CA Plex: Upgrade from Plex 5.5 to 7.2.1

Products

• CA Plex

Issue/Introduction

Planning the migration of models from 5.5 and 6.1 to 7.2.1. The models are working with C++/RPG and Java/RPG. 
From the documentation need to rebuild and gen the C++ portion with VS 2013 and the Java portion with JDK 1.8. Don't need to regenerate RPG, right? 
The current 6.1 dispatcher or listener installed in the IBM i, does the one that comes with Plex 7.2.1 need to be installed and it is backward compatible?  Or, will 2 listeners be needed on the IBM i?

Resolution

In the Plex documentation, please review the following link. 

https://docops.ca.com/ca-plex/7-2-1/en/release-information/upgrading-from-earlier-releases#UpgradingfromEarlierReleases-UpgradingfromCAPlexr5.5 

In the link there is the following section. 

RPG Functions Upgrade Requirements 
You do not need to regenerate or rebuild existing RPG functions when upgrading to CA Plex r7.2.1. 

Additional clarification:  
Plex WinC/WinNTC functions are mandatory to regen/rebuild due to compiler changes. System-I Plex RPG objects are not mandatory to rebuild. 
To upgrade to Plex r7.2.1, you need to install Plex r7.2.1 dispatcher on IBM-i and new dispatcher will work fine with existing RPG built objects. 
And make sure you have Plex r7.2.1 client runtime (WinC/WinNTC) installed at Plex client application side.