DDSXTY12 — Topic incosisstency only considered for incompatible types, not for incompatible qos

What if 2 topics have the same type, but different Qos? Would that still trigger an INCONSISTENT_TOPIC status or not? The spec does not say anything about this.

Discussed clarifications

The TF discussed clarifications and no changes are needed.

Currently, the spec is clear about when inconsistent_topic status is raised. Only type (typeobject when present otherwise typename) is considered before raising the inconsistent topic status. One possibility to incorporate QoS in the mix would be to create yet another kind of status for topics. Right now it has only one. For DR and DW, there’s already inconsistent_requested_qos and inconsistent_offer_qos statuses. May be the new status could be a variant of those. It can’t be any of those however because (1) TopicQoS does not contain all QoS (2) TopicListener is a separate inheritance branch and (3) offered/requested semantics are not knowable at topic level because we don’t know what kind of entity might be created (so we can’t do as good a job as we do for entity’s inconsistent_requested/offered_qos statuses.)