September 18, 2012

zEC12 and zIIP Processors

Following up on last week's post about the zEnterprise EC12, IBM has just come out with a new Redbook, the "IBM zEnterprise EC12 Technical Guide."

As the title suggests, this publication is technical. However, even if you're not a hardware or OS guru, I think you'll get something out of it, if only for the pictures. No, that's not a putdown of you less technical folk; the illustrations and images that explain the zEC12 technology are really quite interesting. They allow you to see -- as I did -- just what an amazing machine the zEC12 is.

The zEC12 is designed to run z/OS, z/VM, z/VSE, z/TPF, Linux on System z (SUSE Linux and RedHat). On the zBX blades you can run POWER7 hardware with AIX, PowerVM, Linux on System x (SUSE SLES and Red Hat), Windows Server 2008 R2 and Windows Server 2008 SP2 (Datacenter Edition) 64-bit.

Since I work with z/OS and DB2, I’m very interested in specialty processors such as zAAP, zIIP and IFL. The zAAP processor is designed to offload Java workload, zIIP for DB2 workloads (such as DRDA access over TCP/IP, JDBC, ODBC, parallel queries, XML parsing and some DB2 utilities) and IFL for Linux workloads. 

I recently learned that zAAP workloads can run on a zIIP specialty engine if you don't have a zAAP processor. I wasn't sure this has been supported on z/OS, but I searched around and found this great cheat sheet about zAAP and zIIP parameters. Looking at this document I see that z/OS 1.11 provides this support using the parameter, ZAAPZIP=YES. By applying APAR OA27495, you can use parameter zz=YES on 1.9 and 1.10.

All this made me wonder why a customer would buy a zAAP specialty engine when both Java and DB2 workloads can now run on a zIIP. The answer comes in this IBM statement of direction:

"IBM zEnterprise EC12 is planned to be the last high-end System z server to offer support for zAAP specialty engine processors. IBM intends to continue support for running zAAP workloads on zIIP processors (zAAP on zIIP). This is intended to help simplify capacity planning and performance management, while still supporting all the currently eligible workloads. In addition, IBM plans to provide a PTF for APAR OA38829 on z/OS V1.12 and V1.13 in September 2012 to remove the restriction that prevents zAAP-eligible workloads from running on zIIP processors when a zAAP is installed on the server. This is intended only to help facilitate migration and testing of zAAP workloads on zIIP processors."

I’m sure this will greatly help customers plan their hardware upgrades, because it removes the need to guess how much new workload will be Java or how much will be DB2 for z/OS work. Instead of having to purchase another zAAP engine or a zIIP engine, now customers can just buy zIIP engines and know they'll handle both Java and DB2 workloads.