RE: [ebxml-msg] end-to-end RM option in case of WS-ReliableMessaging

["Pim van der Eijk" <pvde@sonnenglanz.net>]

 

In order of priority, I think that the main elements that routing applications would want to use for routing decisions are:

- To/PartyId (for

- To/PartyId/@type 

- Service (for SOA-style messaging)

- Action

- ConversationId (for ebMS business session affinity)

- MessageProperties (e.g. "indicatorMessageIsATestMessage")

 

I.e. routing based on user message elements rather than signal message "mpc" elements, as implemented by multiple ebMS2 products and used in some ebMS2 deployments today. 

 

I assume you are suggesting bundling with an ebMS signal to avoid having to send a User Message bundled with an (unreliable) sequence creation message. But perhaps we can require some special ebMS processing support for this particular User Message, e.g. some way of requiring an eb:Receipt at the ebMS level binding? 

 

(This might also require an ebMS-level retry, if just for this sequence creation piggy back message case; and this might also require a different eb:MessageId, in order to avoid duplicate elimination at the WS-R/WS-RM level).  Or perhaps we should extend the Signal Message with elements from the User Message (optional to remain compatible with Part 1).

 

If the only parameter available for routing is an mpc name string, the first thing I would put in those mpc names would be concatenations of PartyId, Service etc. which to me shows we are missing some generalization here ...  

 

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From: Durand, Jacques R. [mailto:JDurand@us.fujitsu.com]
Sent: 12 December 2007 21:59
To: ebxml-msg@lists.oasis-open.org
Subject: [ebxml-msg] end-to-end RM option in case of WS-ReliableMessaging

Following the end-to-end RM option for a Push mep in case of WS-ReliableMessaging:

 

 

Assumptions: (actually needed whenever RM sequences are used, regardless of which reliability specification)

 

- the sender always knows which messages are for the same destination, even if the decision about what this destination is (URL) is left to the routing function. A destination is also supposed to map to a single RM destination (i.e. there are not two RM Destination modules serving the same business destination)

- the sender knows what fileds in a message are used to resolve the routing path, so that a dummy ebMS [user] message can be crafted to establish the RM sequence prior to sending actual user messages. Recommendation is: to simply use MPCs as routing means.

 

Features:

 

Piggybacking of an ebMS "dummy"  message on all RM sequence management messages.

No new ebMS signal needs be designed for this piggybacking : a "dummy"  user message has the service field set to: http://docs.oasis-open.org/ebxml-msg/ebms/v3.0/ns/core/200704/service

which is enough to process it correctly in core V3, i.e. to NOT deliver it to the MSH consumer layer. (that way, no additional feature is required from the destination MSH, other than core V3 compliance). We might want to specify a new Action field value, but no need to interpret it on receiver side.

 

- teh response RM management messages need be routed back. Suggest to put the burden of the piggybacking for these responses on the last MSH intermediary, not on the ultimate MSH who should not be aware of the RM-thru-intermediaries aspects.

 

 

Comments: all this is about using ebMS intermediaries. Clearly, alternative forms of multi-hop routing can apply to achieve end-to-end reliable exchanges, such as SOAP intermediaries (non-MSH) that use WS-addressing wsa:To, wsa;From or wsa:Action headers.  Both styles can co-exist: such SOAP nodes could be intertwined with MSH intermediaries on a path. We do not specify that one. In that case, different nodes on a path will use different routing info (e.g. wsa header vs. ebMS header).

 

Jacques