introduction to the new mainframe: z/os basics © copyright ibm corp., 2011. all rights reserved....

Introduction to the new mainframe: z/OS basics

© Copyright IBM Corp., 2011. All rights reserved.

Chapter 1: The new mainframe

Smarter … … systems … software … storage … services

Redbook Copy

Introduction to the new mainframe


After completing this chapter, you will be able to:• List ways in which the mainframes of today challenge the traditional thinking about

centralized computing versus distributed computing.• Explain how businesses make use of mainframe processing power, the

typical uses of mainframes, and how mainframe computing differs from

other types of computing.• Outline the major types of workloads for which mainframes are best suited.• Name five jobs or responsibilities that are related

to mainframe computing.• Identify four mainframe operating systems.• Describe how IBM zEnterprise System is used

to address IT problems.

Chapter 1 objectives



7th April 1964, Poughkeepsie NY

A new generation of electronic computing equipment was introduced today by International Business Machines Corporation. IBM Board Chairman Thomas J. Watson Jr. called the event the most important product announcement in the company's history.

The new equipment is known as the IBM System/360.

"System/360 represents a sharp departure from concepts of the past in designing and building computers. It is the product of an international effort in IBM's laboratories and plants and is the first time IBM has redesigned the basic internal architecture of its computers in a decade. The result will be more computer productivity at lower cost than ever before. This is the beginning of a new generation - - not only of computers - - but of their application in business, science and government."



The Mainframe Charter – Providing a Strategic Framework

Innovation

• Provide leadership in

innovation to enhance

the use of the IBM

mainframe to support

increasingly integrated

and flexible business

processes for the On

Demand Business.*

It is our intention to…

Value

• Enhance the value

proposition and lower the

cost of computing of

mainframe solutions in a

way that is compelling,

clear, and consistent.*

Community

• Support programs

designed to foster vitality

in the IBM mainframe

community, helping to

promote a strong

application portfolio and

world-class support

services.*

* Excerpted from the Mainframe Charter – August 2003



z/OS Innovation – Redefining the mainframe for 5 decades!

HW S/360 S/370 S/370XA – 31 bits ESA/390 CMOS –

Parallel Sysplex

1964 1970 1980 1990 2000 2010

zEnterpriseand zBX

SW

MVT, PCPMFT

VSE

MVS – VTAM MVS/XA z/OS VM z/VM z/VSE

MVS/ESAOS/390

VSE/ESA

Unix System ServicesTCP/IP

Appliances Optimizers

IMS CICS DB2 Linux WebSphere

zAAP zIIP EAV

z/Architecture – 64 bits

z/OSMFServerPac, Unicode Java XML

Model z196 zBX



Mainframes in our midst

Mainframes:

• Are prevalent, yet hidden from public eye• Not often publicized – stable, reliable, dependable.• Contrast with other forms of computing, such as PCs.• Present opportunities for college graduates in a variety of technical fields.• Exploits hybrid computing capabilities for centralized business requirements



What is a mainframe?

• A mainframe is a computing system that businesses use to host the commercial databases, transaction servers, and applications that require a greater degree of security and availability than is commonly found on smaller-scale machines.

• The power of a mainframe provides computing speed and capacity, enabling it to perform high volumes of processing.

• The mainframe can process a mixed workload of jobs from different time zones and of different types concurrently.

• The mainframe offers optional appliances to offload workload to

optimize throughput and cost savings.

Model z196 zBX



Mainframe Attributes:

Model z196 zBX

• Compatibility with System z operating systems, applications, and data.

• Centralized control of resources.• Hardware and operating systems that can share access to disk drives

with other systems, with automatic locking and protection against destructive simultaneous use of disk data.

• A style of operation, often involving dedicated operations staff who use detailed operations procedure books and highly organized procedures for backups, recovery, training, and disaster recovery at an alternative location.

• Hardware and operating systems that routinely work with hundreds or thousands of simultaneous I/O operations.• Hybrid workload computing



Mainframe facts

• Who uses mainframes?• Most Fortune 1000 companies use a mainframe

environment • 60% of all data available on the Internet is stored on

mainframe computers• Why mainframes?

• Large-scale transaction processing • Thousands of transactions per second

• Support thousands of users and application programs • Simultaneously accessing resources• Terabytes of information in databases• Large-bandwidth communications

Model z196 zBX



Businesses today rely on the mainframe to:

• Perform large-scale transaction processing (thousands of transactions per second)

• Support thousands of users and application programs concurrently accessing numerous resources

Who uses mainframe computers?

Business Class (BC) Enterprise Class (EC)

Z196: Each PU chiphas up to four coresrunning at 5.2 GHz, which means a 0.19 ns cycle time.



Factors contributing to mainframe use

The reasons for mainframe use are many, but most generally fall into one or

more of the following categories:

• Reliability, availability, and serviceability (RAS)

• Security

• Scalability

• Continuing compatibility

• Evolving architecture

• Extensibility

• Total cost of ownership

• Environment friendly

Model z196 zBX



Typical mainframe workloads

While batch processing is possible on distributed systems, it is not as commonplace as it is on mainframes because distributed systems often lack:

• Sufficient data storage• Available processor capacity, or cycles• Sysplex-wide management of system resources and job scheduling



While batch processing is possible on distributed systems, it is not as commonplace as it is on mainframes because distributed systems often lack:

• Sufficient data storage• Available processor capacity, or cycles• Sysplex-wide management of system resources and job scheduling• Strong I/O subsystem

Batch processes typically have the following characteristics:• Large amounts of input data are processed and stored (perhaps terabytes or more), large numbers of records are accessed, and a large volume of output is produced.• Immediate response time is usually not a requirement. However, batch jobs often must complete within a “batch window,” a period of less-intensive online activity, as prescribed by a service level agreement (SLA).• Information is generated about large numbers of users or data entities (for example, customer orders or a retailer’s stock on hand).• A scheduled batch process can consist of the execution of hundreds or thousands of jobs in a pre-established sequence.



1. At night, numerous batch jobs running programs and utilities are processed. These jobs consolidate the results of the online transactions that take place during the day.

2. The batch jobs generate reports of business statistics.

3. Backups of critical files and databases are made before and after the batch window.

4. Reports with business statistics are sent to a specific area for analysis the next day.

5. Reports with exceptions are sent to the branch offices.

6. Monthly account balance reports are generated and sent to all bank customers.

7. Reports with processing summaries are sent to the partner credit card company.

8. A credit card transaction report is received from the partner company.

9. In the production control department, the operations area is monitoring the messages on the system console and the execution of the jobs.

10.Jobs and transactions are reading or updating the database (the same one that is used by online transactions) and many files are written to tape.

Attention: Today’s mainframe can run standard batch processing such as COBOL as well as UNIX and Java programs. These runtimes can execute either as standalone or participate collaboratively within a single jobstream. This makes batch processing extremely flexible integrating different execution environments centrally on a single server.

Typical batch use



Online transactions are familiar to most people - Examples include:• ATM machine transactions such as deposits, withdrawals, inquiries, and transfers• Supermarket payments with debit or credit cards• Purchase of merchandise over the Internet For example, inside a bank branch office or on the Internet, customers are using online services when checking an account balance or directing fund balances.

In fact, an online system performs many of the same functions as an operating system:

• Managing and dispatching tasks• Controlling user access authority to system resources• Managing the use of memory• Managing and controlling simultaneous access to data files • Providing device independence

How might the end users in these industries interact with their mainframe systems?

• Multiple factors can influence the design of a company’s transaction processing system, including:• Number of users interacting with the system at any one time.• Number of transactions per second (TPS).• Availability requirements of the application. For example, must the application be available 24 hours a day, seven days a week, or can it be brought down briefly one night each week?



Online transactions usually have the following characteristics:

• A small amount of input data, a few stored records accessed and processed, and a small amount of data as output

• Immediate response time, usually less than one second

• Large numbers of users involved in large numbers of transactions

• Round-the-clock availability of the transactional interface to the user

• Assurance of security for transactions and user data

• Logging and journaling for backup and recovery



1. A customer uses an ATM, which presents a user-friendly interface for various functions: withdrawal, query account balance, deposit, transfer, or cash advance from a credit card account.

2. Elsewhere in the same private network, a bank employee in a branch office performs operations, such as consulting, working with fund applications, and money ordering.

3. At the bank’s central office, business analysts tune transactions for improved performance. Other staff use specialized online systems for office automation to perform customer relationship management, budget planning, and stock control.

4. All requests are directed to the mainframe computer for processing.

5. Programs running on the mainframe computer perform updates and inquiries to the database management system (for example, DB2).

6. Specialized disk storage systems store the database files.

Typical online use



Speciality engines to characterize workload

z/OS LPAR

Application

Applicationnot on

System zTCP/IP

All of the IBM System z specialty

engines can operate on the same

machine together

Linux on System z LPARApplication

IFL

TCP/IPHiperSockets

DRDA

DB2

CP

z/OS LPARWAS Application

zAAP

TCP/IPHiperSockets

WASApplication

zAAP

zIIP

DRDA

DRDA

StarSchema

ICF



The zIIP and the zAAPThe zIIP and the zAAPThe zIIP is a chip that's really hip.The MIP on a zIIP is not charged full clip.The zIIP (like the zAAP) will benefit the app.The zIIP and the zAAP will make pricing a snap.

by Dr. zEUSS



• On/Off Capacity on Demand - Temporary upgrade • Non-disruptive temporary addition of CPs, IFLs, ICFs zAAPs and zIIPs • Upgrades requiring parts (e.g., for a z9 EC Model S08 to S18 upgrade) not supported• "Right to use" feature - Orderable as MES or with new build to initiate contract and administrative

setup• Customer orders and installs upgrade via Resource Link and IBM RSF• Non-disruptive removal when capacity is no longer wanted

• Break even point is 90 days

• CIU – Customer Initiated Upgrade - Express - Permanent upgrade• Customer capability to order and install permanent upgrade• Not included

• Upgrades requiring parts (e.g., for a z9 EC Model S08 to S18 upgrade) • Channel upgrades by LIC enable of existing ports

• CIU feature - MES ordered to initiate contract and administrative setup• Customer orders and installs upgrade via Resource Link and IBM RSF

• CBU – Capacity BackUp - Temporary emergency capacity upgrade• Non-disruptive temporary addition of CPs, IFL, ICF, zAAPs, zIIPs in an emergency situation • CBU contract required to order CBU features and CBU LIC CC• Customer activates upgrade for test or temporary emergency• Concurrent downgrade after test or recovery completed

System z Concurrent Upgrade – Customer Controlled

Note: Upgrades are non-disruptive only where there is sufficient hardware resource available and provided pre-planning has been done



Mainframe Operating System Heritage

OS/360 -> OS/VS -> MVS/SP -> MVS/XA -> MVS/ESA -> OS/390 -> z/OSz/OS is IBM’s premier zSeries operating system, is a highly secure, scalable, high-performance enterprise operating system on which to build and deploy traditional and Java-enabled applications, providing a comprehensive and diverse application execution environment.

DOS/360 -> DOS/VS -> VSE/SP -> VSE/ESA -> z/VSE VSE enables proven, robust, and cost-effective solutions. VSE provides sturdy batch and industrial strength on-line transaction processing (CICS) capabilities. VSE can fit comfortably into a legacy of thrifty, dependable VSE solutions.

ACP -> TPF-> z/TPF

TPF is the platform driving the business-critical systems for many of IBM's largest and most sophisticated users of online transaction processing - airlines, railroads, hotels, financial services, government, credit card and banking industries.

CP/67 -> VM/370 -> VM/SP -> VM/XA -> VM/ESA -> z/VMz/VM provides a highly flexible test and production environment for enterprises deploying the latest e-business solutions. z/VM helps enterprises meet their growing demands for multi-user server solutions with support for a broad range of operating systems.



Introducing the IBM zEnterprise System

For the first time it is possible to deploy an integrated hardware platform that brings mainframe and distributed technologies together, producing a system that can startto replace individual islands of computing and that can work to reduce complexity, improve security, and bring applications closer to the data they need.

Model z196 zBX

xHyp = Hypervisor for System xpHyp = Hypervisor for System pPR/SM = Processor Resource Systems ManagerSE = Support ElementAMM = Advance Management ModuleISS = Integrated Support ServicesDP = Data PowerHPC = High Performance ComputingDWA = Data Warehouse Acceleration

ENSEMBLE – A collection of one or more zEnterprise nodes (including any attached zBX) that are managed as a single logical virtualized system by the Unified Resource Manager, through the use of a Hardware Management Console (HMC).



zEnterprise Value Proposition

Fit for Purpose minimizes cost of acquisition and

preserves quality of service

Centralized platform and structured practices minimize

labor costs

Workloads

WorkloadsWorkloads

25

Workloads

Networking

Networking

Networking



Summary

The New Mainframe:

• Plays a central role in the daily operations of the world’s largest organizations – and the daily lives of most people.

• Is known for its reliability, security, and enormous processing capabilities.

• Is designed for processing large scale workloads and serving thousands of

users and transactions concurrently.

• Is managed by highly skilled technical support staff.

• Runs a variety of operating systems.

• Can execute hybrid and complex transaction types.

Model z196 zBX



1.13 Questions for review

To help test your understanding of the material in this chapter, perform the following tasks:

1. List ways in which the mainframe of today challenges the traditional thinking about centralized computing versus distributed computing.2. Explain how businesses make use of mainframe processing power, and how mainframe computing differs from other types of computing.3. List some of the factors that contribute to mainframe use.4. List three strengths of mainframe computing, and outline the major types of workloads for which mainframes are best suited.5. Name five jobs or responsibilities that are related to mainframe computing.6. This chapter mentioned at least five operating systems that are used on the mainframe. Choose three of them and describe the main characteristics of each one.



4. What characteristics, good or bad, exist in a mainframe processing environment because of the roles that are present in a mainframe shop? (Efficiency? Reliability? Scalability?)5. Describe some similarities and differences between application development for mainframe systems compared to other systems.6. Most mainframe shops have implemented rigorous systems management, security, and operational procedures. Have these same procedures been implemented in distributed system environments? Why or why not?7. Can you find examples of mainframe use in your everyday experiences? Describe them and the extent to which mainframe processing is apparent to users. Examples might include the following: a. Popular websites that rely on mainframe technology as the back-end server to support online transactions and databases. b. Multitiered applications that interface with mainframe resources. c. Mainframes used in your locality. These might include banks and financial centers, major retailers, transportation hubs, and the health and medical industries.8. Can you find examples of distributed systems in everyday use? Could any of these systems be improved through the addition of a mainframe? How?9. How is today’s mainframe environment-friendly? Discuss with examples.

1.14 Topics for further discussionHere are topics for further discussion:

1. What is a mainframe today? How did the term arise? Is it still appropriate?2. Why is it important to maintain system compatibility for older applications? Why not simply change existing application programming interfaces whenever improved interfaces become available?3. Describe how running a mainframe can be cost effective, given the large number of roles needed to run a mainframe system.

introduction to the new mainframe: z/os basics © copyright ibm corp., 2011. all rights reserved....

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