What is the decoupled method of installing PeopleSoft?
The decoupled method, supported as of PeopleTools 8.52 with applications at release 9.1 fp2 and above, is a scenario where the PeopleTools codeline is installed to a directory separate from the application codeline.
The directories used are referred to as "Ps_Home" and "Ps_App_Home".
In addition, any customizations to file system objects such as sqrs, crystal reports, or Cobol programs, could be installed to a separate directory. This is referred to as "Ps_Cust_Home".
So, you would have locations "Ps_Home", "Ps_App_Home", and "Ps_Cust_Home" with different directory values.
Translation data, if the install is multilanguage, is installed to the Ps_App_Home.
This method of installation is optional. If you choose to install all codeline into one directory, referred to as Ps_Home, this is your choice. This is called the Classic method of installation. The parameters "Ps_Home", "Ps_App_Home", and "Ps_Cust_Home" would then be set to the same value.
The configuration files for for the application server, batch server and search server domains would still be installed to Ps_Cfg_Home. This is done for security reasons. Placing the configuration files in their own Ps_Cfg_Home does not make for a decoupled installation.
Why would this be done?
Benefits to the decoupled installation method would include modularity and flexibility.
Is the decoupled method a required method of installing?
No, it is optional. An acceptable install method is still the Classic method, where all codelines are installed to one directory, referred to as Ps_Home. In the Classic method, the directories for Ps_Home, Ps_App_Home, and Ps_Cust_Home are set to the same value.
What are commonly asked questions about the decoupled method of installation?
1) Guidelines for compiling Cobol in a decoupled installation.
For information on this topic, see PeopleTools 8.53+ Install Guides, section Understanding COBOL Compilation with PeopleSoft Installation Locations.
2) Confirming releases supported with this installation method.
See above, plus, support for this method of installation can be found in the Application install guides.
3) Implementation of a decoupled installation during a Tools Only Upgrade or during an Application and Tools Upgrade.
See the White Paper PeopleTools Mid-Tier Deployment Best Practices (Doc ID 1448479.1), which was updated for the PT8.54 release in July 2014.
4) Setting up the EMF Hub in a decoupled installation
See document E-CA StartAgent Recrawl: Unable to find psae executable at null/bin/server/winx86 (Doc ID 1223793.1).
When preparing for a PT8.54 PeopleTools Only Upgrade, is the decoupled installation required?
As part of a PeopleTools-only upgrade, you will need to install a the 8.54 PeopleTools codeline to a separate Ps_Home for use in the upgrade. This is the installed Source codeline for the Tools Only Upgrade.
At the conclusion of the PT8.54 PeopleTools Only Upgrade, the PT8.54 codeline can be installed over the Target Ps_Home for use as the new Ps_Home. Or, if you were already decoupled prior to starting the upgrade, then simply switch over to the newly installed PT8.54 PS_HOME after completing the upgrade.
If you choose to implement a decoupled configuration after completing the upgrade, be sure your application supports it. This information can be found in the Application Installation Guide for your application / release. Otherwise you must continue to use the classic deployment until you are ready to upgrade your Application to a release that supports decoupled homes. If you wish to continue using the classic deployment, simply install the new PeopleTools release into your existing coupled PS_HOME after completing the upgrade.
Are there problems with using PUM, in a decoupled installation?
No. You will see the entry areas for directories Ps_Home, Ps_App_Home, and Ps_Cust_Home in the Change Assistant when defining databases.
To learn more
See the PeopleTools 8.52, 8.53, 8.54 installation guide for your database platform, section Defining Installation Locations, for more information on installing to directories:
Ps_Home, Ps_App_Home, Ps_Cfg_Home, Ps_Cust_Home, and Pia_Home.
PeopleSoft PeopleTools 8.54 Installation Home Page [1905010.1]
PeopleBooks > PeopleTools 8.54 > System and Server Administration > Working with Ps_App_Home.
E-INST Installation methods: Classic PsHome, PS_APP_HOME, and PS_CUST_HOME (Doc ID 1557074.1)
E-CA How does Change Assistant Identify PS_APP_HOME for Deploying Files? (Doc ID 1506618.1).
White Paper PeopleTools Mid-Tier Deployment Best Practices (Doc ID 1448479.1 (updated July 2014)