DDS — Additional_qos_DATA_PRIORITY Issue

Issue# 2090 Additional_qos_DATA_PRIORITY Issue [Boeing SOSCOE] ? Need for additional DATA_PRIORITY Qos on the DataWriter. This Policy defines a priority that is associated with the data contained in a message and would serve two purposes: • 1) It would provide a prioritization mechanism for the transport, and • 2) It would determine how the receiver queues things in the data reader ? For the SOSCOE application this policy would have to support at least 5 values each with descending priority: (Flash_Override, Flash, Immediate, Priority, Routine) ? Ideally there would be a way to propagate and map this to whatever underlying transport is being used to send the messages. ? In its effect on the queuing on the receiving side it acts as a DESTINATION_ORDER QoS. In effect, the order would be BY_PRIORITY. ? Note that it would be possible to have DESTINATION_ORDER BY_PRIORITY and HISTORY KEEP_LAST. In this case, the reader may throw away the higher priority data if another message arrives. This is OK. If this is not the desired behavior, then the application should specify KEEP_ALL (which is expected to be the normal use in practice). Proposal [Boeing SOSCOE] ? Add a DATA_PRIORITY Qos.

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