MVS Jan 2005.p65 - CBT Tape

With IFAHonorPriority = No, Java work can only use available
CP capacity if there is no other non-Java work waiting to
execute. It can be used when the Java workload is to use
standard CP only when there is no other workload.
zAAP PROJECTION TOOL
According to IBM, ‘While zAAPs are capable of executing up
to 100% of Java cycles, the reality is that most applications
are not 100% Java’. It is estimated that around 50% to 70% of
the actual Java workload will be off-loaded to zAAP.
The amount of Java application code executed by zAAP(s) is
dependent on the amount of Java cycles used by the relevant
application(s) and on the zAAP execution mode selected.
Hence, the amount of general purpose processor saved and
in turn the cost benefits are expected to vary depending on the
customer.
To allow the customers to get an idea of the potential savings
they can achieve by running their Java application in zAAP,
IBM has also announced the zAAP Projection Tool. This tool
basically collects the usage information of how much CPU
time is used in executing Java code and categorizes it as
eligible for the zAAP or not eligible. It is designed so that only
code written in Java and Java system native code is enabled
to run on a zAAP.
You can run a Java workload representative of your production
load and, through the Java log, this tool will report how much
of the workload would potentially be shipped to zAAP.
The tool runs under Java 2 Technology Edition, SDK 1.3.1,
and hence can be used with lower versions of software than
required for exploiting zAAP – for example with WAS 5.0 and
CICS 2.2.
This tool is useful in determining whether it is worth moving
towards zAAP and, if so, the number of zAAPs that would form
the optimal configuration for your workload.
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