[zeromq-dev] thoughts on pub-sub messaging and "reliability"

[Holger Joukl]

> Von: Dorvin
> W dniu 2014-10-20 09:21, Holger Joukl pisze:
>
> > As always, it's a tradeoff you have to make: Higher "QoS" usually
> > means lesser throughput, much like memory vs speed tradeoffs.
>
> Side note: Please don't confuse "reliability" and "QoS". QoS has nothing
> to do with reliability. It's for prioritizing some traffic classes and
> rate-limiting others in case of congestion. Knowing the difference might
> save you a lot of time when talking to networking guys while
> troubleshooting reliability issue. :)

Thanks for the hint.

Sadly and as often the case this term is used with multiple meanings
in different contexts, see e.g. the QoS definitions of the MQTT protocol:
http://public.dhe.ibm.com/software/dw/webservices/ws-mqtt/MQTT_V3.1_Protocol_Specific.pdf

I don't know where the term first originated from but I agree
it's best to avoid confusion. So maybe "delivery guarantees" or
"reliability level" might be better words.

Best regards
Holger

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