If you are not already using zEDC
Enable zEDC for an application.
Ensure that z/OS input buffers specified in your Java application are large enough to qualify for hardware compression. To see the minimum size for compression and decompression, issue the D IQP command and check the values for DEFMINREQSIZE and INFMINREQSIZE in the response. (These values are static.) Use the environment variables _HZC_DEFLATE_THRESHOLD and _HZC_INFLATE_THRESHOLD in your application to control the minimum buffer sizes that must be met for hardware compression. For the best experience, use larger buffers for compression, such as 32KB - 256KB, rather than small buffers such as 256 bytes. Small buffers work very well, but large buffers are better.
For C applications, link or re-link the application to use the IBM-provided zlib.
Path for the zlib archive file: /usr/lpp/hzc/lib/libzz.a
Path for the zlib header files: /usr/lpp/hzc/include/
Re-link an application when a new service is provided in zlib in order to use the updated zlib and take advantage of the new function. zlib will always be compatable -- Integrated Accelerator for zEDC will never break zlib’s ability to call into the operating system to get accelerated compression.
If you are already using zEDC
Ensure that the z/OS input buffers for the Java application are sufficient for what is listed for DEFMINREQSIZE and INFMINREQSIZE displayed with the D IQP command.
You do not need to re-link the application to use the IBM-provided zlib.
Assess and complete:
- Run the application.
- Assess the compression. For performance metrics, use:
- SMF record type 113 for synchronous processing. (zlib is always synchronous on a z15.)
- SMF record type 30 to see the change in elapsed time and CPU time for the job.
- If necessary, adjust your application and run it again.
- Put the application into production.