Chapter 2. iSeries and AS/400 RISC Server Model Performance Behavior
2.1 Overview
iSeries and AS/400 servers are intended for use primarily in client/server or other non-interactive work
environments such as batch, business intelligence, network computing etc. 5250-based interactive work
can be run on these servers, but with limitations. With iSeries and AS/400 servers, interactive capacity
can be increased with the purchase of additional interactive features. Interactive work is defined as any
job doing 5250 display device I/O. This includes:
RUMBA/400
Screen scrapers
Interactive subsystem monitors
Twinax printer jobs
BSC 3270 emulation
5250 emulation
All 5250 sessions
Any green screen interface
Telnet or 5250 DSPT workstations
5250/HTML workstation gateway
PC's using 5250 emulation
Interactive program debugging
PC Support/400 work station function
Note that printer work that passes through twinax media is treated as interactive, even though there is no
“user interface”. This is true regardless of whether the printer is working in dedicated mode or is printing
spool files from an out queue. Printer activity that is routed over a LAN through a PC print controller are
not considered to be interactive.
This explanation is different than that found in previous versions of this document. Previous versions
indicated that spooled work would not be considered to be interactive and were in error.
As of January 2003, 5250 On-line Transaction Processing (OLTP) replaces the term “interactive” when
referencing interactive CPW or interactive capacity. Also new in 2003, when ordering a iSeries server, the
customer must choose between a Standard Package and an Enterprise Package in most cases. The
Standard Packages comes with zero 5250 CPW and 5250 OLTP workloads are not supported. However,
the Standard Package does support a limited 5250 CPW for a system administrator to manage various
aspects of the server. Multiple administrative jobs will quickly exceed this capability. The Enterprise
Package does not have any limits relative to 5250 OLTP workloads. In other words, 100% of the server
capacity is available for 5250 OLTP applications whenever you need it.
5250 OLTP applications can be run after running the WebFacing Tool of IBM WebSphere Development
Studio for iSeries and will require no 5250 CPW if on V5R2 and using model 800, 810, 825, 870, or 890
hardware.
2.1.1 Interactive Indicators and Metrics
Prior to V4R5, there were no system metrics that would allow a customer to determine the overall
interactive feature capacity utilization. It was difficult for the customer to determine how much of the
total interactive capacity he was using and which jobs were consuming interactive capacity. This got
much easier with the system enhancements made in V4R5 and V5R1.
Starting with V4R5, two new metrics were added to the data generated by Collection Services to report
the system's interactive CPU utilization (ref file QAPMSYSCPU). The first metric (SCIFUS) is the
IBM i 6.1 Performance Capabilities Reference - January/April/October 2008
©
Copyright IBM Corp. 2008
Chapter 2 - Server Performance Behavior
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