I could not find an SLD forum so this place seems as good as any.
An ABAP system has RFC's defined in each system and this has never been an issue.
Now we have J2EE's with adaptive RFC's defined in the SLD rather than in the local system. These 'SM59' style connections are not transferrable between systems as far as I can see and have little value in the SLD as opposed to the local system.
What I see most crazy of all is that after 2 hours these entries are deleted from the local cache and then fetched again fom the SLD. Surely if the fetch fails they should keep using the cached version?
It seems mad to me that they are stored in the SLD and that they time out before they are re-fetched therefore creating significant risk to productive system availability.
I now recommend that Portals have a local SLD that is never patched and have manually defined adaptive RFC connections. The SLD Provider service reads and writes to itself but bridges to a central SLD. These never seem to have issues and now no longer go down due to reliance on that SLD system and network between.
I am very well versed in the SLD and would appreciate responses from people who can correct me in my ways as SAP seems to require me to have a central SLD for these even though I have no maintenance and the GUIDs are not required elsewhere.