Welcome back at the SAP on IBM i update! Also in 2012 I want to continue with this series and invite you to participate in the news from our development team.
A disappearing executable
Having installed a 7.20 kernel you will sooner or later realize that programs rfcexec and startrfc are no longer part of the kernel shipment as some of your processes might depend on their existence. You will search for Note 1581595 - rfcexec and startrfc missing after upgrade, which gives general instructions for how to repair the situation on the one hand but also offers a perfect chance to get lost and confused within the world of SAP notes when going after some referenced details.
Don't get me wrong: Most of the reference notes were created on a fair reason and are helpful to find solutions in a variety of situations. And the notes were improved according to recent feedback as well. My hope is simply that a high level overview of the available RFC options could be helpful when you walk through the notes to collect all the steps for fixing the above problem.
So let's get started with the very basics: SAP ships different versions of RFC packages. The old stuff, named Classic RFC or SAP RFC SDK is still in use at many places but not favored by SAP anymore. The currently favored package is called SAP NetWeaver RFC SDK, dubbed nwrfcsdk in many cases. It has been shipped since 2007 to my knowledge. Note 1005832 - Overview on RFC Libraries and SDKs gives an overview of what the single versions are good for.
Classic RFC: SAP RFC SDK
This is definitely not what you need to fix the above scenario. But you should make sure you understand if some note you find is dealing with this version.
Independently of the platform, Note 413708 - Current RFC library tells you which version to use in which OS release and context and where to find it on the Service Marketplace. For IBM i you would go after Note 84685 - AS/400: Availability of RFC in 4.x, 6.x and 7.00 to detect the latest versions and follow instructions of Note 450870 - AS/400 and iSeries: Installing RFC SDK for installation.
SAP NetWeaver RFC SDK
Central note for installing nwrfcsdk on IBM i is Note 1097997 - Installing SAP NW RFC SDK in system i. Details for compilation are given in Note 1056696 - Compiling and Linking RFC Programs with the SAP NW RFC SDK for all platforms.
For solution of the above problem you will now have to install the UNICODE version of nwrfcsdk into any directory /DIR independent of the 7.20 kernel. Subdirectory /DIR/nwrfcsdk/lib needs to be made visible to executables by adding this directory to the library path of the system. Note 1149088 - iSeries: Adding a directory to a work process simply explains that this can be done via parameter as4/ADDLIBPATH to the instance profile. Now you can configure connections in transaction SM59 using the full path /DIR/nwrfcsdk/bin/rfcexec or /DIR/nwrfcsdk/bin/startrfc.
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