Appendix H: High Performance Data Export Framework (HPDEF) tuning

The system processes a large amount of data and stores it in the High Performance Data Export Framework (HPDEF) queues. In large systems, the queues may not have enough space to accommodate all the data. In those instances, the system displays the following error message in the oaserrlog.log file:

ERROR - Timed out trying to lock DataExport.<queue_name>

Where:

• <queue_name> is the name of the queue that must be increased.

For information on how to override the default size of the HPDEF queues, see the AVEVA Enterprise SCADA RealTime Developer documentation.

There is no fixed rule for how to calculate the size of the queue because many factors are involved. As a starting point, the size could be the size of a message in kilobyte (KB) multiplied by the expected peak arrival rate of messages.

Queue size = Message Size KB x Peak arrival rate

The message size is twice that of the RealTime table's record size. The table name and the queue name will be the same.

Example:

Analog table record size = 4 KB

Message size = 4 x 2 = 8 KB

Peak arrival rate = 10000 messages / sec

Analog Queue size = 8 x 10000 = 80000

Note: The maximum queue size is 4000000 and cannot be changed.