance. This may be used to segment workload between various instances. For example, by setting the workflow listener count to 0, no workflows are processed on a TIBCO MDM instance, which may be dedicated to support incoming webservices or UI.

The number of listeners for each configuration is controlled by the pool size defined for each receiver manager. Defaults sizes are recommended settings for a medium-sized TIBCO MDM installation.

Similarly, the number of senders is controlled by the pool size defined for each sender manager. Typically, the count of senders is smaller than the count of receivers.

Pool size for receiver and sender managers can be set using the Configurator. These are available at the instance level under the categories Async Task Management, Integration Setup - External, and Integration Setup - Internal.

  • Too high a pool size will create too many threads and may use lot of heap to generate an out of memory error.
  • Too low pool size will reduce the throughput. In general, pool size of higher than eight should be used with caution.

For example: Member1 > Async Task Management > Async Queue Receiver Pool Size.

Note: A higher number of queue listeners increases the startup and shutdown time for TIBCO MDM, especially when Websphere MQ is used as the JMS Server. Adjust the pool sizes for your installation to achieve optimal balance between performance and startup times. Higher pool sizes may also require a large channel count (MAXCHANNELS and MAXACTIVECHANNELS parameters of the qm.ini file).

You can re-configure the listeners and sender without restarting the server. The reconfiguration is done using JMX controls provided. See TIBCO MDM Monitoring and Management Using JMX for more details.