WebSphere Application Server V8.5 Administration and Configuration Guide for the Full Profile

602 WebSphere Application Server V8.5 Administration and Configuration Guide for the Full Profile

17.1 Introduction to WebSphere Application Server for z/OS

V8.5 performance

WebSphere Application Server for z/OS V8.5 has version to version improvements of around

20% compared to WebSphere Application server V7. Some of these improvements are

described in this chapter.

End-to-end performance enhancements include:

 Up to 15% for DayTrader 2.0 running WebSphere V8.5 in comparison to the V7

 An additional 43% for DayTrader 2.0 running on a z196 machine in comparison to an IBM

System z10® machine

 Up to 24% for SOA Benchmark running WebSphere V8.5 in comparison to V7

 An additional 40% for SOA Benchmark running on an IBM System z196 machine in

comparison to a z10 machine

These numbers are informational only.

WebSphere Application Server for z/OS V8.5 also includes Java Virtual Machine J9 2.6 and

the following sets of native DLL libraries inside the delivered Java run time:

 31-bit version

 64-bit version

 64-bit version optimized for the z196 architecture

The Java specification is still V6 because there is no change in the application layer

interfaces, but it is enhanced to V6.0.1. WebSphere Application Server for z/OS V8.5 also

includes a new garbage collection mechanism and an optimized just-in-time (JIT) compiler.

WebSphere Application Server for z/OS V8.5 is hardware-platform aware and introduces

z196 hardware usage into the J9 JVM to use new instructions and paradigms, such as

out-of-order-execution pipeline and InfiniBand infrastructure for I/O bus or Parallel Sysplex

coupling.

This release focuses on the following areas:

 Optimized runtime performance for programming models

 Memory optimization and improvement of server startup time

 Improved installation time, application deployment, and configuration functions

 Improved runtime performance as a base for stack products

 Small, simple, and fast development environment

For more detailed information about performance improvements with WebSphere Application

Server for z/OS V8.5, go to the following website:

http://www-03.ibm.com/support/techdocs/atsmastr.nsf/5cb5ed706d254a8186256c71006d2e

0a/981aad32cbab471886257604001e1ec8/$FILE/WP101532%20-%20Why%20WebSphere%20Applica

tion%20Server%20for%20zOS%20-%20Notes.pdf

17.2 External factors and z/OS specifics

External factors, such as collocation and hardware configuration, can play an important role

in performance-tuning scenarios. In this section, we discuss the more common external

Chapter 17. Performance tuning 603

factors that can affect performance and provide suggestions for ways to obtain the best

performance possible.

17.2.1 Getting the most benefit from collocation

Collocation of the data layer and application layer can be beneficial during application

processing on the same system or in the same sysplex. Collocation provides the following

benefits:

 Takes advantage of cross-memory data transfer, reduces overall request latency, improves

overall throughput, and reduces overall CPU utilization through the elimination of network

traffic handling

 Allows for the assertion of security identity, maintains the same thread of execution, and

manages within a single Workload Manager (WLM) environment

17.2.2 Addressing hardware configuration

Hardware is also influential to overall system performance. Sources of performance boosts

include CPU, disks with parallel access volumes support, network cards and switch speed,

processor cache, system memory, and machine model. In this section, we list important

configuration settings to consider.

17.2.3 z/OS tuning tips

In this section, we provide information about z/OS tuning tips.

ZFS

Using cache-enabled and sysplex-aware z/OS Distributed File Service zSeries file system

(zFS) is preferred over the hierarchical file system (HFS). HFS generally provides better

response times for all types of operations.

You can verify the cache and average response time per operation type using the following

command:

F zfsproc,QUERY,ALL

Additional resource: For information about hardware configuration settings, go to the

following website:

http://pic.dhe.ibm.com/infocenter/wasinfo/v8r5/index.jsp?topic=%2Fcom.ibm.websp

here.installation.zseries.doc%2Fae%2Ftins_preparez.html

Additional resource: For more information about ZFS tuning, refer to z/OS Distributed

File Service zSeries File System Implementation z/OS V1R11, SG24-6580.