zAAP on zIIP Capability

zAAP on zIIP capability

Beginning with z/OS V1.11, z/OS added a capability that can enable System z Application Assist Processor (zAAP) eligible workloads to run on System z Integrated Information Processors (zIIPs). This function can enable you to run zIIP- and zAAP-eligible workloads on the zIIP. This capability is ideal for customers without enough zAAP- or zIIP-eligible workload to justify a specialty engine today; the combined eligible workloads may make the acquisition of a zIIP cost effective, and may simplify planning activities. This 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. Its purpose is not as an overflow capability for zAAP eligible workload to run on the zIIP, rather it enables zAAP eligible work to run on a zIIP engine when no zAAP is defined on the server.

Requirements include

Planned Support for zAAPs and zIIPs

The IBMzEC12 and IBM zBC12 are planned to be the last System z servers to offer support for zAAP specialty engine processors. IBM intends to continue support for running zAAP workloads on zIIP processors (“zAAP on zIIP”).Customer should consider planning for further use of zIIPs or alternatively, zAAPs on zIIPs.

Simplified Testing for zAAP on zIIP

Also IBM APAR OA38829 for z/OS V1.12 and z/OS V1.13 removes the restriction that prevents zAAP-eligible workloads from running on zIIP processors when a zAAP is installed on the server. This is intended for migration and testing purposes only, to facilitate migration of zAAP workloads onto zIIP processors.

Contact IBM

Browse System z


IBM provides world-class IBM mainframe technology to help today's enterprises respond quickly to evolving business conditions and with extreme flexibility. From automation to advanced virtualization technologies and open industry standards, IBM mainframes help deliver competitive advantages for enterprises contributing and succeeding on a smarter planet.

Operating Systems

IBM System z supports multiple operation systems:


IBM's technology, solutions and industry expertise can help you find the competitive edge with a sharper understanding of your customers. Our System z solutions combine the foundation of IBM hardware, software and middleware with flexible financing and packaging options to help your business meet and overcome the challenges of doing business in the on demand world. IBM can help you develop a customer-centric view—and assist you in delivering the right solution and the right products.