Atos White Paper Mainframes in Perspective

7/27/2019 Atos White Paper Mainframes in Perspective

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Mmainframesin perspectivea classic going strongYour business technologists. Powering progress

White paper


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Contents

1. Introduction and summary 4

2. How we got here: the road less travelled 62.1. Market position 6

2.2. Availability, per ormance and utilization 6

2.3. So tware and standards 8

2.4. Cost o ownership or usage 8

2.5. The evolution o computing 8

3. How does legacy main ramet within current IT? 10

3.1. Market position 10

3.2. Availability, per ormance and utilization 12

3.3. So tware and standards 12

3.4. Speciality engines 13

3.5. Cost o ownership or usage 14

3.6. Environmental considerations 15

3.7. Main rames and Cloud Computing 15

3.8. Greying o the work orce 16

4. New developments withinthe main rame world 18

4.1. The IBM Main rame Charter 18

4.2. Hybrid computing 18

4.3. Workload consolidation 18

4.4. Workload modernization 19

4.5. New Workloads 19

4.6. Main rames and Cloud 19

4.7. Service Oriented Architecture (SOA) 20

5. The main rame business case 22

6. Colophon 246.1 Re erences 24

6.2 Acknowledgements 24

Appendix A.A short history o the main rame 26

Appendix B.

What are MIPS, MSUs and Service Units? 28

2 Mainframes in perspective, the slumbering dinosaur awakes


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and it keeps on going

This White Paper rst appeared in 2007, to con ront the then-prevalent myth that the main rame was dead. We in Atos knewotherwise: we are constantly busy, running critical systemsor prestigious customers on main rames. That work keeps ongoing and growing.

Now it is over ve years later and that market, and themain rame that serves it is increasing all the time.

So, why should we eel at all reticent about extolling the virtueso that main rame? It is not just a case o i it aint broke, dont xit: there are a lot o positive virtues that make the main rame anextremely viable plat orm, now and or the uture.

These days user companies are much more exposed to theoutside world than they used to be: they have customerswanting to access their accounts or order goods via the

internet around the clock, and hackers trying to break theirway into the systems. And all that needs to be backed up by anever-more-complex ecosystem o partners and supply chain. I their systems ail, it can be embarrassingly public.

Now more than ever, there ore, enterprises want technologythat simply works delivering 100% reliability, without uss,around the clock and that runs all the latest systems as well.This is what the main rame, delivered by Atos, can do or you.

Mick Symonds, Atos

Utrecht, March 2013

3Mainframes in perspective, the slumbering dinosaur awakes


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1. Introduction and summary

In their use o IT, businesses have to make acontinuous balance between quality o service(QoS) and cost.

QoS: Improved availability o services

Reduced time to market or new services

Reduced complexity, ease o useCompliance to regulations.

Cost: Reduced purchase and running costs

Increased resource utilization

Reduced administrative overheads

Contract transparency.

Some ashions seem to run in circles andcome back to haunt us. For some o us, itmay seem to be so with main rames: we allused to use them years ago, but then mostorganizations dri ted o onto other plat ormsas they downsized. Now those people are busyre centralizing, and many are reminded o howthings used to be on the main rame.

But it would be a mistake to think that thosepeople will ind the main rame plat orm exactlyas they le t it years ago. The main rame hasnot stood still in that time, but has evolvedalongside other plat orms, while still retainingthe levels o quality and reliability it always had,and the growth in main rame sales is steady.

Main rames, as the big iron o thecomputing world, are relied on by manylarge businesses to:

Per orm thousands o transactionsper second

Support thousands o concurrent users, all

accessing the same systems and resources Allow multiple application programsto access numerous resources, sa elyand securely

Manage enormous volumes o stored data

Trans er vast quantities o data in and outo the system

Interact, as a truly open system, withapplications on other plat orms.

The main rame plat orm has a reputationor its extremely high level o quality but,amongst those who do not use them, orbeing expensive, monolithic and in lexible.Yet it can be very cost e ective comparedto a proli eration o smaller systems, can belexibly con igured and re con igured. It isactually a constantly evolving plat orm.Many times it is not the plat orm that isin lexible, but the procedures built aroundit over time and/or a reluctance to exploitthe new main rame capabilities.

Recent studies, undertaken by IBM themselvesbut endorsed by Illuminata, as well as bycompletely independent parties, show a verypositive cost comparison or the main rameagainst other plat orms.

There are also concerns about it being anisland o computing. In the irst years o itsli e IBM indeed invented its own de actostandards, but arguably had no option to dootherwise, and since then it has been busysupporting industry and de jure standards;these days it is extremely well connectedto other plat orms. And, or the best o bothworlds, the main rame will happily run veryold systems on the old standards alongsidenew ones built to modern standards.

There is urther irony to any resistance tothe use o main rames, because everyonein IT is talking about virtualization and cloudcomputing: but the underlying level o Cloud,In rastructure as a Service (IaaS), is essentiallythe well established utility computing service(see the White Paper, Shaping the Cloud, Atos,November 2011). The concept s involved havebeen around in the main rame world or 40years or more. By providing virtualization,

VMware is doing or Intel plat orms whatVM/370 did on main rames in the 1970s.Main rame is a utility service, and hasalmost always been so. Whilst claiming tobe innovative, many advocates o cloudservices are actually reinventing themain rame in many aspects o what theyare trying to achieve.

With the introduction o zEnterprise, the latestgeneration o main rames, it is also the irstplat orm to deliver an out o the box, integratedhybrid computing solution.

In spite o continual rumors o their death, main rames are alive

and well, and represent a very viable and cost-e ective plat orm orrunning modern IT systems. This may come as a surprise to some,especially those who moved o the plat orm a decade or more ago.

Main rame

LinkedIn Enterprise Systems blog 2013: Whats the best way toexplain what a main rame is to children?n. 1. Its a huge computer that never crashes but you cant playAngry Birds on it. n. 2. A large PC peripheralFrom: The Devils IT Dictionary, Isham Research, www.isham research.co.uk



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A recent analysis by Gartner showed that twoo the most signi icant obstacles to continueduse o the main rame were managementperception (20%), where they cite the Instantexperts, saying I read the main rame is deadin the airline magazine, and opposition romLinux support sta (18%), who dont think themain rame is cool enough.

Nevertheless, the main rame style ocomputing still has a role or those whosebusinesses are dependent on high qualitycomputing environments, and what betterplat orm to supply this need than themain rame itsel ?

This paper explains this apparentconundrum and gives some outlineas to how the main rame plat orm canbest be strategically considered.

At the European air tra c management organizationEurocontrol, located in Maastricht, The Netherlands, its allabout managing air tra c in the sa est possible way. Substantialamounts o data, such as fight data, personnel deployment andtraining scenarios, are continuously processed in real time intouseable in ormation. A reliable and e cient IT environmentis crucial to this task. To achieve such a smart data center,Eurocontrol and IBM are consolidating part o the presentserver environment into a virtual hybrid data center basedon an IBM System zEnterprise Server with Linux as operatingsystem. This is to result in a better view on operations, morefexibility, aster responding applications, greater capacity,higher availability o the in rastructure and considerable costsavings on supervision, licenses, foor space and energy.Eurocontrol consolidates IT environment into virtual data centre,IBM case study, 2011



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2. How we got here:the road less travelled2.1. Market positionIn 1943, Thomas Watson o IBM had amouslysaid, I think there is a world market or maybeive computers. But over the next two decadesa market did indeed arise or a ew moresystems than that. In the 1960s and 70s therewere a number o suppliers o large scalecomputers, known colloquially as IBM andthe seven dwarves: Burroughs, ControlData, General Electric, Honeywell, NCR,RCA and Univac.

The introduction by IBM o the System/360 in1964 was a revolution, mainly because o thenature o the architecture. Be ore then, eachcomputer produced was a unique system,made to a customers order, with no continuityin design. And each was, essentially, a singleapplication system, with di erent systems oreither commercial or scienti ic workloads.

The System/360 was a amily o originally ivemachines, sharing common architecture andperipherals. Customers could upgrade to newerand larger processors without concern as toproblems o compatibility.

The System/360 architecture design brie wasto ul il a number o key requirements:

Handle very large amounts olexibly managed storage, with a varietyo data ormats

High input and output (I/O) rates withstandard inter aces

General purpose processing capability,with controlled supervisor unctions

Scalability, with an initial range o one to i ty.

The S/360 was the irst system to usemicrocode (or irmware), rather than have all oits unctionality hardwired. These stored microinstructions, not accessible to normal programsother than to execute them, provide a level olexibility between the hardware and so tware:i a system needs to be corrected or extended,that upgrade can take place without replacingthe system hardware itsel . The standardarchitectural inter ace was described in adocument called the Principles o Operation.

Such an architecture also meant that othersuppliers (e.g. Amdahl, StorageTek, Hitachi)could build hardware, whether processorsor storage, that would sit alongside that oIBM and be indistinguishable to the systemsso tware, the applications and to end users.This development opened up the main ramemarket to price competition.

Even by the 1970s, with the growth in supplyoptions, computers were still large andexpensive centralised resources, involvingmajor capital investments and with teams osupport specialists, used by large companiessuch as banks or bulk data processing. By thattime, the competition to IBM had become TheBunch: Burroughs, UNIVAC, NCR, Control Dataand Honeywell. This was a US centric view, asthere were other local manu acturers in Europe,such as ICL and Siemens.

The market su ered urther shake out andtake overs in the 1980s. By the early 1990salmost everyone had decided that themarket or the main rame was dying, asmore and more customers down sizedto other plat orms.

Ironically, as a back ofice system, themain rame market was revived in the 1990s.This was partly by the opening up o theplat orm to industry standards, and partly bythe advent o e business and the use o theinternet or commercial activities. The numbero back ofice transactions and the size andactivity level o databases grew enormously,generating a revival in the market.

These systems soon became too big andcritical or a migration to any other plat ormto be considered, or even possible.

2.2. Availability,per ormance and utilisationThe actors o availability, per ormance andutilisation are essentially what determine whatis and is not a main rame. Main rames arebuilt to a level o quality. From the outset, thedesign o a main rame is that it can run multipleworkloads in the same system environmentin the same machine. The emphasis in themain rame world was on improving Reliability,Availability and Serviceability (RAS, as IBMcalled it).

Internal security and integrity was built intothe original S/360 hardware architecture, withprovision or a protected level o supervisormode, containing system instructions or useonly by the operating system.

This continued with the advent in the 1970s,o the irst MVS (Multiple Virtual Storage)operating system, in which system integritywas paramount, and which completely isolatedany one workload rom another running onthe same machine. It made very eficient useo (then scarce and expensive) real memoryresources by sharing them, and doing so verysecurely, by the use o virtual memory, usingdynamic address translation (DAT) to mapvirtual to real memory, and hardware storagekeys to completely segregate the processing odi erent workloads.

The security mechanism within the system,RACF (Resource Access Control Facility), waslater extended to outside resources, suchas storage and network, guaranteeing theworkloads and their data could be securedand completely isolated.

Workloads within a main rame environmentare given the appropriate priority via a policybased workload scheduler and dispatcher.The machine can be loaded up to 100%without per ormance issues; a sustained peakload does not cause major per ormance issues.

Availability was already high but becamehigher in the mid 1990s with the additiono Parallel Sysplex, one o the irst clusteringtechniques, where you can couple up to 32main rame LPARs (Logical Partitions) actingas one machine. The concept is similar toUnix clustering, except systems can be addedor removed as needed, while applicationscontinue to process uninterrupted.Parallel Sysplex allowed concurrent dataaccess rom any node without impactingper ormance or integrity.



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Workloads can be cloned and distributedacross the cluster (load balancing), which canbe spread up to a distance o 20 km cablelength. You can put one hal o your serversin one location and the other hal in anotherlocation, at a distance o up to 20 km in thetwin data centre complex, with them stillacting as one machine. This makes it a per ectclustering technique to deliver a plat orm ortrue continuously available applications.

Disaster Recovery (DR) and High Availability(HA) can be implemented through GDPS(Geographically Dispersed Parallel Sysplex),which in spite o the name is not actuallyParallel Sysplex, but can extend Parallel Sysplexcapabilities over much greater distances (easily100 km and more). It does depend on using theright mix o hardware and so tware.

With the introduction o the zEnterprisesystems in 2010, main rame made its irststeps in the Hybrid Computing arena. For theirst time it is possible to deploy an integratedhardware plat orm that brings main rame anddistributed technologies together: a systemthat can start to replace individual islandso computing and that can work to reducecomplexity, improve security, and bringapplications closer to the data that they need.

Within the zEnterprise System a new conceptin IT in rastructures is being introduced:zEnterprise ensembles. A zEnterpriseensemble is a collection o highly virtualizeddiverse systems that can be managed as asingle logical entity where diverse workloadscan be deployed. Ensembles, together withthe virtualization, lexibility, security, andmanagement capabilities provided by thezEnterprise System are key to solving theproblems posed by todays IT in rastructure.

So tware Virtualization was introduced in1972 with the VM operating system 1. Withthe advent in late 1984 o Amdahls MultipleDomain Facility, the irst real hardware basedvirtualization was introduced.

A ew years later IBM ollowed with a morelexible implementation: PR/SM (ProcessorResource/System Manager). Both aretype 1 Hypervisor implementations thatallow multiple logical partit ions (LPARs) toshare physical resources such as CPUs,memory, I/O channels and access to storagedevices. The hypervisor kernel was builtinto the systems microcode.

Logical partitions (LPARs) can be created torun completely independent workloads underseparate operating systems on the sameprocessor complex. The virtualization is notonly o ractions o server capacity but also omemory and I/O channels. It is interesting tonote that there are no known security breacheso the main rame virtualization environment.

Virtualization has also been extended to otheracilities, such as storage and networks. Earlyon, main rames used virtual storage addressesand multiple channels to the same device toensure lexibility o access. IBM main rameswere one o the irst plat orms to introduceHierarchical Storage Management (HSM),meaning that data stored on disk could bearchived o to lower cost storage, or eventape, and recalled i accessed, all transparentlyto the application or user. Since the early1990s tape robots have been con igurable asVirtual Tape Libraries (VTLs): a VTL presentsa storage component (a Virtual Tape Server VTS usually hard disk storage) acting asa tape library, connected to a real tape robotwith associated library. There are manymore techniques available now (storagereplication, RAID, virtual or thin provisioning,de duplication) to extent this abstraction o thelogical rom the physical data storage.

Two roads diverged in a wood, and II took the one less travelled by,And that has made all the diference.

The Road Not Taken, Robert Frost (18741963)

Virtualization is the creation o a logical abstraction o the physical environment. Itinvolves the de-coupling o an inter ace, so that diferent and variable resources can beused beneath the sur ace. It can make many appear as one, or one appear as many.

Virtualization can be applied to a myriad o resources, examples o which include:

Services: de-coupling what is used rom the in rastructure used to provide it

Applications: using Web Services inter aces, so that multiple customers can make useo a single application process

Servers: running multiple applications on the same box, whether in the same or usingmultiple operating systems

Storage: allowing data to be stored across a range o physical storage devices

Networks: both wide-area (WAN) and local (LAN): running diferent services over thesame cables.

Virtualization can be made to work across an increasingly heterogeneous range odevices, so that devices o diferent types can be combined and replaced. Virtualizationallows increased utilisation o these resources.

1. Comparing Virtualization Methods or Business A Summary, Solitaire Interglobal, 2012



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2.3. Sofware and standardsMain rames retain their continuity largelybecause, although all o the componentsmay change, they maintain strict backwardcompatibility or old so tware. New versionsextend acilities rather than change them, andno one has to undertake a orced migration or

re write because a new version o the hardwareor so tware emerges.

Multiple operating systems can be run onthe main rame:

z/OS: the lagship operating system orhigh availability and high load workloads,evolved rom MVT, MVS, OS390. In z/OSyou can even directly run Unix programs,because it contains a POSIX standard Unixunder its hood

z/VM: a hypervisor, allowing multipleoperating systems to be run within onecomplex, evolved rom VM/370; z/VM isnowadays mostly used as hypervisor orLinux on z systems, running hundredso virtual Linux systems in one z/VMsystem environment

z/VSE: a smaller operating system,originally or lower end systems, evolvedrom DOS, DOS/VSE

Linux on z: a ull Linux implementation,available as either SUSE (Novell) orRedhat distributions

z/TPF: a real time, large scale and veryhigh volume online transaction processingenvironment, developed as a special OS orairline reservation systems and paymentcard processing.

They can all be run in an LPAR, under control oa hardware hypervisor, or under z/VM.

IBM introduced the concept o ArchitecturalLevel Sets (ALS) to couple the levels ohardware and operating system support:an ALS de ines the architectural eaturesand unctions that are required to physicallybe present on an IBM main rame systemto support a certain level o the OS. Theseencapsulate the airly long li ecycle supportcycles in this environment 2: typically, a newmodel range emerges every 2.5 years or so,but can be used or between eight to ten years.

Middleware irst arose in the main rame worldas a layer o so tware above the operatingsystem to acilitate building and runningapplications. Within the operating system youhave the choice o a number o middlewareenvironments:

Database management systems (DB2, IMS,IDMS, Datacom, Adabas)

Transaction processing systems (CICS, IMS,IDMS, TSO, Roscoe)

Batch

Third generation languages (good oldCOBOL, Fortran, PL/1, Pascal, C,Assembler, JAVA)

Fourth generation languages (4GLs: Focus,Natural, Mark IV, EGL)

Web hosting (Websphere, Apache, Weblogic)

Independent So tware Vendor (ISV)o the shel applications (SAP, etc.).

The vast majority o main rame programsare still those written in Cobol, with asigni icant use o PL/1, Assembler, C and C++.Growing proportions are now being writtenin Java, especially with the growth in SOAand Web Services.

There is a large and mature set o systemmanagement tooling to automate operations,schedules, security management, tape anddata management.

2.4. Cost o ownership or usageBecause o its innate scale, the main ramehas never been cheap to own, but to helpcompensate or that it can be very highlyutilized and the various workloads can be runalongside each other with complete integrityand security. So it is very appropriate to sharea main rame between multiple customers,making the cost o usage more acceptable.Several independent studies show that when

applying real TCO (Total Cost o Ownership)comparisons in many cases the main rameeasily wins over distributed systems.

2.5. The evolution o computingComputing has evolved in a number o waves,each seen as a new paradigm and a radicalimprovement on what went be ore:

2. The Top 10 Factors Involved in Determining the Li e Cycle o Your IBM Main rame, Gartner G00211475, March 2011



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Central computingServer-centricMainframes and dumb terminals

Central control and managementIn lexible use

Distributed computingClient / ServerFat clients: unlocked, then lockedEase of use, customizableHeterogenous, di icult to manage

Server-based computingServer-centricCentral control and managementThin or fat clientsApplication-oriented, lexible use

Enterprise portalsServer-centricCentral control and managementFlexible use, customizableUser-oriented

Utility computingServer-centricComputing on DemandIT as utilityMerged into cloud

Cloud computingInfrastructure as a ServiceServer, storage and networkFrom boxes to server modelStill evolving...

More standardized, but ownership constraints removed

More choice,lower IT and business cost

Improve usability,lower build cost

Increase manageability,lower IT cost

Enhancedexibility

The evolution o computing

Rather than remaining stuck behind in theoriginal model, main rame processing hasactually ridden many o these waves. Indeed,within an up to date main rame environment,it is possible to implement the best aspects oeach o these models o computing.

The main rame architecture, while retainingcompatibility throughout, has itsel evolvedover the decades:

1960sSystem/360 in 1964: the original introduction.

1970sSystem/370 in 1970: adding multi processing,more instructions and virtual memory.

1980sS/370-XA (eXtended Architecture) in 1983:bringing 31 bit addressing.

1990sESA/390 (Enterprise Systems Architecture)in 1990: supporting the use o multipleaddress spaces.

2000sz/Architecture in 2000: bringing 64 bitaddressing and dynamic channels.

2010szEnterprise in 2010: a step into the hybridcomputing environment that includesmain rame and distributed systems;workload that spans System z and AIX,Linux and/or Windows.



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3. How does legacymain rame t withincurrent IT?

In act, the greatest long term threat to themain rame market comes not rom anyweakness in the plat orm itsel , but rom thecontinued evolution o other plat orms to alevel that is good enough to replace it.

3.1. Market positionThere used to be many plat orms other thanthe IBM System z which were described asmain rames: Unisys manu actured ClearPathsystems and their ES7000 was sometimesdescribed as an Intel main rame. HP sold theex Tandem NonStop systems, and GroupeBull the DPS system, and there was theDEC/VAX 9000 series. Whilst these did havesome characteristics in common suchas designed in high availability throughredundancy the IBM System z has wellover 90% o market share in this ield: it isthe main rame.

It will be seen rom the accompanying graphrom ITCandor that there is a continuingsubstantial market or main rame systems,which has recently been experiencingsigni icant growth. This seems to arise becausethose or whom the main rame was notsuitable have already moved o the plat orm,and those who remain are still growing theirusage along with their business.

From the most recent IBM Annual Report,Revenues rom the Systems and Technologysegment totaled $5.8 billion or the quarter.Revenues rom System z main rame serverproducts increased 56% compared with theyear ago period.

IBMs revenues rom main rame hardwarealone are believe to be around $4.3 Bnper year 3, to which so tware and servicescan be added.

Those revenues have remained approximatelylevel in recent years while the number oprocessor MIPS shipped has increasedmani old, indicating that the price per MIPShas dropped signi icantly over that period.Indeed, that trend is shown clearly in theollowing graph, which also shows how ithas reduced even more dramatically orspecial purpose MIPS.

Why is the main rame still being built and used? They continue toprovide the ability to run database, application, le server, web server,rewall, etc., all on one machine, and do so at a very high level o security and reliability.

2004 2005 2006 2007 2008 2009 2010

zEnterprise

Growth

Size

z10 2097z9 2096z9 2094

z890

z10 2098

$0

$1

$2

-15%

-10%

-5%

$3

$4

$5

$6

$7

0%

5%

10%

15%

20%

3. Start Planning or the Next Generation o IBM Main rames, Gartner, G00226761, January 2012

IBM system z revenue ($US Billion) and revenue growth withmajor product introductions 2004-2010 rolliing 4Q Analysis

Source: ITCandor, January 2011



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In summary, there are lots o numbers whichare still going in the right direction or themain rame, even a ter all these decades.

20010%

120%

2002 2003 2004 2005 2006 2007 2008 2009

100%

80%

60%

40%

20%

Special purposeGeneral purpose

YE03 2Q12YE04

BladeCenter Extensionunits; 1100+ bladesshipped

150+new accounts since3Q10 zEnterprise launch,with 1/3 in growthmarkets

140+of the top 100 banks inthe world run IBMSystem z

96of Top 100 clients haveinstalled IFLs

2/3+ISV apps run on IBMSystem z; 45 new ISVsadded in 1H2012

7,400+schools in 67 countriesare part of the IBMAcademic Initiative forSystem z

1,067

(source: IBM2012)

YE11YE10YE09YE08YE07YE06YE05

System z total instaled capacity

The growing IBM zEnterprise System ecosystem

IBM cost per MIPS



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3.2. Availability, per ormanceand utilizationMain rames provide very high levels oavailability and ault tolerance, and aredesigned not to have single points o ailure.More than any other sizeable plat orm, thesesystems have redundant internal componentsand engineering: IBM System z servers executeevery instruction twice, in parallel, and comparethe results (lock stepping). Workloads can beshi ted in light to spare processors, withoutimpacting the running systems.

In days when many suppliers talk in terms o ive 9s availability4, it is salutary to recognisethat most main rames already currently deliver100% availability (although committed servicehours may be less than that igure). They doso with high levels o per ormance (there istypically no lower Quality o Service (QoS)option with main rame services) and with aMean Time Between Failure (MTBF) o over20 years. Indeed, there seems to be somedebate in the industry as to the MTBF or themain rame plat orm: it is variously described asover 20 to over 30, or even 50 years.

An Eagle Rock Alliance survey rom as longago as 2001 identi ied monetary downtimecosts or a range o users: i was greater than$50k/hour or more than hal and over$1m/hour or 8%. Systems have probablybecome even more critical since then, withcontinuing adoption o real time accessand commerce via the Internet. That surveyemphasises why it may be worth paying moreor a high level o availability.

The main rame plat orm is also inherentlysecure because there is no threat o viruses andlimited threat o hacking; viruses on main ramesare made impossible by its architecturalstructure. It is not so publicly understood oravailable a plat orm as is Windows, so teenagehackers cannot hone their skills in the com orto their bedrooms. Not only would such athreat be harder to produce, but it would beharder to implement: service providers donttend to set up main rames unprotected inopen environments like the cloud, as they dowith some other servers. And even i it couldbe hacked, it would have very limited impactbecause o the architectural design andthe internally secure nature o the plat orm:everything runs in its own address space, keptapart rom each other by mechanisms withinthe hardware and microcode.

The main rame can also deliver high levels oservice due to its server architecture, consistingo separate Central Processors (CPs) andSystem Assist Processors (SAPs) like dedicatedInput/Output Processors (IOPs), processors orcryptographic services (CryptoExpress) andwith spare processors ready to take over inlight i any o them ails. The processors aredeployed using dispatching algorithms whichensure that, unlike some other plat orms,processors do not have to wait or I/O orother ofloaded processing like encryption/decryption to complete.

The main rame is also remarkable or itsscale, in terms o the sheer volumes o dataprocessed (processing capacity o up to 78.400MIPS in one physical box), data stored andtrans erred (up to 288 GB per second), up to3TB o real memory and, since the introductiono zEnterprise, also leading in clock speed (5.5GHz processor in a zEC12).

In Triggers or re reshing servers, June 2005,and thus pre mass virtualization, Forresterstated that The current average capacityutilisation or Wintel based server environmentsis typically 8% to 15%, and 28% to 45% orUnix/RISC based systems. For main rames likeIBM System z is 65% to 75%. Main rames can,and do, happily run at 100% utilization orlong periods.

So the main rame is still unchallenged, in that itcan be ully loaded with an enormous volumeo work which it will continue to processinde initely and uninterruptedly, with no ussor bother.

3.3. Sofware and standardsIn the irst 20 or so years o the main ramesli e, IBM invented its own de acto standards;indeed, it is arguable that it had to do so. Butsince then, with the advent o distributedcomputing and the internet, IBM has been busy

supporting industry and de jure standards.

In line with other aspects o the main rame,though, you can continue to use the oldstandards alongside the new: the main ramesupports TCP/IP networking (as well as SNA andVTAM), LDAP directory services (as well as itsown directory and security catalogues), OpenSource, DB2 connectors, ile sharing, etc.

A main rame environment is inherentlyversatile: it can run a range o IT environments:

Old so tware: programs written decades agoin Cobol, PL/1, Fortran or even Assembler stillwork on the most modern system Multiple application environments canco exist: batch, online, interactive andweb access

The most modern plat orms are alsosupported: Java, Service OrientedArchitecture (SOA, using Websphere),C++, XML, etc.

4. Readers should always be wary o easy claims o high levels o availability. Costs increased exponentially or every 9 added,and 99.999% availability actually equates to only 5.26 minutes downtime per year, or 6 seconds per week: see https://en.wikipedia.org/wiki/High_availability.



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A main rame can run those 25 year old Coboland CICS applications, alongside those whichhave been recently written using SOA and Java.This, although the hardware, operating systemand middleware have all undergone majorchanges in that time; backwards compatibilityhas been ensured to protect investments inhistoric so tware. That, indeed, is why there isso much legacy so tware to worry applicationmanagers: it wasnt broken, so it didnt needixing, sometimes or decades.

There are over 1,300 independent so twarevendors (ISVs) supporting the main rameplat orm, a number which is actually increasingaccording to Gartner.

3.4. Speciality enginesMost multi processing environments consist oprocessors which all access the same resourcesand per orm equivalent unctions: SymmetricalMulti Processing or SMP. Sometimes, though,

a processor can be con igured to take onparticular tasks, such as the maths or graphicsprocessors in a PC.

IBM has announced a number ospecial purpose processing engines whichcan be installed into a main rame. They are,in order o appearance:

IFL Integrated Facility or Linux

Introduced in 2000

From 127 MIPS per processor in 2000 toapproximately 1550 MIPS in 2012.

zAAP System z Application Assist Processor,or Java and XML

Introduced in 2004

Starting with z10, merged with zIIP.

zIIP System z Integrated In ormation Processor

Introduced in 2006

Initially or DB2 only, later also or otherdatabase related workloads.

The advantages o these speciality enginescome partly rom the act that theyofload some o the processing rom thegeneral purpose engines within the system.

The main reason however, is that they comewith an increasing price advantage, both orthe hardware (see graph) and also as regardscharging or the so tware which runs within thesystem: this is normally charged on processorcapacity basis, yet the capacities o thesespecial engines are not counted or the normallicense charges.

20010%

120%

2002 2003 2004 2005 2006 2007 2008 2009

100%

80%

60%

40%

20%

Special purposeGeneral purpose

IBM cost per MIPS



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3.5. Cost o ownership or usageIn spite o their reputation or being expensive,there are main rame advocates (e.g. the Arcatiresearch group) who claim that main ramesare very cost e ective, when comparedagainst Unix, Linux and Windows running ondistributed systems, on a per user basis.

They claim costs as follows:Main rame $4,500Unix $5,400Windows $8,000

But it is dificult to make an apples with applescomparison in this context, and di eringanalyses do produce di erent results.This avorable analysis is seen as beingespecially true where there are a largenumber o end users wanting to use the sameunctionality, because the other plat orms donot scale so well, and over a ive year period,because we are considering stable workloads.

Also running main rame services at an externalservice provider (ESP / outsourcing) will bene itthe business case in avour o main rameby exploiting the economies o scale andscalability capabilities in a shared environment.The ollowing table, rom Gartner, illustrates thatby showing the average cost per installed MIPSor a range o scales:

The cost per Installed MIPS has reducedconsiderably over recent years, rom measureddata, as tracked by Gartner.

IBM themselves have undertaken studies,endorsed by Illuminata, showing main rameshaving 5-60% cost advantages over Unix, Linuxand Windows alternatives. This is predicatednot on a one or one comparison, but on thecost o running 10-50 applications on onemain rame, versus 10-20 blades or a grid o50 systems.

Some speci ic aspects o this study are worthyo urther highlighting and consideration:

The main rame requires less electricity andaircon than many 1U racked servers runningthe same load. This is very signi icant in amodern data centre environment, wherethese components are much more o aconstraint than space

The balance o cost components havechanged radically in the last decade:

people costs increased rom 14 to 29%

hardware costs decreased rom 65 to 14%.

The current distribution o main rame costcomponents is shown in the ollowing diagram,rom Gartner group.

There are claims o benchmarks showingthat an SAP environment with more than1,500-2,000 users is least expensive to runon a main rame. Whilst IBM is strengtheningtheir alliance with SAP, initially in the DB2 areaas a competitive product to Oracle, SAP isreciprocally pushing the IBM DB2 plat orm,including SAP on main rame as the high endresilient solution.

The one weakness in the cost analysis ormain rame environments is the so twarecomponent. Indeed, according to Gartner thiscan amount to 44% o the cost o ownership.This is partly because some ISVs treat theplat orm as a cash cow. Developments suchas the provision o a Linux environmentmay help to address this aspect. Anotherpossible remedy is the advent o organizationswhich specialize in migrating environmentsrom known dificult ISVs packages to lesstroublesome so tware.

The cost o any conversion also needs to bebrought into the balance: Gartner Group hasstated that, While the overall number o IBMmain rame customers is declining (as thenumber o smaller customers migrating o themain rame each year exceeds the number oirst time customers), most large enterpriseshave accepted that their legacy applicationsuites (typically written in Assembler orCOBOL) will need to remain on the main rameenvironment. Even i the same per ormancecould be achieved on di erent plat orms at alower cost, the porting or rewriting needed toachieve this is o ten prohibitively expensive.

Also, there are assertions that any main rameenvironment o more than 1,500 MIPS(although the igure varies) is too dificult andcomplex to move to another plat orm 5.

Environment sizeinstalled MIPS

Small6,000 Installed MIPS

Average 61.2% 65.1% 72.5%

Source: Gartner IT key metrics data (December 2012)

5. Proo Points For Main rame Application Migration, Forrester Research, September 2011

2009 2010 2011 2012$0

$2,000

$4,000

$6,000

USD

$4,496$5,048

$5,575

$3,566

Annual main rame cost per installed MIPS, 2009 2012

Main rame Utilization Rate: by Environment Scale




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3.6. EnvironmentalconsiderationsIn terms o power and cooling, main rameswere previously (pre 1995) a concernbecause o their need or water cooling.But a highly utilized main rame is much moreeficient than a room ull o under utilizedWindows servers (as per Forresters estimates).

Their low environmental impact is now seenas one o the strengths o the main rameplat orm. With the introduction o thezEnterprise zEC12 system, IBM has reintroduced the option or water cooling orenterprise, ocusing on Green IT.

3.7. Main rames andCloud ComputingCloud computing is lavor o the momentin IT, but is this all quite as new as we areled to believe? Or is the main rame a classicimplementation o a cloud computingenvironment? 25 years ago, manycompanies were doing utility basedcomputing on main rames:

They ran a standard (albeit proprietary IBM)architecture: S/370

Multiple business units were processing inthe same environment

The systems were o ten owned by suppliers,whether internal or external

They undertook capacity planning,per ormance and availability management

They used sophisticated tooling to automate,charge, secure, archive.

Then along came Distributed Computing,consisting o :

Di ering proprietary in rastructurearchitectures: every box was di erent

Dedicated box(es) per application, leadingto server sprawl

Dedicated storage per processor box,causing a nightmare or capacity plannersand storage administrators, etc.

Later developments in distributed computingled again to re centralizing and UtilityComputing initiatives.

New technologies now provide the neededaspects to allow these other environmentsto deliver using some o the same servicecon igurations as the main rame always hasdone: e.g. SANs that work across multipleplat orms, architectural compatibility betweensystems, sophisticated tooling to manage theworkload and provision systems to run it.

These acilities are now being extended by thewidespread use o virtualization: separatingthe logical application environment romthe physical system(s) on which it runs, andallowing multiple applications to run on thesame box. Virtualization is now well establishedin the Unix world and is making great headwayor Windows systems. This is an approach,indeed a technology, which has been present inthe main rame world since the 1970s.

So, in many ways, current moves towards cloudcomputing are reinventing the main rame.

Especially a ter the latest announcemento zEnterprise with hybrid capabilities,main rame is very well positioned to play alarge role in cloud computing, speci ically tothose shops that have already main rameexpertise in house.

2%3%3%29%44%14% 5%

0% 10% 20% 30% 100%90%80%70%60%40% 50%

Hardware

Facilities / Occupancy

Software

Disaster recovery

Personnel Connectivity

Unallocated


Distribution o main rame costs



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3.8. Greying o the work orceFrom a completely di erent perspective,there are ears o a shortage o availablemain rame skills, as the IT support populationages and retires, but many o these andother developments may also help addressthat concern:

Main rames are much easier to supportthese days: previously an army ohighly trained specialists was required 6 ,but the tools to manage a main rame

plat orm have improved enormously,so routine unctions can be done bylesser skilled resources with much lessrisk and exposure:

z/OS has a build in Health checker. Itprovides a oundation to help simpli y andautomate the identi ication o potentialcon iguration problems be ore they impactsystem availability

System dumps no longer need to beanalyzed in house: rather the system willindicate to which o your so tware suppliersit should be sent or resolution

The development o a Main rameCommunity as part o the Main rame Charter(see later) includes making main ramesavailable to colleges across the world, sothat students can gain hands on experienceas part o their learning o IT skills. IBM nowhas more than 150 universities around theworld (50% in the Americas, 30% in Europeand 20% in Asia) enrolled in its AcademicInitiative program

Linux already has an enormous amounto adherents, is very well adopted withinacademic circles and has its own communitysupport. Combining this Open Sourceapproach onto the main rame plat orm couldalso yield enormous bene its and make skillsmuch more available

The advent o architectures such as SOAmeans that those using the plat orm as acomponent o their applications environmentneed much less knowledge o the underlyingplat orm. Indeed, they may not even know onwhat plat orm a speci ic unction is provided

IT service supply models such asoutsourcing and o shoring mean that userscan contract any remaining problem tosomeone else, who can bene it both rommuch greater economies o scale, and romthe use o a well trained and disciplinedwork orce in other geographies.

6. The key measure or stafing in this environment is Installed MIPS per main rame FTE, which is enormously improved but still varies depending on the scale o installation (source: Gartner).



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4. New developments withinthe main rame world4.1. The IBM Main rame CharterIBM does seem to recognise that themain rame plat orm has a perhaps un airreputation as being a bit o a dinosaur.This may be un air i the technology is judgeddispassionately, but partly arises because osome genuine concerns, such as whethercustomers will still be able to retain theservices o suitable technicians once the irst generation o support sta has all retired?

There are good commercial reasons why

IBM should try to maintain and enhance thisplat orm as long as it can: it is very pro itableand there is very little direct competition.

IBM responded to this situation in 2003 withthe creation o the Main rame Charter: this wasand is a set o nine statements (see box)in which it promised to continue innovation,o er value and oster a support community.

This seems a worthy intent, albeit one whichis in its own interest. Main rames do seem toengender loyalty, and there genuinely is, andhas or a long time been, a sense o communitywithin the main rame world, somewhat

redolent o that within the Open Sourcecommunity. Indeed, with the use o Linuxon z, those two communities do seem to itwell together.

4.2. Hybrid computingWith the 2010 introduction o the nextgeneration main rame (code named theGryphon hal lion / hal eagle), IBM Systemz made its irst steps into the world oHybrid computing.

In act the introduction was three old:

A new generation o main rames zEnterprise with the typical characteristicso a new machine: better, bigger, aster, moreo everything

zBX: the System z Blade center eXtension,capable o running IBM Power7 (AIX andLinux) and x86 blades (speci ic appliancesand accelerators) in tightly coupled racks. In2011 this was extended with Windows

Uni ied Resource Manager: allows the

supported zBX plat orms to be virtualizedinto a single system or management. Italso allows or the prioritization o certainworkloads in the system. URM can monitorthe various plat orms or signs o bottlenecksor aults, and modi y the overall system torecover, maintaining a speci ied quality oservice level at a workload level.

Together with the introduction in 2012 oanother new zEnterprise system (zEC12), theIBM DB2 Analytics Accelerator (IDAA) was alsobrought to light. It runs complex queries upto 2000x aster, while retaining single recordlookup speed, and eliminates costly querytuning while ofloading query processing. It iscomparable to Oracle Exadata or SAP HANAtechnologies, but then completely within azEnterprise complex.

4.3. Workload consolidationLinux seems to be a very attractive optionor the main rame environment, both orsystems to be converted rom a previousz/OS (MVS) environment and also as a targetor consolidation. Many Linux systems withvariable load can be consolidated into onemain rame environment, with the addedadvantage o in machine trans er speeds

between them.

Linux runs 33% o the net new MIPS beingshipped, according to Gartner Group, and 60%o main rame users are using some Linux onthe plat orm. Almost 225 ISVs currently deliverover 600 applications running on Linux on theIBM main rame, according to Bloor Research.

Linux skills are readily available and can easilybe ported to this plat orm.

The IBM Main rame CharterIt is our intention to continue to:

Provide Innovation:

Provide leadership in innovation toenhance the use o IBM eserver zSeriesto support increasingly integrated andlexible business processes or the ondemand business

Maintain zSeries position as a benchmark

or lexible, eficient, and responsiveplat orms or highly complex, integratedenvironments running a wide range omission critical workloads

Improve the automatic and sel managingcapabilities o the zSeries while workingto simpli y user processes and systemadministration tasks.

O er value:

Enhance the value proposition andlower the cost o computing o zSeriessolutions in a way that is compelling,clear, and consistent

Extend the on demand characteristicso zSeries servers highlighting itsstrengths as an environment orusage based computing

Increase the ability to account orallocation and use o zSeries resourcesin an on demand environment.

Foster a community:

Support programs designed to ostervitality in zSeries community, helping topromote a strong application port olioand world class service

Provide the skills and expertise to assistcustomers in designing, developing, anddeploying on demand solutions built on aoundation whose cornerstone is zSeries

Leverage key open standards andcommon structures to enhancethe use o zSeries in large,heterogenous environments.



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4.4. Workload modernizationThere are a number o known and proventechniques that can be used when aced withold applications running on the main rame,which can range rom reshening them upin situ to complete conversions to anotherplat orm, with di erent levels o changes intheir end user appearance.

Many o these can take place as so tmigrations, where the existing and newenvironments co exist seamlessly, and the

users trans er in groups or the applicationstrans er module by module.

The general approaches include:

Upgrade: the deployment o new so twaretechnologies on the existing plat orm

Migrate: transition o existing applications toa new optimal plat orm

Regenerate: generation o new code basedon the existing application model and/orapplication source code (e.g. Cobol to Java)

Replace: development o complete newcode, and/or purchase o commercial o

the shel (COTS) so tware.

It will be recognized that these are notexclusive approaches, given the modularity andcomplexity o most applications environments,and that a blend o approaches may beappropriate, depending on the circumstances.

Some examples o how modernization can beapplied are:

4.4.1. GUIfying: putting a new GraphicalUser Interface (GUI) in frontTo replace 3270 (dumb) terminals with amodern web based ront end.

4.4.2. SOA (Service OrientedArchitecture) front endLeaving most o the existing applicationscode in place, i it is suitable, and opening upthe environment by putting an SOA inter acein ront o it. The application can then take itsplace in a more complex multi applicationenvironment, connected in various ways (e.g.via an Enterprise Service Bus (ESB)).

4.4.3. Migrate to JavaTypically, where applications are running on aDBMS (e.g. IMS or CICS), written in COBOL.

IBMs Rational EGL (Enterprise GenerationLanguage 7) may be used as a means oconversion: it is similar in many ways tolanguages such as COBOL and Java, but withenhanced modelling capabilities. The resulting

so tware can use special purpose engines (e.g.zAAP), yielding considerable cost savings.

The code is converted (typically, 98%automatically) rom languages such as COBOLto EGL, which can in turn generate Java code.Some speci ic subroutines (e.g. in Assembler)may need to be converted manually.

The database may be able to continue in useas is, or be replaced. I it is replaced, there maybe a need or some data conversion, e.g. romEBCDIC to ASCII.

There are multiple companies delivering

similar solutions, some as a one time service,others as a so tware product, e.g. MicroFocus,Bluephoenix, PKS.

4.4.4. Re-hostingMigrating main rame workloads to what areperceived as being lower cost plat orms 8.Typically, these are to other dedicatedplat orms, one o the options or which is Linuxon z; some organizations envisage doing soto Cloud environments, but these are typicallyPrivate rather than Public Clouds. Variouspackage solutions exist to enable this approach,either by re hosting or code trans ormation.

4.5 New Workloads

To counter the application migrations o themain rame and to attract new workloads, inlate 2009 IBM introduced the Solution Edition(SE) program or the zEnterprise. This delivers azEnterprise main rame as a bundle o hardware,so tware, middleware, and maintenance at asteep discount, but is workload speci ic. Theprogram addresses some speci ic applicationsand workloads, including ApplicationDevelopment, Cloud Computing, EnterpriseLinux, and SAP.

The SE or SAP program claims to make itmore a ordable or companies to bene itrom the strengths o System z or their SAPenvironment: i they are already running SAPin a distributed environment, they can bring itto the main rame through SE or SAP.It can combine with DB2 on z/OS at a specialprice and (optionally) Linux on System z bytaking advantage o the System z SE orEnterprise Linux.

Hybrid computing environments also can beaccommodated under the SE program.For example, when implementing the SAPdatabase server with z/OS and DB2 onzEnterprise, companies may choose toimplement the SAP application server onzEnterprise with Linux on z, or on the zBXwith POWER7 blades and AIX. This comesat a higher cost saving as both the zBX andUni ied Resource Manager are consideredSE optional products.

7. See https://en.wikipedia.org/wiki/EGL_(programming_language)8. Rehosting Main rame Workloads in the Cloud, Gartner G00218073, November 20129. See The main rame and the cloud, The Bathwick Group, November 2010



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4.6. Main rames and CloudFor Cloud environments, there are pushes toposition the main rame as a suitable vehicle orthe provision o Private Clouds: those hostedwithin and or the sole use o an enterprise 9.It is based on a scale up, rather than theusual scale out model, but has inherentadvantages o elasticity and multi tenantsecurity, with an increasing ability to integratewith other plat orms. But main rames havealso ound their way into Public Clouds,such as Amazon.com

A speci ic con iguration, the zEC12, has beencreated, which can run thousands o distributedLinux systems, and can be coupled with thezBX to support Windows and AIX alongside.

4.7. Service OrientedArchitecture (SOA)

Many businesses continue to rely on theirmain rame based application systems toprovide critical transactional business support.But they need to ind a way to open up thatplat orm, stop it being such an island, and allowit to take its par t in the wider set o applicationsand IT systems within the enterprise.

Service Oriented Architecture (SOA) is anapplication development and processing modelwhich is very modular, and allows applicationunctionality to be broken into components andexposed to other applications.

SOA: Standards based components reused andcombined as required

Sel describing: standard ormat o requestand response

Sel contained: not tightly coupled

Location independent: in terms o networkor geography.

Web Services re ers to the way in whichthese SOA service components can be madeaccessible via a web (intranet or internet)inter ace, making them accessible romother parts o the organization or evenother organizations.

SOA depends upon having building blocks ounctionality: a system or systems which hostparticular in ormation or per orm particulartasks when invoked in a speci ic way.This succinctly describes many legacymain rame environments, which is why theyare particularly amenable to being wrappedin an SOA environment.

Technologies to SOA enable legacy (e.g. CICS)

applications use Websphere as a ront end.Websphere is the predominant, Java based,plat orm or these developments in anIBM environment.

I legacy systems needed to provide businessprocess support that can be ront ended byan SOA environment, they can then beknitted together with other systems, makingup a complete environment rom thesemodular components.



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5. The main rame business case

That said, the main rame has uniquecharacteristics. In most cases, it e ectively

delivers 100% availability: there is no lowQuality o Service option or main rameservices, which have a MTBF o over 20 years.

To run main rames eficiently, however, youdo need a certain critical mass. It is debatablewhat that level is, but the breakpoint seems tobe in the scale o 7,000 MIPS. At that point youcan make eficient use o the Parallel Sysplexenvironment and the scaling licence ees.So, many users are now opting to have theirmain rames run by a service provider, whohas the critical mass o both systems andskills in order to maintain and developthe environment.

Conclusions: I you already have a main rameenvironment, you may very well ind thatthe best approach is to keep it, and evenconsolidate other systems onto it

Possibly you could look to get it managedor you, even i you retain other plat ormsyoursel : you dont have to own a main rameto be able to use one

Simpli ication is key to the managemento these environments: create a single,coherent environment

These systems could be the target or

large scale consolidation: you can runhundreds o Unix or Linux images onone main rame.

Users o main rame environment can also bestposition or the uture by reducing the barriersbetween main rame and non main rameplat orms. This includes using technologiessuch as Linux and SOA, described elsewhere,and standard operating processes, such as ITIL.The less a main rame sits in a stand alone silo,the more it can be integrated to take its part inuture IT services, and the less risk there is ohaving dificulties supporting it in the uture.

As has now been explained at some length,the slumbering dinosaur is awake, and is readyand able to maintain its right ul place in theport olio o modern IT solutions.

Rather than being treated as being legacy, the main rame plat ormcan just be seen as another plat orm within a range o currentoptions, with its own per ormance and cost characteristics. And asone which ul ls that role while it is still running the vast number o business-critical applications it brings as its heritage.

Perform a full assessment of currentmainframe applications and infrastructure,

including criticality and prognosis

Compare TCO with projected TCOor alternative platform

Seek a reliable andpredictable migrationprocess or o ering

Seek to optimizeand consolidate themainframe environment

Use mainframeas consolidation target

for other systems?

Add other appropriatesystems to the mix

under consideration

(Out)-sourcingpolicy?

OutsourceDo it yourself

Are systemsmodern andup-to-date?

Determine strategy for further life-cycle maintenenceof both the application and the platform

Move onto lessexpensive h/w + s/w

combination

Solve ityourself?

Can appilcationsbe replaced by standardapplications or moved to

another platform?

Are there realisticlevels of savingsto be made?



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6.1. Re erences Architecture o the IBM System/360,Amdahl et al, IBM Journal o R&D, 1964 IT Key Metrics Data 2013: Key In rastructureMeasures: Main rame Analysis: Multiyear,Gartner Benchmark Analytics, G00246747,December 2012

Progress Report or IBMs zBX, Gartner,G00231027, March 2012

Rehosting Main rame Workloads in theCloud, Gartner, G00218073, November 2012

Proo Points For Main rame ApplicationMigration, Forrester Research,September 2011

Server Sprawl And Cost Reduction Bring

New Customers To Main rame/LinuxPlat orm, Forrester Research, July 2011

Comparing Virtualization Methods orBusiness, Solitaire Interglobal, 2012

Triggers or re reshing servers,Forrester Research, June 2005

The Arcati Main rame Yearbook 2013,Arcati Research, 2013

Shaping the Cloud, Atos, November 2011

Blog: Dancing Dinosaur(www.dancingdinosaur.wordpress.com).

6.2. AcknowledgementsThe editorial team or this white paper wasled by Mick Symonds, with contributions romHerbert Voskuil, Paul Bles and other Atos sta .

For more in ormation, please contactyour local Atos representative, emailto main [email protected] orvisit www.atos.net/main rame

6. Colophon



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A short history o the main rame

7 April 1964IBM announces the System/360: a amily o ive increasingly power ul computers that run the same operating system and canuse the same 44 peripheral devices.

1968CICS (Customer In ormation Control System) is introduced. It allows workplace personnel to enter, update and retrieve dataonline.

1968S/360 model 85 introduces high speed cache memory, making high priority data available 12 times aster than ever be ore and laying the oundation or the same cache memory ound across much o todays computing technology.

1970The Plug Compatible Manu acturer (PCM) market arises: by 1970, over 80 companies have over 200 products compatible withthe S/360 architecture and its peripheral devices.

1970The S/370 as successor o the S/360 is introduced. The S/370 Model 145 is the irst computer with a ully integrated monolithicmemory (all resistors, capacitors and diodes on a single slice o silicon). Be ore this semiconductor technology, magnetic coretechnology was used.

1971Amdahl comes with a clone o the S/370. Gene Amdahl was chie engineer or the IBM S/360 program, he starts the Amdahlcooperation. The Amdahl machines are air cooled whereas the IBM machines are water cooled.

1972 IBM announces VM virtualization, with the VM/370 operating system.

1972SAP develops a revolutionary ERP system or S/370. For the irst time, companies can place orders and track inventory in realtime.

1976 SAS so tware creates a new competitive edge: business intelligence. With SAS you can get intelligence out o raw data.

1981The successor o the S/370 is the 3081, which uses less energy and space than its predecessors. With it comes eXtendedArchitecture (XA), providing dynamic channels and 31 bit (2 GB) addressing.

1983 MVS/XA shipped: an operating system to exploit the new architecture.

1984 Amdahl introduces MDF (Multiple Domain Feature) the irst hardware partitioning tool on the Amdahl 470 main rames.

1988IBM introduces PR/SM , the answer rom IBM to Amdahls MDF. Now hardware partitioning with Logical Partit ions (LPARs) arepossible on IBM main rames.

1988 DB2, IBMs relational database management system is introduced.

1988 MVS/ESA and VM/XA operating systems were introduced, relieving the memory constraints which limited the size oapplications by using new architectural constructs.

1994 The Parallel Sysplex is announced, which makes it possible to share 32 main rames in a single cluster.

1994Unix on the main rame was announced. OpenEdition, later renamed to Unix System Services is an integral part o theoperating system OS/390 (In 2000 the OS is z/OS)

1995CMOS based processors are introduced into the main rame environment, setting the new roadmap or modern main rametechnology. CMOS machines required 1/20th o the energy and 1/10th o the loorspace compared to the older machines.

1999Capacity Upgrade on Demand (a utility like commercial construct) provides extra capacity which can be turned on as dictatedby business needs.

1999Linux appears on the main rame, combining the lexibility o open source computing with the legendary scalability andreliability o the main rame.

Appendix A. A shorthistory o the main rame



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2000IBM introduces the eServer amily o servers were the various sub brands were rebranded all at the same time. IBM S/390became IBM eServer zSeries ( z or Zero downtime). At the same time introduced the 64 bit version o the operatingsystem z/OS.

2003The Main rame Charter is introduced by IBM. It articulates IBMs commitment to deliver innovative solutions, expand zSeriesvalue and oster a zSeries community in order to meet customers on demand business requirements.

2000 The IFL (specialized Linux processor) is introduced on the zSeries.

2004 The zAAP (Application Assist Processor ) is introduced on the zSeries dedicated to ofload speci ic Java and XML workloads.

2005 IBM zSeries became the IBM Systemz, again as an IBM rebranding.

2006The zIIP (System z Integrated In ormation Processor) is announced or the System z servers. Initially introduced torelieve the general processors (CPs) o speci ic DB2 processing loads, but currently used to ofload other z/OS workloadsas well.

2010Introduction o zEnterprise, zBX and Uni ied Resource Manager (URM): the start o hybrid computing: z/OS, Linux, IBM Power(AIX) and appliances.

2011 Extended hybrid computing with Windows capabilities.

2012IBM Main rame = System z = zEntreprise amily o servers is introduced delivering granularity in the size o servers. With theintroduction o the zEC12 in 2012, ranging rom 26 to 78,000 MIPS on one machine and, at 5.5 GHz, industry leading onprocessor speed or high end servers.

Appendix B. What are MIPS,MSUs and Service Units?Main rames per ormance has traditionally beendescribed in terms o millions o instructionsper second (MIPS), as a simple indication

o speed. This is not as simple as it sounds,because the main rame uses a complexinstruction set, so that the contents and e ecto one instruction can vary enormously.

The dificulty is compounded by actors suchas virtualization and multi processing, and theneed to balance I/O processing with execut iono instructions.

The term MIPS has o ten been parodied asMeaningless Indicator o Processing Speed,but no simple alternative has emerged. Indeed,the emerging market or general purpose utilityand cloud computing su ers rom the lack o a

simple unit o measure equivalent to the MIP.

Within the system, Service Units are used orworkload despatch and balancing. There areapproximately 50 SUs per MIPS.

Separately, the concept o Millions o ServiceUnits (MSUs) arose or aspects such as so twarelicensing. Con usingly, these are not millionso the Service Units measured above: thereare between ive and eight and a hal MIPSper MSU; the igure varies because IBM usesthem to encourage migration tolatest generation main rames.

IBM have tried to acilitate workload estimationand capacity planning by publishing LargeSystem Per ormance Re erence (LSPR) tables,

but these are ar too complex to allowsimple comparisons.

There is an independent analyst, Cheryl Watson,who has made a niche business since 1965 outo publishing charts 10 o the various systemsper ormance or di erent workloads andoperating systems levels, along with Rules oThumb as to how they should be deployed.

10. See System z CPU Chart, www.watsonwalker.com



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About AtosAtos is an international in ormation technologyservices company with annual 2011 pro ormarevenue o EUR 8.5 billion and 74,000 employeesin 48 countries. Serving a global client base, itdelivers hi-tech transactional services, consulting

and technology services, systems integrationand managed services. With its deep technologyexpertise and industry knowledge, it workswith clients across the ollowing market sectors:Manu acturing, Retail, Services; Public, Health &Transports; Financial Services; Telecoms, Media &Technology; Energy & Utilities.

Atos is ocused on business technology thatpowers progress and helps organizations tocreate their firm o the uture. It is the WorldwideIn ormation Technology Partner or the Olympicand Paralympic Games and is quoted on theParis Eurolist Market. Atos operates under thebrands Atos, Atos Consulting & TechnologyServices, Atos Worldline and Atos Worldgrid.

For more in ormation, visit: atos.net

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