Transcript zAAP-eligible work

Introduction to zAAP
(zSeries Application Assist Processor)
Don Deese
Computer Management Sciences, Inc.
www.cpexpert.com
All trademarks are the property of their respective owners.
©Copyright 2004, Computer Management Sciences, Inc., Alexandria, VA
www.cpexpert.com
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Presentation Outline
Overview of zAAP (IFA) Processor
Benefits and requirements of zAAP
Description of how zAAP works
User controls for zAAP processing
Performance considerations with zAAP
Data available to measure zAAP performance
Conclusions and references
NOTE:
zAAP operates only in a PR/SM environment. All references to “central processor” or “zAAP/IFA
processor” should be taken to mean “logical central processor” and “logical zAAP/IFA processor”.
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What is zAAP (IFA) Processor
“Special processor” available with z890, z990, z9.
Called either zAAP or IFA (Integrated Facility for
Applications) depending on IBM document.
Runs only JAVA work (zAAP-eligible work) under
control of JVM.
Similar to IFL (Integrated Facility for Linux).
Does not increase MSU rating of z890, z990, or z9.
Purchase and maintenance cost are significantly
lower than with standard central processor.
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Z990 Processor Units – sample definition
PU
CP
PU
CP
PU
PU
CP
PU
PU
PU
PU
SAP
ICF
CP
spare
spare
IFL
IFA
Special processors
Central processors (CP)
Special processors
SAP
SAP
System Assist Processor
ICF
Internal Coupling Facility
IFL
Integrated Facility for Linux
IFA
Integrated Facility for Applications
PU
Unused
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Z890 Processor Units – sample definition
PU
PU
CP
CP
PU
IFA
Central processors (CP)
z890
PU
#CP #IFA
61nn
1
1
62nn
2
2
63nn
3
1
64nn
4
0
SAP
IFA
Special processors
SAP
System Assist Processor
IFA
Integrated Facility for Applications
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Benefits of zAAP Processors
Attractively priced ($125K USD per zAAP engine).
IBM zSeries software charges are unaffected (MSU rating
is unchanged when zAAP is added).
Can run JAVA work on zAAP attached to z890 (zAAP runs
at full speed, while z890 CPs can run at potentially much
lower sub-capacity speed).
Sub-capacity IBM software charges could be reduced.
Significantly lower maintenance costs than standard CPs.
Up to one zAAP processor per central processor in a CPC.
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Limitations of zAAP processors
Available only with z890 and z990 (and above)
Only one zAAP per purchased central processor
Cannot execute user instructions (other than under
control of JVM)
Does not processes I/O interrupts
With z890/z990, zAAP inherits LPAR attributes from
LPAR definition
Does not participate in IRD management and retains
initial LPAR weight even if WLM changes LPAR weight
Does not support WLM soft-capping (meaningless
since IFA is not reflected in defined capacity)
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How does zAAP (IFA) work?
zAAP-eligible work must be processed in LPAR with
one or more normal CPs
JVM decides whether JAVA work is zAAP-eligible.
JVM notifies z/OS dispatcher that zAAP-eligible work is
ready to execute
zAAP-eligible work is dispatched to IFA (or to CP).
User specifications control whether zAAP-eligible work
executes on IFA and on CP, or executes only on IFA.
User specifications control whether zAAP-eligible work
executes in competition with normal “goal” work.
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Example flow when JAVA work is executed on IFA
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zAAP External Controls in IEAOPTxx
IFACROSSOVER
 With z/OS V1R6, specifies whether zAAP-eligible work
can “cross over” to run on CP as well as on IFA.
 Meaning and importance changes with z/OS V1R7.
IFAHONORPRIORITY
 Specifies whether zAAP-eligible work and other work
will be dispatched to both CP and IFA based on WLMassigned priority.
 zAAP-eligible work will always be dispatched on IFA
based on WLM-assigned priority.
 If zAAP-eligible work runs on CP below DISC priority,
zAAP-eligible work will be dispatched based on WLMassigned priority for the zAAP-eligible work.
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zAAP Controls with z/OS V1R6
IFACROSSOVER and IFAHONORPRIORITY
But see OA14131 (applies z/OS V1R7 changes)
X-OVER
HON-PRI
Meaning
YES
YES
Dispatch zAAP-eligible work to both
CP and IFA, in dispatching priority
order. Soft-capping in effect  dispatch
at priority below discretionary.
YES
NO
Dispatch zAAP-eligible work to IFA
and dispatch to CP below
discretionary.
NO
N/A
Dispatch zAAP-eligible work only to
IFA. If no available IFA  dispatch to CP
at priority below discretionary.
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zAAP Controls with z/OS V1R7
IFAHONORPRIORITY, AWM, and IFACROSSOVER
Meaning
HON-PRI AWM X-OVER
YES
YES
N/A
Dispatch zAAP-eligible work to both CP
and IFA, in dispatching priority order.
Soft-capping in effect  dispatch to CP at
priority below DISC. But see OA13953!
YES
NO
YES
Dispatch zAAP-eligible work to IFA and
dispatch to CP below DISC.
YES
NO
NO
Run zAAP-eligible work on CP only if
no IFA in LPAR.
NO
N/A
YES
Dispatch zAAP-eligible work to IFA and
dispatch to CP below DISC.
NO
N/A
NO
Run zAAP-eligible work on CP only if
no IFA in LPAR.
AWM = Alternate Wait State Management
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Sample z/OS Dispatching
IFACROSSOVER=YES (with z/OS V1R6)
AWM decides IFA “needs help” (with z/OS V1R7)
IFAHONORPRIORITY=YES
WORK UNIT
PRIORITY
WORK UNIT
PRIORITY
Goal, not zAAP #5
243
zAAP-eligible #4
249
Goal, not zAAP #2
241
zAAP-eligible #3
247
Goal, not zAAP #4
239
zAAP-eligible #5
245
DISCR, not zAAP #1
192
zAAP-eligible #2
241
SYSTEM DISPATCH QUEUE
IFA DISPATCH QUEUE
z/OS Dispatcher selects “zAAP-eligible #4” for dispatch,
since it is the highest priority.
If IFA available, dispatch to IFA.
If IFA not available, dispatch to CP.
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Sample z/OS Dispatching
IFACROSSOVER=YES
IFAHONORPRIORITY=NO
WORK UNIT
PRIORITY
WORK UNIT
PRIORITY
Goal, not zAAP #5
243
zAAP-eligible #4
178
Goal, not zAAP #2
241
zAAP-eligible #3
176
Goal, not zAAP #4
239
zAAP-eligible #5
174
DISCR, not zAAP #1
192
zAAP-eligible #2
172
SYSTEM DISPATCH QUEUE
IFA DISPATCH QUEUE
If IFA available, z/OS Dispatcher selects “zAAPeligible #4”for dispatch, since it is highest priority.
z/OS Dispatcher selects “zAAP-eligible #4” for
dispatch on CP below DISC.
.
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Sample z/OS Dispatching
IFACROSSOVER=NO
IFAHONORPRIORITY=NO
WORK UNIT
PRIORITY
WORK UNIT
PRIORITY
Goal, not zAAP #5
243
zAAP-eligible #4
178
Goal, not zAAP #2
241
zAAP-eligible #3
176
Goal, not zAAP #4
239
zAAP-eligible #5
174
DISCR, not zAAP #1
192
zAAP-eligible #2
172
SYSTEM DISPATCH QUEUE
IFA DISPATCH QUEUE
If IFA available, z/OS Dispatcher selects “zAAPeligible #4”for dispatch, since it is highest priority.
z/OS Dispatcher will select “zAAP-eligible #4” for
dispatch on CP only if no IFA in LPAR.
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zAAP Performance considerations
z/OS V1R6 and z890/z990
Large number of central processors versus zAAP
processors defined to LPAR
High Goal Importance of zAAP-eligible work
Low Goal Importance of zAAP-eligible work
High CPU activity level of central processors
With z890/z990, LPAR definitions could conflict with
LPAR definitions for other shared special processors
in “Pool 2”. Problem solved with z9 109.
PR/SM Logical to Physical processor ratio
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Performance consideration with zAAP, z/OS V1R6
IFACROSSOVER=YES
IFAHONORPRIORITY=YES
WORK UNIT
PRIORITY
WORK UNIT
PRIORITY
Goal, not zAAP #5
243
zAAP-eligible #4
249
Goal, not zAAP #2
241
zAAP-eligible #3
247
Goal, not zAAP #4
239
zAAP-eligible #5
245
DISCR, not zAAP #1
192
zAAP-eligible #2
241
SYSTEM DISPATCH QUEUE
IFA DISPATCH QUEUE
z/OS Dispatcher selects “zAAP-eligible #4” for dispatch.
If IFA available, dispatch to IFA.
If IFA not available, dispatch to CP.
With large number of logical CPs, zAAP-eligible work
will tend to be done by CPs, rather than by IFA.
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Performance consideration with zAAP, z/OS V1R6
IFACROSSOVER=YES
IFAHONORPRIORITY=YES
WORK UNIT
PRIORITY
WORK UNIT
PRIORITY
Goal, not zAAP #5
243
zAAP-eligible #4
249
Goal, not zAAP #2
241
zAAP-eligible #3
247
Goal, not zAAP #4
239
zAAP-eligible #5
245
DISCR, not zAAP #1
192
zAAP-eligible #2
241
SYSTEM DISPATCH QUEUE
IFA DISPATCH QUEUE
z/OS Dispatcher selects “zAAP-eligible #4” for dispatch.
If IFA available, dispatch to IFA.
If IFA not available, dispatch to CP.
With high Goal Importance, zAAP-eligible work will
tend to be done by CPs, rather than by IFA.
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Performance consideration with zAAP, z/OS V1R6
IFACROSSOVER=YES
IFAHONORPRIORITY=YES
WORK UNIT
PRIORITY
WORK UNIT
PRIORITY
Goal, not zAAP #5
243
zAAP-eligible #4
237
Goal, not zAAP #2
241
zAAP-eligible #3
235
Goal, not zAAP #4
239
zAAP-eligible #5
233
DISCR, not zAAP #1
192
zAAP-eligible #2
231
SYSTEM DISPATCH QUEUE
IFA DISPATCH QUEUE
z/OS Dispatcher selects “zAAP-eligible #4” for dispatch.
If IFA available, dispatch to IFA.
If IFA not available, dispatch to CP.
With low Goal Importance, zAAP-eligible work will
tend to be done only by IFAs, which could imply that
more zAAP processors are needed than expected.
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Performance consideration with zAAP, z/OS V1R6
IFACROSSOVER=NO
IFAHONORPRIORITY=not applicable
WORK UNIT
PRIORITY
WORK UNIT
PRIORITY
Goal, not zAAP #5
243
zAAP-eligible #4
178
Goal, not zAAP #2
241
zAAP-eligible #3
176
Goal, not zAAP #4
239
zAAP-eligible #5
174
DISCR, not zAAP #1
192
zAAP-eligible #2
172
SYSTEM DISPATCH QUEUE
IFA DISPATCH QUEUE
If IFA available, z/OS Dispatcher on IFA selects “zAAPeligible #4”for dispatch.
z/OS Dispatcher on CP selects “zAAP-eligible #4” for
dispatch only after “DISCR, not zAAP #1” dispatched.
If small number of IFAs defined to LPAR, zAAPeligible work will tend to be delayed waiting on IFA.
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Performance consideration with zAAP on z890/z990
LPAR Definitions
CP
CP
CP
ICF
CP
Central processors (CP)
LPAR
Dedicated
WEIGHT SHARE LCP IFA
LPAR
IFL
IFA
Special processors (SP)
WEIGHT SHARE LSP
%SP
SYSA
50
5.0%
1
0
LINUX1
10
50.0%
1
50.0%
SYSB
200
20.0%
2
0
LINUX2
10
50.0%
1
50.0%
SYSC
200
20.0%
2
0
TOTAL
20
100.0%
SYSD
400
40.0%
3
0
Before IFA
SYSE
150
15.0%
2
1
LPAR
TOTAL
1000
100.0%
10
LCP = Logical Central Processor
LSP = Logical Special Processor
100.0%
WEIGHT SHARE LSP
%SP
LINUX1
10
5.9%
1
11.8%
LINUX2
10
5.9%
1
11.8%
SYSE
150
88.2%
1
176.5%
TOTAL
170
100.0%
200.0%
After IFA (Example only. SYSE cannot really
have over 100% as only 1 IFA assigned to SYSE.)
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Performance consideration with zAAP on z890/z990
LPAR Definitions
CP
CP
CP
CP
ICF
Central processors (CP)
LPAR
Dedicated
IFL
IFA
Special processors (SP)
WEIGHT SHARE LCP IFA
SYSA
50
5.0%
1
0
LPAR
SYSB
200
20.0%
2
0
LINUX1
75
25.0%
1
50%
SYSC
200
20.0%
2
0
LINUX2
75
25.0%
1
50%
SYSD
400
40.0%
3
0
SYSE
150
50.0%
1
100%
SYSE
150
15.0%
2
1
TOTAL
300
100.0%
TOTAL
1000
100.0%
10
WEIGHT SHARE LSP
%SP
200%
This situation really is no different than when adding any LPAR (except the zAAP
part is inherited from the central processor LPAR definition). You must carefully
review your weights and resulting shares considering LPARs with zAAPs.
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Performance consideration with zAAP on z890/z990
LPAR Definitions
CP
CP
CP
CP
ICF
Central processors (CP)
Dedicated
LPAR
LPAR
WEIGHT SHARE LCP IFA
SYSA
50
5.0%
1
2
SYSB
200
20.0%
2
2
SYSC
200
20.0%
2
2
SYSD
400
40.0%
3
2
SYSE
150
15.0%
2
2
TOTAL
1000
100.0%
10
10
IFL
IFA
IFA
Special processors (SP)
WEIGHT SHARE LSP
%SP
LINUX1
75
6.5%
1
19.6%
LINUX2
75
6.5%
1
19.6%
SYSA
50
4.3%
2
13.0%
SYSB
200
17.4%
2
26.1%
SYSC
200
17.4%
2
52.2%
SYSD
400
34.8%
2
52.2%
SYSE
150
13.0%
2
39.1%
TOTAL
1150
100.0%
12
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Performance consideration with zAAP on z890/z990
LPAR Definitions
CP
CP
CP
CP
ICF
Central processors (CP)
LPAR
Dedicated
IFL
IFA
IFA
Special processors (SP)
WEIGHT SHARE LCP IFA
SYSA
50
5.0%
1
2
LPAR
SYSB
200
20.0%
2
2
LINUX1
250
16.7%
1
50.0%
SYSC
200
20.0%
2
2
LINUX2
250
16.7%
1
50.0%
SYSD
400
40.0%
3
2
SYSA
50
3.3%
2
5.0%
SYSE
150
15.0%
2
2
SYSB
200
13.3%
2
20.0%
TOTAL
1000
100.0%
10
10
SYSC
200
13.3%
2
40.0%
SYSD
400
26.7%
2
40.0%
SYSE
150
10.0%
2
15.0%
TOTAL
1500
100.0%
12
• Logical to Physical ratio - 12:3 (4:1)
• IFL & IFA share comes from same pool
• Unused IFL capacity can be used for IFA
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WEIGHT SHARE LSP
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%SP
24
RMF zAAP performance data
TYPE 72 Description
R723IFAU
Samples of zAAP-eligible work using a processor.
R723IFCU
Samples of zAAP-eligible work executing on a CP.
R723IFAD
Samples of zAAP-eligible work that was delayed,
waiting for a processor.
R723IFAT
IFA processor time used by zAAP-eligible work.
R723NFFI
Normalization factor for CP versus IFA speed.
R723MFLG
Indicators of IFACROSSOVER and
IFAHONORPRIORITY specification.
R723IFCT
IFA processor time spent on normal CPs.
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Conclusions
zAAP offering appears to be an excellent way to obtain
significantly increased processor capacity at a very
attractive price.
Sufficient zAAP-eligible work must exist.
PR/SM definitions must be carefully reviewed (most problems
solved with z9 109).
Service class Performance Goals and Goal Importance must be
carefully considered.
IBM has provided sufficient RMF data for analysts to determine
IFA processor capacity requirements and performance
problems.
OW14131 and OW13953 solve many problems with z/OS V1R6.
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References
GM13-0624 – Introducing the new zSeries Application Assist Processor
SG24-6310: IBM zSeries 890 Technical Introduction
SG24-6947: IBM zSeries 990 Technical Guide
SG24-6669: IBM z9 109 Technical Introduction
SG24-6386: zSeries Application Assist Processor (zAAP) Implementation
SB10-7036-03: zSeries 890 and 990 Processor Resource/Systems Manager
Planning Guide
SG24-5922: z/OS Intelligent Resource Director
z/OS MVS Planning: Workload Management (z/OS V1R6 and z/OS V1R7)
MVS Initialization and Tuning Reference (z/OS V1R6 and z/OS V1R7)
z/OS Performance: Capacity Planning Considerations for zAAP White Paper
z990 and z890 zAAP - What it Can Do for You SHARE - Summer, 2004 MVS
SCP Project Session: 2825, Kathy Walsh (IBM Washington Systems Center,
Advanced Technical Support)
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References
IBM White Paper (WP100489) Mission: zAAP your costs, Running Websphere
and Java on the zSeries Application Assist Processor (updated)
IBM White Paper (WP100417) z/OS Performance: Capacity Planning
Considerations for zAAP Processors
IBM EXPO 2005, Session P06 z/OS Performance "HOT" Topics, Kathy Walsh
(IBM Washington Systems Center, Advanced Technical Support)
IBM EXPO 2005, Session P25 Everything zAAP, Kathy Walsh (IBM Washington
Systems Center, Advanced Technical Support)
APAR 0A14131 and APAR 0A13953
http://www-1.ibm.com/servers/eserver/zseries/zaap/gettingstarted/
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Introduction to zAAP
(zSeries Application Assist Processor)
Don Deese
Computer Management Sciences, Inc.
www.cpexpert.com
All trademarks are the property of their respective owners.
©Copyright 2004, Computer Management Sciences, Inc., Alexandria, VA
www.cpexpert.com
29
z890 Sub-capacity MSU rating
(28 capacity levels)
1-WAY MSU
4-WAY MSU
110
4
410
15
120
7
420
26
130
13
430
49
140
17
440
62
150
26
450
97
160
32
460
119
170
56
470
208
zAAP processor runs at full speed
Regardless of capacity rating!
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