System z Application Assist Processor (zAAP)

Today's reality

Today, business requirements change more frequently than ever. To stay current and competitive, businesses are developing new strategic web-based applications, but these applications typically require more IT resources than traditional applications due to levels of abstraction, code generation, and reuse.

What it does

The IBM System z Application Assist Processors (zAAPs) is available on all IBM zEnterprise, IBM System z10, IBM System z9, IBM eServer zSeries 990 (z990) and IBM eServer zSeries 890 (z890) systems. The zAAP specialty engine provides an attractively priced execution environment for new web-based applications and SOA-based technologies, such as:

• Java™ - for customers who desire the powerful integration advantages and traditional Qualities of Service of the IBM mainframe platform.
• XML — for customers who desire cost effective XML parsing services on z/OS, z/OS XML System Services can exploit the zAAP for eligible XML workloads.

What it means

Java

For Java workloads, zAAPs may enable customers to:

• Simplify and reduce server infrastructures by integrating Java Web applications mission critical data for high performance, reliability, availability and security.
• Maximize the value of their mainframe investments through increased system productivity by reducing the demands and capacity requirements on general purpose processors which may then be available for reallocation to other mainframe workloads.
• Lower the overall cost of computing for WebSphere Application Server and other Java technology-based applications; through hardware, software and maintenance savings.

When configured with general purpose processors within logical partitions running z/OS, zAAPs may help increase general purpose processor productivity and may contribute to lowering the overall cost of computing for z/OS Java technology-based applications. zAAPs are designed to operate asynchronously with the general processors 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 processors which may then be available for reallocation to other mainframe workloads.

The IBM JVM processing cycles can be executed on the configured zAAPs with no anticipated modifications to the Java application(s).

The amount of general purpose processor savings will vary based on the amount of Java application code executed by zAAP(s). This is dependent upon the amount of Java cycles used by the relevant application(s) and on the zAAP execution mode selected by the customer.

Execution of the Java applications on zAAPs, within the same z/OS SMP LPAR as their associated database subsystems, can also help simplify the server infrastructures and improve operational efficiencies. For example, use of zAAPs could reduce the number of TCP/IP programming stacks, firewalls, and physical interconnections (and their associated processing latencies) that might otherwise be required when the application servers and their database servers are deployed on separate physical server platforms.

IBM does not impose software charges on zAAP capacity. Additional IBM software charges apply only when additional general purpose CP capacity is used. Customers are encouraged to contact their specific ISVs/USVs directly to determine if their charges will be affected.

XML

For XML workloads, zAAPs may enable customers to:

• Simplify and reduce server infrastructures by developing XML-based applications and integrating them with existing data stores.
• Collectively, z/OS XML System Services support of zAAP and zIIP means that you have the advantages of XML processing on z/OS with TCO benefits of either the zIIP or the zAAP processor.

With z/OS V1.10 z/OS XML System Services validating and non validating parse requests executing from TCB mode can be eligible for the zAAP. z/OS XML System Services (z/OS XML) is a system-level XML parser integrated with the base z/OS operating system starting with z/OS V1.8 and is designed to deliver an optimized set of services for parsing XML documents (z/OS XML System Services has also been made available on z/OS V1.7).

z/OS XML System Services eligibility for zAAP was rolled out over time. With z/OS V1.9, all z/OS XML System Services validating parsing executing in TCB mode were made eligible for the zAAP.

Many IBM applications use z/OS XML System Services and, as a result, can have portions of their workloads eligible for the zAAP or zIIP processor. They are summarized here:

• Software that uses z/OS XML System Services for non-validating parsing executing in TCB mode
  • DB2 9 pureXML
  • any local (z/OS) SW using z/OS XML System Services parsing in TCB
    • EXAMPLE : local applications inserting/ saving XML data, and XML table loads on DB2 9
  • XML Toolkit for z/OS V1.9 parsing workloads
  • Enterprise COBOL V4.1, using XMLPARSE (XMLSS) option
  • Enterprise PL/I V3.8 using PLISAXC built-in subroutine
  • CICS TS V4.1 for partial inbound SOAP messages
• Software that uses z/OS XML System Services for non-validating parsing in enclave SRB mode
  • DB2 9 pure XML inserting/ saving XML data over DRDA via TCP/IP
  • any software using z/OS XML System Services in enclave SRB mode
• Software that uses z/OS XML System Services for validating parsing.
  • XML Toolkit for z/OS V1.10 workloads (TCB mode)
  • any SW using z/OS XML System Services validating parsing (TCB mode)
  • Enterprise COBOL V4.2, using XMLPARSE (XMLSS) option (TCB mode)
  • DB2 10 pureXML (TCB mode for local connectivity, enclave SRB mode for remote TCP/IP over DRDA connectivity)

For example, DB2 9 utilizes z/OS XML System Services non-validating parsing for a portion of its SQL/ XML processing. For applications (queries) running locally on z/OS, XML data is inserted or updated, or when XML data is loaded into tables, DB2 9 invokes z/OS XML System Services (which exploits zAAP, when present). The remaining DB2 9 XML processing is performed on general purpose CPs, Java-based stored procedures are eligible for zAAP. NOTE: DB2 10 utilizes z/OS XML System Services for both validating and non-validating parsing.

In addition, the IBM XML Toolkit for z/OS, V1.9 is enhanced so eligible workloads can use z/OS XML System Services non-validating parsing. This means eligible XML Toolkit processing (for non-validating parse requests) can exploit the zAAP and also obtain improved performance. This function is available on the XML Toolkit for z/OS V1.9 with PTFs UA40707 and UA40708. IBM Enterprise COBOL V4.1 was enhanced with a new XML parse facility that allows the optional use of z/OS XML System Services and the zAAP, when present.