Work Management

1
Work Management Performance

• Chapter 14

2
Overview

• The AS/400 combines the pieces of Managing
  Devices, Working with Jobs, and Working with
  Subsystems to run programs

• Pieces fit together performance testing

3
What makes a job run?

• Devices
• Job Descriptions
• Job Classes
• Job Queues
• Subsystems with
• Routing entry(s)
• Job queue entries batch SBS
• Workstation entry(s) interactive SBS
• Communication entry(s) communication SBS
• A valid user ID or password

6 necessary things
4
How the AS/400 runs

• Interactive Jobs
• WS device known
• Valid sign-on
• SBS with job description and class
• WSE
• Routing Entry

• Batch Jobs
• How batch jobs are started
• SBMJOB
• Communication PGM start request
• Auto-start jobs
• Pre-start jobs

5
How the AS/400 runs

• Communication Jobs
• A hybrid between interactive and batch jobs
• Remote system start
• Communication entry needed

6
Subsystems

• QBASE and QCTL
• SYSOPR should
• QCMN
• QINTER
• QBATCH
• QSPL

7
Performance

• AS/400 has ability to constantly tune resources
  while jobs are running
• Document all efforts

8
Automatic Performance Tuning

• Two system values
• QDYNPTYSCD
• prevents gobbling resources
• QPFRADJ
• manages pool memory allocations
• Manual monitoring is still a good idea

9
Why Manually Monitor?

• DPS is quick to reset changes priorities after
  they have been lowered
• SYSOPR may want it low
• SYSOPR may want a PGM to be a hog
• Sometimes user response-time complaints are due
  to transmission time across a busy or large LAN.
  (AS/400 performance tools dont address this
  because it takes place outside the AS/400)

10
Emergencies What do I do?

• An operator should be concerned with 2 areas
• Overall CPU
• Over 100 indicated by
• CPU for individual jobs

11
WRKACTJOB
12
Why is CPU high?

• 3 Reasons
• Programs are complex
• Page faulting is causing a lot of extra disk IO
• Overall load on the system ( of jobs) is too high

13
Recommendations Vs. Reality

• IBM recommends
• below 70 for single-processors
• Below 81 for a four-way processor
• Systems without noticeable performance problems
  will typically run in the 90 range
• Remember CPU utilization over 90 gets hammered
  from excessive seize/lock conflicts

14
What Next?

• CPU over 90 - even if normal - continue
  searching for problem within the AS/400
• CPU good (approx 75), hang-up may be due to
  lost device on LAN

Response time problem low CPU
Suspect LAN
15
Work With Active Jobs Example

• Largest CPU - F16 re-sequences by specified
  column
• Some programs need a lot of horsepower
• Confirm big jobs are necessary (while holding -
  3)
• If necessary, lower the job priority (higher )

16
Problem still exists?

• WRKSYSACT (Work System Activity)
• Screen refreshes every five seconds
• System tasks and their CPU is displayed
• Dont normally appear on WRKACTJOB screen
• Cancel the user job and the system tasks will go
  with it

17
Emergency Aftermath

• New priorities require time to take affect
• Recovery period could cause worse damage
• LAN failure disconnect users, sessions dumping
  logs and cleaning up after themselves
• lots of activity
• Announcements Sign back on
• Performance will die 15 to 45 minutes

18
TIPS

• Develop guidelines for performance emergencies
• Always use Performance tuning
• Monitor performance during busiest time
• Modify system parameters (changing activity
  levels or memory) during less busy times
• REMEMBER Monitoring is an ongoing process
• If the System Operator has the AS/400 properly
  tuned, performance emergencies are less likely to
  occur

19
TIPS (Cont.)

• Performance Tools/400 has powerful
  data-collecting and reporting tools
• STRPFRMON
• ADDPFRCOL
• ANZPFRDTA
• PRTTNSRPT
• Best/1 is a built-in capacity-planning product
• Use SETOBJACC to preload entire files into
  dedicated pools for certain kinds of processing

20
AS/400 Servers

• Tuned to favor batch processing, leave them that
  way
• A few WS will make the interactive CPU go to
  10 and then nothing will run well
• IBM recommends less than 2 of the interactive
  CPU