What is PASE for i?
According to IBM, “PASE for i provides an integrated runtime environment that allows you to run selected applications without the complexity of managing operating systems, such as AIX or Linux.”
If you are going to deploy open source solutions on the IBM i platform, it is imperative that you become familiar with PASE (Portable Application Solution Environment). Open source solutions run on IBM i via PASE.
Zend Server, PHP, and MySQL/Mariadb have run on IBM i via PASE for many years.
The PASE architecture
Some think that PASE is an emulated environment, while others think that PASE is an environment separate from IBM i.
Both are wrong!
Consider the following diagram:
Let’s consider the “PASE Applications” area on the left side of the diagram.
PASE provides a set of AIX shared libraries that runs directly on the POWER processor. Because there’s no emulation involved, PASE provides performance equal to native AIX applications.
The diagram also shows a syscall interface that enables applications running in PASE to access the Integrated Language Environment (ILE) to call ILE applications and access DB2 resident data.
PASE and OSS
Open source languages like PHP and Python use the syscall interface to leverage the IBM-supplied XML toolkit to bridge outside of PASE and leverage ILE programs and artifacts.
It’s important to keep in mind that PASE is an environment native to the IBM i hardware. PASE and its applications run in subsystems within IBM i. For example, the latest version of PHP runs in the ZENDPHP7 subsystem via PASE.
PASE has access to the Integrated File System (IFS), which means that file operations performed inside of PASE are reflected within the IFS.
Hopefully this post has provided an understanding of the PASE architecture that facilitates both the execution of open source solutions and leveraging of the ILE by those solutions.
In addition to understanding the architecture, you’ll want to understand how to work within the PASE environment. I will cover that in a future blog post.
Interested in open source solutions on IBM i? Rogue Wave Software has a team of Enterprise Architects that would enjoy talking to you about how open source solutions can help you build efficient solutions that provide added functionality to your business.
Feel free to reach out to us at email@example.com.