Compression options on distributed XCOM platforms (non z/OS)

Products

• XCOM Data Transport
• XCOM Data Transport - Linux PC
• XCOM Data Transport - Windows
• XCOM Data Transport - z/OS

Issue/Introduction

What are the XCOM compression options/routines available on non-z/OS (distributed) OS platforms?
In particular is ZLIB available on all n0n-z/OS platforms?

Environment

• XCOM™ Data Transport® for Windows releases 11.6, 12.0
• XCOM™ Data Transport® for UNIX/Linux PC releases 11.6, 12.0
• XCOM™ Data Transport® for AS/400 release 11.0

Resolution

In addition to XCOM for z/OS, XCOM for Windows and XCOM for UNIX/Linux have supported the ZLIB* compression types since several releases back, so transfers between any of those OS platforms can use it.
The information in this older KB is also still accurate: XCOM available compression options - ZLIB1 through ZLIB9

In more detail:

Windows
11.6:

• How to Provide Performance Tuning - see "Enable/Disable Compression".
• Parameter COMPRESS (XCOM.CNF) or COMPRESS.

12.0:

• Review the Performance Tuning Best Practices - see "Review Your Compression Settings"
• Parameter COMPRESS - NOTE: reduced number of options per Obsolete Features
  
  
  

UNIX/Linux
11.6:

• Parameter COMPRESS.

12.0:

• Parameter COMPRESS - NOTE: reduced number of options per Obsolete Features
  
  

Other platforms:
AS/4000

11.0:

• Performance Considerations - see "Data Compression"
• The COMPRESS parameter does not include ZLIB* options.

Additional Information

1. For which compression type/algorithm to use, this is very much site dependent and tests need to be run in own environment. A few years ago internal tests found the use of ZLIB2 was the preferred compression method, but testing the various options in own environment is strongly recommended.

2. With modern network speeds being a lot faster the benefit of compression may not be as great. It is prudent to run tests using record packing with and without compression because compression may not be as beneficial due to the trade-off with its increased CPU usage. For record packing please review:
Windows: XCOM™ Data Transport® for Windows 11.6 Service Packs > Using > How to Provide Performance Tuning - see "Transfer Big Blocks". Also CARRIAGE_FLAG.
UNIX/Linux: CARRIAGE_FLAG