IBM z/OS - Manual (Page 7)

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The new IBM ^ zSeries Application Assist
Processor (zAAP), planned to be available on the IBM
^ zSeries 990 (z990) and zSeries 890 (z890) serv-
ers, is an attractively priced specialized processing unit
that provides strategic z/OS Java execution environment
for customers who desire the powerful integration advan-
tages and traditional Qualities of Service a of the zSeries
platform.
When confi gured with general purpose Central Processors
(CPs) within logical partitions running z/OS, zAAPs can
help you to extend the value of your existing zSeries
investments and strategically integrate and run e-business
Java workloads on the same server as your database,
helping to simplify and reduce the infrastructure required
for Web applications while helping to lower your overall
total cost of ownership.
zAAPs are designed to operate asynchronously with the
general purpose CPs to execute Java programming under
control of the IBM Java Virtual Machine (JVM). This can
help reduce the demands and capacity requirements
on general purpose CPs which may then be available
for reallocation to other zSeries workloads. The amount
of general purpose CP savings may vary based on the
amount of Java application code executed by zAAP(s).
And best of all, IBM JVM processing cycles can be
executed on the confi gured zAAPs with no anticipated
modifi cations to the Java application(s). Execution of the
JVM processing cycles on a zAAP is a function of the IBM
Software Developer’s Kit (SDK) for z/OS Java 2 Technology
Edition, z/OS 1.6 (or z/OS.e 1.6) and the innovative
Processor Resource/Systems Manager ™ (PR/SM ™ ).
Notably execution of the Java applications on zAAPs,
within the same z/OS LPAR as their associated database
subsystems, can also help simplify the server infrastruc-
tures and improve operational effi ciencies. For example,
use of zAAPs to strategically integrate Java Web applica-
tions with backend databases could reduce the number of
TCP/IP programming stacks, fi rewalls, and physical inter-
connections (and their associated processing) that might
otherwise be required when the application servers and
their database servers are deployed on separate physical
server platforms.
Essentially, zAAPs allow customers to purchase additional
processing power exclusively for z/OS Java application
execution without affecting the total MSU rating or machine
model designation. Conceptually, zAAPs are very similar to
a System Assist Processor (SAP); they cannot execute an
Initial Program Load and only assist the general purpose
CPs for the execution of Java programming. Moreover,
IBM does not impose software charges on zAAP capacity.
Additional IBM software charges will apply when additional
general purpose CP capacity is used.
Customers are encouraged to contact their specifi c ISVs/
USVs directly to determine if their charges will be affected.
With the introduction of the z990, customers can expect to
see the following performance improvements:
Number of CPs Base Ratio
1 z900 2C1 1.54 - 1.61
8 z900 2C8 1.52 - 1.56
16 z900 2C16 1.51 - 1.55
32 z900 2C16 2.46 - 2.98
Note: Greater than 16 CPs requires a minimum of two operating
system images
The Large System Performance Reference (LSPR) should
be referenced when considering performance on the z990.
Visit: ibm.com/servers/eserver/zseries/lspr/ for more infor-
mation on LSPR.