#967 IMM: Document non persistence of system attribue SaImmAttrImplementerName

[Anders Bjornerstedt]

Ticket #543 fixed a problem with incomplete (lazy) persistence for the
system attribute SaImmAttrImplementerName. The fix was to make this attribute
non persistent. Similarly to the attribute SaImmAttrAdminOwnerName, the value
is dumped to file when an immdump is requested. This is mainly to assist
debugging/verification of behavior. But the value is discarded at loading.

This change in behavior introduced in 4.3 was not strictly backwards compatible.
Some applications may have relied on the incomplete persistence of the
SaImmAttrImplementerName attribute.

But the alternative of making the attribute fully persistent is both complex
and costly in performance. At the same time the only value of such added
complexity would be worth very little. The only effect is that some rare
applicaitons may avoid invoking saImmOIObjectImplementerSet after a cluster
restart.

But that feature does not apply to the normally used saImmOiClassImplementerSet
and its reliance by users of SAImmObjectImplementerSet is unsafe, even
prior to the fix of #543. Instead applications should simplify hteir code and
always invoke this call after a restart, relying on its idempotency.

But the persistence behavior of this attribute needs to be documented in
the non-compliance section of the OpenSAF_IMMSv_PR.
The SAF IMM spec actually is inconsistent (non backwards compatible)
on this issue between A.2.1 and A.3.1. And so it is not a pure non-compliance
issue.

[Anders Bjornerstedt]

http://sourceforge.net/p/opensaf/mailman/opensaf-devel/thread/patchbomb.1408525076%40sekic2756.rnd.ki.sw.ericsson.se/#msg32738814

[Anders Bjornerstedt]

Will push this at the end of this week if there are no objections.

[Anders Bjornerstedt]

changeset: 5686:43929f460018
tag: tip
parent: 5682:5a99a83844d9
user: Anders Bjornerstedt anders.bjornerstedt@ericsson.com
date: Wed Aug 20 10:48:41 2014 +0200
summary: IMM: Document persistence behavior for system attribues [#967]

changeset: 5685:aec0afeb53a6
branch: opensaf-4.5.x
parent: 5681:879f48c46b42
user: Anders Bjornerstedt anders.bjornerstedt@ericsson.com
date: Wed Aug 20 10:48:41 2014 +0200
summary: IMM: Document persistence behavior for system attribues [#967]

changeset: 5684:b0c718e66134
branch: opensaf-4.4.x
parent: 5680:c349554571e0
user: Anders Bjornerstedt anders.bjornerstedt@ericsson.com
date: Wed Aug 20 10:48:41 2014 +0200
summary: IMM: Document persistence behavior for system attribues [#967]

changeset: 5683:e32f693704a4
branch: opensaf-4.3.x
parent: 5679:41f97af6d5b7
user: Anders Bjornerstedt anders.bjornerstedt@ericsson.com
date: Wed Aug 20 10:48:41 2014 +0200
summary: IMM: Document persistence behavior for system attribues [#967]