F E E T O N T H E G R O U N D

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International Computers Ltd 1999Slide Slide 11

5 Things to do with LUS5 Things to do with LUS and then how to answer the next set o and then how to answer the next set of

questionsquestions

CMUG focus GroupCMUG focus Group

John Popplewell

ICL

john.popplewell@icl.com

F E E T O N T H E G R O U N D

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International Computers Ltd 1999Slide Slide 22

LUSLUS

• Why do you use it?

– Absolute measure of resources used within a job

• OCP, number of IO’s etc

– But it doesn’t give any measure of resource queuing• How long have I spent waiting for the processor?

– Excellent in a dedicated system, limited otherwise!

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International Computers Ltd 1999Slide Slide 33

What can take resources in a job?What can take resources in a job?

OCPOCP OCPOCPQueuingQueuing

IO TimeIO Time VSI TimeVSI Time OtherOther

F E E T O N T H E G R O U N D

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International Computers Ltd 1999Slide Slide 44

LUS(Breakdown)LUS(Breakdown)

• A job has 5 components, LUS can measure some of the components, help you ESTIMATE the others

– OCP time – Queuing for OCP time – IO time – VSI time – Other

• For the following example I am going to assume that queuing for OCP is negligible, this is almost certainly not true for all cases

F E E T O N T H E G R O U N D

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International Computers Ltd 1999Slide Slide 55

DeploymentDeployment

LUS(BREAKDOWN)

run the job or job step

LUS(BREAKDOWN)

F E E T O N T H E G R O U N D

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International Computers Ltd 1999Slide Slide 66

LUS(Breakdown)LUS(Breakdown)

USAGE DURING PREVIOUS 14655 SECS

TIME(SEC) : 1407 VS INTERRUPTS : 732 MS OCC(MB-SEC) : 45404 RIRO COUNT : 0

INST(M-PLI) : 7521 DRUM XFERS(PAGES) : 0 CURRENT PAGES : 912 LSUSPENDS : 0

FS XFERS : 682812 DISC XFERS(PAGES) : 0 AVERAGE PAGES : 3098

ACCESSS LEVEL: 1 2 3 4 5 6 7 8 9 10 11 12 13-15

VSIS : 0 0 1 40 651 0 0 5 0 35 0 0 0

DISC TRANSFERS: USER 681047 FILE ORGANISATION: 407 DIRECTOR(PUBLIC/LOCAL): 30/1328

TAPE TRANSFERS: USER 0

F E E T O N T H E G R O U N D

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International Computers Ltd 1999Slide Slide 77

LUS(Breakdown)LUS(Breakdown)

1 Calculate the OCP utilisation

= time/elapsed time

= 1407/14655

=9.6%

F E E T O N T H E G R O U N D

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International Computers Ltd 1999Slide Slide 88

LUS(Breakdown)LUS(Breakdown)

2 Calculate IO Time

Assuming no OCP queuing and no other! [synchronous IO IDMS]

IO time = (Elapsed time - OCP time) / Elapsed time= (14655 - 1407)= 13248 secs

IO percentage = (Elapsed time - OCP time) / Elapsed time= (14655 - 1407) / 14655= 90.4%

F E E T O N T H E G R O U N D

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International Computers Ltd 1999Slide Slide 99

LUS(Breakdown)LUS(Breakdown)

3 Calculate the IO rate [determine if IO response time an issue]

= total IO’s / IO time= 862812 / 13428= 64.3 IO’s per second

or each IO takes 15.5 milliseconds

� I expect IO’s to take � between 5msecs (SA serial read) � to 40 ++ msecs (GD random access)

� Most in 17 => 30 msec range

F E E T O N T H E G R O U N D

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International Computers Ltd 1999Slide Slide 1010

LUS(Breakdown)LUS(Breakdown)

4 Set Quota to

AVERAGE PAGES as recorded by LUS3000 is close enough

Could also determine VSI rate

F E E T O N T H E G R O U N D

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International Computers Ltd 1999Slide Slide 1111

LUS(Breakdown)LUS(Breakdown)

5 See if the INITIAL file sizes are large enough

If FILEORGANISATION is smallthen INIT SIZES OKelse

Increase INIT sizes

Given that IO’s take ~17 -30 msecs then “small” is a function of time

eg 1000 file organisation xfers takes 20,000 msecs = 2 seconds

F E E T O N T H E G R O U N D

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International Computers Ltd 1999Slide Slide 1212

What do you do nextWhat do you do next

• So the 5 steps to enlightenment didn’t get you above the basement!

• What do you do next!!

• You need to get a handle on queuing

• How do you do that?

F E E T O N T H E G R O U N D

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International Computers Ltd 1999Slide Slide 1313

What do you do next?What do you do next?

• Elapsed_Time_Monitor

• ETM

• Gives you

• OCP queuing

• IO Time

• Other (semaphores, long suspension, VSI etc)

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International Computers Ltd 1999Slide Slide 1414

DeploymentDeployment

LUS(BREAKDOWN)

ETM

run the job or job step

ETM

LUS(BREAKDOWN)

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International Computers Ltd 1999Slide Slide 1515

ETM outputETM output

• Formatted to the journal– similar to LUS

• CSV format– To the job journal– To a system journal

F E E T O N T H E G R O U N D

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International Computers Ltd 1999Slide Slide 1616

ETM outputETM output

Time Elapsed Ocp OcpRTMillisecs 315906 1800 1851

Reason Pub-Int Vsi Long-S Pub-Flag Loc-Evnt Glo-Flag(IO) (Fetch-t) (Input)

Time 566 45 313587 15 0 0Cnt 53 2 7 1 0 0

You can have it formatted to the journal

F E E T O N T H E G R O U N D

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International Computers Ltd 1999Slide Slide 1717

ETM outputETM output

• CSV format

• Far better– Direct a message type to a public journal– central place where all performance information is

recorded– Additional Disc information

• Disc xfers• Tape xfers• Catalogue xfers• Dynamic extension xfers• Public xfers• Local xfers

F E E T O N T H E G R O U N D

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International Computers Ltd 1999Slide Slide 1818

Additional information in CSV formatAdditional information in CSV format

• Disc xfers The total number of Disc IO’s performed by the VM.

• Tape xfers The total number of Tape IO’s performed by the VM.

• File org xfers IO’s for dynamic extension, file attachment and detachment, file creation and deletion

• Publix xfers xfers to public journals, libraries on public library list, xfers on public connections, message text files accessed via public jnl mechanism

• Local xfers Library controller index xfers, cathan, loader, Wip store

• Catalogue read xfers Physical reads on catalogue, exclude cached xfers

• Catalogue write xfers Physical writes to catalogue

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International Computers Ltd 1999Slide Slide 1919

Why CSV?Why CSV?

• Excel– Numerous analysis tools, the two I like are:

• Filter tables• high low values

F E E T O N T H E G R O U N D

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International Computers Ltd 1999Slide Slide 2020

High Low valuesHigh Low values

27/06/97 19:12:00

27/06/97 21:36:00

28/06/97 00:00:00

28/06/97 02:24:00

28/06/97 04:48:00

28/06/97 07:12:00

28/06/97 09:36:00

28/06/97 12:00:00

F E E T O N T H E G R O U N D

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International Computers Ltd 1999Slide Slide 2121

Filter TablesFilter Tables

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International Computers Ltd 1999Slide Slide 2222

ETMETM

• How is it available?– Not part of standard product– Talk to account support