On August 18, 2009 IBM announced z/OS V1.11. This announcement contained many new and improved features and capabilities, including failure avoidance, simplified management via a new z/OS Management Facility (5655-S28), responsive networking, enhanced security features, improved accountability, optimization improvements and storage scalability.
But within this announcement was an interesting new capability to enable zAAP-eligible workloads to run on zIIPs. This can be a boon to some shops that only have is zIIPs. Now, with zAAP on zIIP support, you can use zIIP processors for both Java and distributed DB2 workloads. In the announcement, IBM promotes this capability as being "ideal for customers without enough
zAAP- or zIIP-eligible workload to justify a specialty engine today; the combined
eligible TCB and enclave SRB workloads might make the acquisition of a zIIP
cost effective.This new capability is also intended to provide more value
for customers having only zIIP processors by making Java- and XML-based workloads
eligible to run on existing zIIPs."
Perhaps another way of looking at this is that some shops were not getting sufficient work redirected to zIIPs. I visit DB2 customers regularly as part of my job and some of them were disappointed in the amount of work that was able to be run on their zIIPs. Unless you have a lot of DB2 DRDA workload, it is likely that your zIIP processors will be under-utilized. But the new zAAP on zIIP capability gives customers the opportunity to run additional workload (Java and XML processing) on their zIIP processors.
To take advantage of zAAP on zIIP, you need to be running z/OS V11.1 (or z/OS V1.9 or V1.10 with the PTFs for APAR OA27495)
on a z9 or z10 server. Furthermore, this will not be available to you if you already have zAAP(s) installed.
Keep in mind, too, that the terms for specialty processors do not change. You can only have 1 zAAP and 1 zIIP per each general purpose processor. So, even if you have zAAP on zIIP configured, the chip is still a zIIP and you cannot have any more than 1 per general purpose processor.
For more information on specialty processors in general, check out my previous blog posting on the topic: Specialty Processors on the Mainframe.