Assist processors
Assist Processor (English, also specialty processors ) are CPUs , which on IBM Mainframes type System z , are used to regular processors to relieve certain tasks. The user can determine which identity (normal CPU or Assist CPU) the CPUs should have in the system. In addition, Assist Processors are not taken into account when calculating license fees for software, which is dependent on the processor performance. Assist processors always run at full (model-dependent) speed. Normal CPUs can run slower to save license costs. Technically, the Assist Processors do notdifferfrom the normal CPUs. The use of the processors is onlylimitedby the firmware and the operating system to certain applications in the system.
Types of Assist Processors
Integrated Facility for Linux (IFL)
The IFL is a specialty processor for running the z / VM , Linux and OpenSolaris operating systems on System z.
Internal Coupling Facility (ICF)
Internal Coupling Facility Processors are used to provide the coupling facility functionality in an LPAR .
Application Assist Processors zAAP
System z Application Assist Processors ( zAAP ) allow Java applications to be executed. Work can be carried out on the zAAP when the Java Virtual Machine (JVM) informs the dispatcher that a JVM code is being processed. Execution on the zAAP is retained until the Java program has been processed or a system service call causes a return to the regular processor. With the introduction of zAAPs, the execution of Java-based applications under WebSphere , CICS , IMS and Db2 under z / OS is made more attractive. ZAAPs can also use certain system functions for processing data in XML format.
System z Integrated Information Processors (zIIP)
zIIPs are used to offload a certain type of work from the regular processors. The proportion of the work to be outsourced depends on the system component or middleware that makes use of this technology. First zIIPs were from Db2 exploited to a certain percentage of DRDA outsource requirements, there star schema table access, LOAD, REORG and REBUILD processings. A growing number of applications can now run on zIIPs.