Summary of the MSH Default
Operating Mode (DOM) feature, as previously discussed:
-
DOM is not intended to
represent a default CPA (as defined in CPPA), rather a default operating mode.
-
The main driver for this
feature, is the possibility to deploy and interoperate without any form of prior
CPA negotiation. Note that it may not be possible to use it in some
environments that are incompatible with the DOM (e.g. security-constrained).
-
The value is some easier,
phased testing and deployment.
-
It is not intended as a
normal operating mode for conducting business.
-
A conforming MSH would be
required to implement it, but the feature can be disabled once A deployment is
complete, e.g. for security reasons.
Two options:
(i) DOM is Restricted to a
"CPA-free" ping feature. Useful when undergoing the initial steps of
a deployment, where interoperability has to be established step by step.
(ii) DOM may apply to any
message. Messages can be sent and delivered to applications in that mode, for
end-to-end processing and interop testing.
I suggest that (ii) is more
useful, meaning that the DOM is not restricted to
/ Pong messages, but can be used for initial end-to-end testing, in real
operating context.
- The DOM would be activated
by agreementRef, e.g. with value "eb:default" (or approaching URI).
- It would use no
reliability, no security.
Issues:
- Messages under DOM can be
pushed, but can they be pulled as well? (some MSH may only be intended to
pull.) If yes the pulled message can have been submitted under DOM as well.
This means we assume that the feature that controls whether a submitted message
is queued (for subsequent pulling) or pushed, can be controlled independently
from a CPA (implementation level).
- Some environments may
prohibit the use of DOM, e.g. if they always require some form of security. In
such cases, proper notification must be sent back. This is a more general
issue: discrepancy between what the message header is indicating, and what the
MSH (meaning also the security component) is set to process (per CPA
requirement or other).