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IBM eServerJ iSeriesJ
8 Copyright IBM Corporation, 2003. All Rights Reserved.This publication may refer to products that are not currently available in your country. IBM makes no commitment to make available any products referred to herein.
Session:
Larry YoungrenAdam Stallman
Remote Journaling = Better Plumbing
Webcast
1
IBM eServer iSeries
© 2003 IBM Corporation
Receiver
Journal
Source System
SQL Table
Remote Receiver
Target System
HSL
Applications
Remote Journal
2
IBM eServer iSeries
© 2003 IBM Corporation
Receiver
Journal
Remote Journal
SQL Table
Replicated SQL Table
Remote Receiver
Target SystemHa
rves
t
Applications
Source System
HA VendorReplay
Software
Continuous HA recovery
4
IBM eServer iSeries
© 2003 IBM Corporation
Receiver
Journal
Source System
SQL Table
SQL Table
Remote Receiver
Target System
Harv
est
Applications
Role Swap
HA Vendor Software
Remote Journal
5
IBM eServer iSeries
© 2003 IBM Corporation
Receiver
Journal
Source System
SQL Table
SQL Table
Remote Receiver
Target System
Harv
est
Applications
Role Swap
Remote Journal
Delta
Why the extra Journal on
the Target ?
6
IBM eServer iSeries
© 2003 IBM Corporation
Receiver
Journal
Source System
SQL Table
ReplicaSQL Table
BP Software
M I Boundary
Target System
Send
Applications
W/o Remote
Journaling
Harv
est
Log Space
Pre-RJ use of HA BP software for Harvesting on Source
8
IBM eServer iSeries
© 2003 IBM Corporation
Primary System Backup System
MI
Apps RCVJRNE job
Exit program
Target job
Apply job
Replicated DB files
Log space
DB files JRN
Communications transport
Send entry
Receive entry
JRNReceiver
Vintage approach
9
IBM eServer iSeries
© 2003 IBM Corporation
Primary System Backup System
MI
Apps Apply job
Replicated DB files
DB files JRN
Communications transport
Receive entry
RCVJRNE job
RemoteJRN
JRNReceiver
JRNReceiver
RJ-enabled approach
10
IBM eServer iSeries
© 2003 IBM Corporation
Less CPU overhead than prior support
Shifts work to the backup/target machine Frees up CPU cycles on production/source machine
Puts packets on the wire faster
More efficient transport mechanism
Microcode to microcode transport (below MI)
Memory to memory transfer
DB images can be sent to target machine in real time
How Does Remote Jrn Differ From Prior HA Support?
11
IBM eServer iSeries
© 2003 IBM Corporation
Lakeview Technologies (MIMIX)
Vision Solutions (OMS)
Data Mirror Corp. (iCluster)
Maximum Availability (*NoMax)
iTERA (Echo2)
IBM's Data_Propagator product (for Data Warehousing)
Others pursing independent solutions for smaller shops
e.g. Sloan's TAA tools from Barsa Consulting
Traditional HA BP's(offer both RJ and non-RJ versions)
Employ Pure Remote Journal
Data Replication players
13
IBM eServer iSeries
© 2003 IBM Corporation
An enabler
New plumbing for HA Vendor products NOT a replacement for HA Vendor products !
Someone still needs to replay the resulting remote Journal entries
What is Remote Journal?
14
IBM eServer iSeries
© 2003 IBM Corporation
No application changes required
The building blocks:
Can code to APIs
Can use CL Commands HA Vendor products will often orchestrate these steps for you
How Do I Set It Up?
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IBM eServer iSeries
© 2003 IBM Corporation
Three CL Commands
Add Rmt Jrn
Rmv Rmt Jrn
Chg Rmt Jrn
CL Commands
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IBM eServer iSeries
© 2003 IBM Corporation
ADDRMTJRN RDB(JOSNA) SRCJRN(TESTRJ/J1) TGTJRN(*SRCJRN) RMTRCVLIB(*SRCRCVLIB) RMTJRNTYPE(*TYPE1) MSGQ(QSYSOPR) DLTRCV(*NO)
CHGRMTJRN RDB(JOSNA) SRCJRN(TESTRJ/J1) TGTJRN(*SRCJRN) JRNSTATE(*ACTIVE) DELIVERY(*SYNC)STRJRNRCV(*ATTACHED)
Notice that you drive the whole shebang from the production sys
Examples
Defining the Target
The Handshake
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IBM eServer iSeries
© 2003 IBM Corporation
So.. I've got two separate
Journals on my Target machine ? (both a Rmt Jrn
and a regular/local Jrn). How can I keep from getting
confused ?
19
IBM eServer iSeries
© 2003 IBM Corporation
Redirection: Using an Alt Lib
Comm Line
Remote Receiver
ALT_Lib
RJ:Redirected
Library New
Journal
Source System
SQL Table
Receiver
REG_Lib
Target System
Local Receiver
Target System
SQL Table
Replica
REG_Lib
20
IBM eServer iSeries
© 2003 IBM Corporation
How do you redirect a remote journal ?
1. On target: CRTLIB LIB(ALT_LIB)2. ADDRDBDIRE RDB(RDBNAME) RMTLOCNAME(SYSTEM *IP)
where RDBNAME matches the *LOCAL RDB Entry on the Target and SYSTEM matches the Target's System Name or IP address
3. ADDRMTJRN RDB(RDBNAME) SRCJRN(REG_LIB/J1) TGTJRN(ALT_LIB/J1) RMTRCVLIB(ALT_LIB)
This command will create the remote journal in the Alternative (Redirected) library ALT_LIB on the target system.
4. CHGRMTJRN RDB(RDBNAME) SRCJRN(REG_LIB/J1) TGTJRN(ALT_LIB/J1) JRNSTATE(*ACTIVE)
This command will activate remote journal and create the journal receiver in library ALT_LIB on the target system.
Redirecting a Remote Journal
This will be your redirected (alternative) Library
Ahh... Name conflict resolution through
redirection !
21
IBM eServer iSeries
© 2003 IBM Corporation
Three primary APIs
QJO Add Remote Journal
QJO Remove Remote Journal
QJO Change Journal State
Coding examples at:
http://www.as400.ibm.com/db2/db2code.htm
API Interfaces
Any coding examples ?
22
IBM eServer iSeries
© 2003 IBM Corporation
WRKJRNA - F16 Work with Remote Journal Information Journal . . . . . . : J1 Library . . . . . . : TESTRJ Journal type . . . . : *LOCAL Journal state . . . : *ACTIVE Remote journal type : Delivery mode . . . : Local journal . . . : Source journal . . . : Library . . . . . : Library . . . . . : ASP group . . . . : ASP group . . . . : System . . . . . . : System . . . . . . : Redirected receiver library . . . . . . . . . . . . . . . . . : *NONE Number of remote journals . . . . . . . . . . . . . . . . . . : 1 Type options, press Enter. 13=Activate 14=Inactivate ...
--------------------Remote-------------------- Relational Journal Delivery Opt Database Journal Library State Mode SYSTEM1 J1 TESTRJ *INACTIVE Bottom ===> F3=Exit F4=Prompt F5=Refresh F6=Work with remote journal list
F9=Retrieve F12=Cancel F23=More options
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IBM eServer iSeries
© 2003 IBM Corporation
Rmt Jrn uses RDB (Relational Database) entries to locate the remote systems
ADDRDBDIRE RDB(RDBNAME) RMTLOCNAME(SYSTEM *IP) Where RDBNAME matches the *LOCAL RDB Entry on the Target and SYSTEM matches the Target System's Name or IP address
Identifying the target machine So that's how Rmt
Jrn figures out which remote
machine to use !
25
IBM eServer iSeries
© 2003 IBM Corporation
Six transport mechanisms: Opticonnect (Optical bus) Virtual (LPAR to LPAR) opticonnect TCP/IP SNA (APPC) ATM HSL
Chapter 6 of Journal Performance Redbook documents the most recent Remote Journal speeds over various communication lines
What Communication connections can I use ?
Everything but a tin can and a string
26
IBM eServer iSeries
© 2003 IBM Corporation
Two Redbooks: Original Remote Journal Redbook:
AS/400 Remote Journal Function for High Availability and Data Replication
Found at www.ibm.com/redbooks Striving For Optimal Journal Performance
Remote Journal speeds in Chapter 6
Recent Magazine Articles: Eight "Tips" for Optimal Journal Performance
Jan and Feb '03 issues of iSeries News
ISeries Information Center: Found at www.ibm.com/eserver/iseries/infocenter
Resources
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IBM eServer iSeries
© 2003 IBM Corporation
Source Sys Target 2
Target 255
Target 1
Broadcast mode of Remote Journal
Can broadcast to up to 255 secondaries/targets
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IBM eServer iSeries
© 2003 IBM Corporation
Source Sys 1
Hub
Employing a centralized Regional Hub
Source Sys 2
Source Sys 3
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IBM eServer iSeries
© 2003 IBM Corporation
Source Sys
Second Target
First Target
Sync
Async
Cascade mode of Remote Jrn
Can cascade without limit
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IBM eServer iSeries
© 2003 IBM Corporation
Receiver
Journal
Source System
SQL Table
Remote Receiver
Target System
SLIC Async Sending Task
Async Remote
Journaling
Applications
Async Remote Journal Your
application doesn't wait
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IBM eServer iSeries
© 2003 IBM Corporation
Receiver
Journal
Remote Journal
SQL Table
Remote Receiver
Applications
Acknowledgment response
Target SystemSource System
Sync Remote Journal Your application pauses until the
response is received
34
IBM eServer iSeries
© 2003 IBM Corporation
Sync mode
Big advantage: no trapped transactions All Journal entries reach the target system in real time
JRN image reaches target machine BEFORE reaching disk of source
Especially practical with Virtual OptiConnect, HSL, and high-speed ATM Most practical over short distances
Bene: No commit transactions are viewed as complete by your customer, then rolled back by your Take-over (target) machine !
Pros and Cons of Sync vs Async mode
Sync Async
35
IBM eServer iSeries
© 2003 IBM Corporation
Async mode
Advantage: slightly less performance overheadProbably good choice for heavy batch jobs or slow communication linesCustomary choice when source and target machines are separated by substantial distances
Drawback: some risk of lost/trapped recent transactions not sent acrossSame kinds of risks as vintage async Business Partner solutionsIn-house for slow lines we've seen up to 1.5 sec latency
But only 5 Msec latency for virtual Opti-connect and HSL
Drawback: Probably tougher to recalibrate after a fail-over
Pros and Cons of Sync vs Async mode
Sync Async
Traffic Jam possible
36
IBM eServer iSeries
© 2003 IBM Corporation
Ok, I see the HA benefit of Rmt Jrn.
But... what else can I do with this
technology ?
37
IBM eServer iSeries
© 2003 IBM Corporation
Receiver
Journal
Remote Journal
SQL Table
Target System
Remote Receiver
Applications
Source System
Alternative Rmt Jrn uses: Alternative #1 A remote Vault
Remote system:Less expensive.Head to Hot Site w/ tapes
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IBM eServer iSeries
© 2003 IBM Corporation
Production System
...
Alternate System
...
Remote Journal Connection
Saving from an alternate system reduces the impact on the production system. This also allows you to always have access to the latest changes to apply even if you haven't saved your Journal Receivers lately!
PF's
(large system $$$$$) (smaller system $)
(just the delta)
Off-Site Vaulting Example
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IBM eServer iSeries
© 2003 IBM Corporation
Receiver
Journal
Remote Journal
SQL Table
Data Warehouse
Target System
Harv
est
Remote Receiver
Applications
Source System
Alternative Rmt Jrn uses: Alternative #2Refresh a Data
Warehouse
Data Propagator
41
IBM eServer iSeries
© 2003 IBM Corporation
Receiver
Journal
SQL Table
Target System
Remote Receiver
Remote Journal
Applications
Source System
Replaying from a Rmt JrnAlternative #3
Warm Site Hourly refresh
Replicated critical files
Local Receiver
ApyJ
rnCh
gX
Replay Step
How are you going to make the Rmt Jrn look like a "Local"
Jrn ?
42
IBM eServer iSeries
© 2003 IBM Corporation
Rest
ore
Remote Receiver
Target System
Replaying from a Rmt JrnFooling Journal into thinking the
Rmt Jrn is a "Local"
Replicated critical files
Local Receiver
ApyJ
rnCh
gX
Save_File
43
IBM eServer iSeries
© 2003 IBM Corporation
Can I APYJRNCHG from a Remote Journal Receiver ?
See online magazine article:MC Press online
1/21/03Remote Journaling and Data Recovery
by Chris Hird
Yes !
44
IBM eServer iSeries
© 2003 IBM Corporation
Got any suggestions regarding how to
make Rmt Jrn have minimal overhead ?
45
IBM eServer iSeries
© 2003 IBM Corporation
Remote Journal Performance Considerations
Larry Youngren
46
IBM eServer iSeries
© 2003 IBM Corporation
Receiver
Journal
Source System
SQL Table
SQL Table
Remote Receiver
Target System
Harv
est
Catch-up phaseDelta
Delta
Swap Back to Production
HA Vendor Software
48
IBM eServer iSeries
© 2003 IBM Corporation
The secrets of optimal Rmt Jrn performance
Watch that pesky extra
journal on the target machine
49
IBM eServer iSeries
© 2003 IBM Corporation
Performance tuning on the Target side
Target SystemSource System
50
IBM eServer iSeries
© 2003 IBM Corporation
Speeding up Target side Remote Journal via Journal Caching
Secret #1
51
IBM eServer iSeries
© 2003 IBM Corporation
User ASP
10
PF 3
Journal Bundling
Main Memory Buffer
IOA
Write Cache
128K Buffer
HA Replay Job #1
HA Replay Job #2
HA Replay Job #3
PF 1 PF 2
Journal Receiver
Journal
Known as a journal "Bundle"
Main Memory Journal Caching
Delta
52
IBM eServer iSeries
© 2003 IBM Corporation
Trgt Jrn/ BP Async RJ Jrn Cache0
100200300400500600700800900
Thou
sand
sQ
ty tr
ansa
ctio
ns u
napp
lied
on T
arge
t
Shows worst case backlog unapplied on Target
Retail store Target backlogTeraplex model 840 w/ 11-CPU partition
HA BP software harvesting on Source vs. Rmt Jrn
Conclusion: Use of the Journal Caching PRPQ (5799-BJC) on the target machine helps HA Vendor replay software from falling behind during especially aggressive journal-intensive processing such as batch jobs.
290
793,601
565,518
Best case for Replay Only 0.1 Sec behind.
How far "behind" are the replay jobs on the Target ?
The Caching approach
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IBM eServer iSeries
© 2003 IBM Corporation
Potential Performance Benefits of Journal Caching
(For Target Machine's Keep-up Mode)
Apply rate on Target machine
Before Caching 600,000 transactions/Hr
With Caching on target 2,400,000 transactions/Hr
Source System
Target System
JrnCache(*Yes)
54
IBM eServer iSeries
© 2003 IBM Corporation
Target machine suggestions:
Software (Journal) Caching
Enable Journal Caching on the Target machine
Elbow Room
Assure base pool on Target machine has enough elbow roomAt least 10 Meg for catch-up/reconnect phase per RJ connection
Sufficient Disk arms
Assure ASP housing target receiver has at least as many disk arms as matching receiver from the source system
Write cache
Configure lots of IOA write cache - - especially on the target machine
Choices: 26 Meg 104 Meg 757 Meg
What Else Can I Do To Speed It Up?
Newest
55
IBM eServer iSeries
© 2003 IBM Corporation
Receiver
Journal
Need enough Arms
Write Cache
. . .
IOP 104 Meg of Write
Cache(older vintage IOPs
have less)
Don't skimp on the write cache Model Write Cache
(older) 2763 10 MegNEW !! 2782 40 Meg
(older) 2778 26 (104) MegNEW !! 2757 235 (757) Meg
Feb '03
Up to 1 Million Jrn Ents/Minute
56
IBM eServer iSeries
© 2003 IBM Corporation
Have you got sufficient IOA Write cache ?
See Appendix "A"
Shows algorithm/Query to analyze write cache overflow
Found at www.ibm.com/redbooks
57
IBM eServer iSeries
© 2003 IBM Corporation
Speeding up Remote Journal via Standby mode
Secret #2V5R2!
58
IBM eServer iSeries
© 2003 IBM Corporation
Receiver
Journal
Remote Journal
SQL Table
SQL Table
HA vendor Software
Remote Receiver
Target System
Harv
est
Source System
Standby mode
CHGJRN... JRNSTATE(*STANDBY)
Standby mode
V5R2!
59
IBM eServer iSeries
© 2003 IBM Corporation
Role Swap:
Receiver
Journal
Source System
ReplicatedSQL Table
HA Vendor Software
Active mode
Target System
Harv
est
Applications
Remote Receiver
Becomes Active
Switching out of Standby mode
CHGJRN ... JRNSTATE(*ACTIVE)
Delta
60
IBM eServer iSeries
© 2003 IBM Corporation
BP/Trgt Jrn Async RJ Standby0
100200300400500600700800900
Thou
sand
sQ
ty tr
ansa
ctio
ns u
napp
lied
on T
arge
t
Shows worst case backlog unapplied on Target
Retail store backlog on Target Teraplex model 840 w/ 11-CPU partition
HA BP software harvesting on Source vs. Rmt Jrn793,601
Standby Mode
How far "behind" are the replay jobs on the Target ?
588
565,518
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IBM eServer iSeries
© 2003 IBM Corporation
Potential Standby mode Benefit:
Very little performance overhead on the target machine while in standby mode
Much more rapid failover in the event of a failureOS/400 merely flips one flag in the Journal rather than writing to disk thousands
of Database file headers
Mode transition rates during Role-swap as fast as...
How long does it take to re-enable Journaling on the Target during a
Role-swap ?
62
IBM eServer iSeries
© 2003 IBM Corporation
10,000 files 25,000 files0
500
1000
1500
2000
2500
Seco
nds
Start Journaling (STRJRNPF) Standby to Active Transition(CHGJRN)
Start Journal vs. Standby to Active Transition
The V5R2 advantage
Role-Swap on the Target
V5R2!
63
IBM eServer iSeries
© 2003 IBM Corporation
Summary
Net:
Order & Install Option 42
Option 42 encompasses both: JrnCache(*Yes) JrnState(*Standby)
V5R2!
64
IBM eServer iSeries
© 2003 IBM Corporation
Performance tuning on the Source side
Target SystemSource System
65
IBM eServer iSeries
© 2003 IBM Corporation
Sending fewer bytes down the communication line(withholding the hidden entries)
Secret #3
66
IBM eServer iSeries
© 2003 IBM Corporation
Main Memory
Journal Entry
AP
Journal Entry
PF
Write Cache
IOP2
Write Cache
IOP1
Hidden Jrn entries
Overlapped writes with CHGJRN ... RcvSizOpt(*RMVINTENT)
JOE
AP
User ASPOnly these must be
sent via RJ
. .
.JOE
PF
67
IBM eServer iSeries
© 2003 IBM Corporation
Reduce the fixed overhead per Journal Entry(Sending only the data)
Secret #4
68
IBM eServer iSeries
© 2003 IBM Corporation
Change Journal (CHGJRN) Type choices, press Enter. Journal . . . . . . . . . . . . > JRN1 Name Library . . . . . . . . . . . > JRNLIB Name, *LIBL, *CURLIB Journal receiver: Journal receiver . . . . . . . > *GEN Name, *SAME, *GEN Library . . . . . . . . . . Name, *LIBL, *CURLIB Receiver size options . . . . . *SAME *SAME, *NONE, *RMVINTENT... + for more values Minimize entry specific data . . *SAME *SAME, *NONE, *FILE, *DTAARA Journal caching . . . . . . . . *SAME *SAME, *NO, *YES Fixed length data . . . . . . . > *JOB *JOBUSRPGM, *JOB, *USR... > *USR > *PGM _ > *SYSSEQ + for more values > *THD Text 'description' . . . . . . . *SAME More...F3=Exit F4=Prompt F5=Refresh F12=Cancel F13=How to use this display F24=More keys
CHGJRN command with new FIXLENDTA parm
Customizing what we collect
V5R2!
69
IBM eServer iSeries
© 2003 IBM Corporation
Summary
Be Selective:
Use the Goldilocks principle...
Advise us to collect only what you truly need, no more and no less
70
IBM eServer iSeries
© 2003 IBM Corporation
Sending fewer bytes down the communication line(Sending only the delta)
Secret #5
71
IBM eServer iSeries
© 2003 IBM Corporation
A new parameter (MINENTDTA) is provided to allow specifying which object types are allowed to minimize their journal entries.
Specified on: CRTJRN - Create Journal
CHGJRN - Change Journal
Journaling Minimal Data
72
IBM eServer iSeries
© 2003 IBM Corporation
Journal Minimal Data is provided for Database Updates
With Journal Minimal Data enabled only the essential changed bytes are written to the journal (not the whole record image).
This can lead to:Reduction in the size of journal receiversSending minimized journal entries remotely for object replication will also reduce comm line traffic.
Journaling Minimal Data
The Remote Jrn advantage
73
IBM eServer iSeries
© 2003 IBM Corporation
Interactive Job Batch Job
Reduction of Journal Receiver size
40% fewer bytes generated
60% fewer bytes generated
Performance consequences
4.6% more thruput,3.5% less CPU
3% reduction in batch run time
ESP Customer in Netherlands reported similar results
In-house measurement
74
IBM eServer iSeries
© 2003 IBM Corporation
On the Target System:
Use Journal Caching CHGJRN ... JrnCache(*Yes)
Consider use of Journal Standby mode CHGJRN ... JrnState(*Standby)
On the Source System:
Employ CHGJRN ... RcvSizOpt(*RmvIntEnt)Puts a "fork" in the roadInhibits sending Access Path journal images to target system Do this only if you have more than one disk arm in your User ASP
Consider use of Journal-Minimal Data CHGJRN ... MinEntDta(*File)
Reduces quantity of traffic across the communication line Speeds up Re-play processing by HA vendor software
Consider use of MINFIXLEN or FIXLENDTA settings
Summary: Secrets to Good Rmt Jrn performance
75
IBM eServerJ iSeriesJ
8 Copyright IBM Corporation, 2003. All Rights Reserved.This publication may refer to products that are not currently available in your country. IBM makes no commitment to make available any products referred to herein.
Session:
Larry YoungrenAdam Stallman
Remote Journaling = Better Plumbing
Webcast
76
IBM eServer iSeries
© 2003 IBM Corporation
Trademarks and Disclaimers
8 IBM Corporation 1994-2003. All rights reserved.References in this document to IBM products or services do not imply that IBM intends to make them available in every country.
The following terms are trademarks or registered trademarks of International Business Machines Corporation in the United States, other countries, or both:
Other company, product or service names may be trademarks or service marks of others.
Information is provided "AS IS" without warranty of any kind.
All customer examples described are presented as illustrations of how those customers have used IBM products and the results they may have achieved. Actual environmental costs and performance characteristics may vary by customer.
Information in this presentation concerning non-IBM products was obtained from a supplier of these products, published announcement material, or other publicly available sources and does not constitute an endorsement of such products by IBM. Sources for non-IBM list prices and performance numbers are taken from publicly available information, including vendor announcements and vendor worldwide homepages. IBM has not tested these products and cannot confirm the accuracy of performance, capability, or any other claims related to non-IBM products. Questions on the capability of non-IBM products should be addressed to the supplier of those products.
All statements regarding IBM future direction and intent are subject to change or withdrawal without notice, and represent goals and objectives only. Contact your local IBM office or IBM authorized reseller for the full text of the specific Statement of Direction.
Some information in this presentation addresses anticipated future capabilities. Such information is not intended as a definitive statement of a commitment to specific levels of performance, function or delivery schedules with respect to any future products. Such commitments are only made in IBM product announcements. The information is presented here to communicate IBM's current investment and development activities as a good faith effort to help with our customers' future planning.
Performance is based on measurements and projections using standard IBM benchmarks in a controlled environment. The actual throughput or performance that any user will experience will vary depending upon considerations such as the amount of multiprogramming in the user's job stream, the I/O configuration, the storage configuration, and the workload processed. Therefore, no assurance can be given that an individual user will achieve throughput or performance improvements equivalent to the ratios stated here.
AS/400 IBMAS/400e IBM (logo)eServer iSeries
OS/400
77