About QoS of Images

[gbiggs]

@fmrico

Finally, I would like to know why (I am sure there should be a technical reason) a subscriber has his own QoS, instead of automatically using the quality of service of the publisher (with warnings if there is more than one publisher with a different QoS). I think this can make life more pleasant for us.

Although there is no technical reason why subscribers can’t automatically detect and adapt to publishers, there are two reasons they do not:

1. If there is more than one publisher on the topic with different QoS settings, the client library would have to either choose one and risk being incompatible with the other, or somehow mash the two sets of settings together to produce a single superset.
2. Subscribers are their own entity and know best what their own requirements and resources are. They need to set their own QoS properties appropriately.

@BrettRD

The QoS of the subscription functions as a minimum requirement, and the system defaults are needlessly strict.

Can you be more specific about where they are too strict for you?