C2MS — Mnemonic Value Request comments

(Mnemonic Value Request) Section 7.8.1

• In GMSEC, re-requesting on the same name is (per an e-mail thread with GSFC) defined as replacing the previous subscription instead of being additive/subtractive. Is that notion being kept in this spec? If so, this should be explicitly defined in the specification.
• DURATION: When there is no DURATION specified, but a component decides to have a maximum duration anyway, data will arbitrarily stop. This is problematic for subscriptions by a non-UI system component, like a script that checks telemetry values or a roll-up / derived capability that subscribes to data to produce second-level data. Mechanisms to avoid such stoppages in data, such as periodically resubscribing are wasteful and potentially inconsistent between components.

Part covered by issue 8, DURATION issue to be fixed by adding final message

Rerequesting will be solved by resolution to issue 8, request-id. Duration will be solved by adding paragraph near duration description that final-message flag should always be set on sending final message. At the very end of section 8.8.1.3, where self-imposed duration is discussed, add this: "If a data provider does self-impose a maximum duration, the FINAL-MESSAGE field should be set appropriately in the last message sent."