Microsoft Message Queuing (MSMQ)

Microsoft Message Queuing (MSMQ) is a Windows component developed by Microsoft that is used for sending notification messages. For more information about MSMQ, see http://msdn.microsoft.com/en-us/library/ms711472(v=VS.85).aspx.

As of PCo 2.3, MSMQ is used for sending notification messages within the notification process. If you install PCo 2.3, the Windows component MSMQ is installed automatically. For more information about installing MSMQ, see the installation guide for PCo 2.3 on the SAP Help Portal page for SAP Plant Connectivity under https://help.sap.com/pco.

For each agent instance, individual queues are used for sending notification messages. The queues are set up automatically as soon as you start an agent instance. The following queues are created:

Main queue
Queue for failed messages
Queue for expired messages
Queue for messages that are waiting to be bundled
Queue for messages that are part of another message

The queues for an agent instance are removed again when you delete the agent instance.

Caution Caution

Note that MSMQ queues have a size restriction for messages. The maximum size of messages is 4 MB. If, via PCo, you place a larger message in the queue, you get an error message in the PCo log that refers to insufficient resources.

End of the caution.

You make the settings for sending notification messages on the Host tab for the agent instance. (See Settings for the Notification Message Queue.)

You can find the content of the queues, for example, in Windows 7 under Start of the navigation path Control Panel Next navigation step Administrative Tools Computer Management Services and Applications Message Queuing System Queues End of the navigation path . In this view, you can also analyze messages and remove them from the queues if necessary.