Introduction to the new mainframe: z/OS basics
Chapter 1: The new mainframe
© Copyright IBM Corp., 2011. All rights reserved.
Redbook Copy
Smarter …
… systems
… software
… storage
… services
Introduction to the new mainframe
Chapter 1 objectives
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.
© Copyright IBM Corp., 2011. All rights reserved.
Introduction to the new mainframe
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."
© Copyright IBM Corp., 2011. All rights reserved.
Introduction to the new mainframe
The Mainframe Charter – Providing a Strategic Framework
It is our intention to…
Innovation
Value
Community
• Provide leadership in
• Enhance the value
• Support programs
innovation to enhance the
use of the IBM mainframe
to support increasingly
integrated and flexible
business processes for
the On Demand
Business.*
proposition and lower the
cost of computing of
mainframe solutions in a
way that is compelling,
clear, and consistent.*
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
© Copyright IBM Corp., 2011. All rights reserved.
Introduction to the new mainframe
z/OS Innovation –
Redefining the mainframe for 5 decades!
HW
S/360
1964
MVT, PCP
MFT
VSE
S/370
S/370XA – 31 bits
1970
1980
MVS – VTAM
VM
CMOS –
Parallel Sysplex
ESA/390
1990
MVS/XA
SW
Unix System Services
TCP/IP
ServerPac,
IMS CICS
DB2
zAAP zIIP EAV
2000
MVS/ESA
OS/390
VSE/ESA
zEnterprise
and zBX
z/Architecture – 64 bits
2010
z/OS
z/VM
z/VSE
WebSphere
Linux
Unicode
Java
Appliances
Optimizers
z/OSMF
XML
Model z196
© Copyright IBM Corp., 2011. All rights reserved.
zBX
Introduction to the new mainframe
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
© Copyright IBM Corp., 2011. All rights reserved.
Introduction to the new mainframe
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
© Copyright IBM Corp., 2011. All rights reserved.
zBX
Introduction to the new mainframe
Mainframe Attributes:
• 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
Model z196
© Copyright IBM Corp., 2011. All rights reserved.
zBX
Introduction to the new mainframe
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
© Copyright IBM Corp., 2011. All rights reserved.
zBX
Introduction to the new mainframe
Who uses mainframe computers?
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
Z196: Each PU chip
has up to four cores
running at 5.2 GHz,
which means a 0.19
ns cycle time.
Business Class (BC)
Enterprise Class (EC)
© Copyright IBM Corp., 2011. All rights reserved.
Introduction to the new mainframe
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
© Copyright IBM Corp., 2011. All rights reserved.
zBX
Introduction to the new mainframe
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
© Copyright IBM Corp., 2011. All rights reserved.
Introduction to the new mainframe
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.
© Copyright IBM Corp., 2011. All rights reserved.
Introduction to the new mainframe
Typical batch use
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.
© Copyright IBM Corp., 2011. All rights reserved.
Introduction to the new mainframe
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?
© Copyright IBM Corp., 2011. All rights reserved.
Introduction to the new mainframe
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
© Copyright IBM Corp., 2011. All rights reserved.
Introduction to the new mainframe
Typical online use
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.
© Copyright IBM Corp., 2011. All rights reserved.
Introduction to the new mainframe
Speciality engines to characterize workload
z/OS LPAR
WAS
zAAP
Application
TCP/IP
HiperSockets
z/OS LPAR
DRDA
DB2
Application
WAS
Application
not on
System z
Application
TCP/IP
D
R
D
A
Star
Schema
zAAP
All of the IBM
System z specialty
engines can operate
on the same
machine together
CP
zIIP
DRDA
TCP/IP
HiperSockets
Linux on
System z LPAR
Application
IFL
ICF
© Copyright IBM Corp., 2011. All rights reserved.
Introduction to the new mainframe
The zIIP and the zAAP
The 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
© Copyright IBM Corp., 2011. All rights reserved.
Introduction to the new mainframe
System z Concurrent Upgrade – Customer Controlled
• 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
Note: Upgrades are non-disruptive only where there is sufficient hardware resource available and provided pre-planning has been done
© Copyright IBM Corp., 2011. All rights reserved.
Introduction to the new mainframe
© Copyright IBM Corp., 2011. All rights reserved.
Introduction to the new mainframe
Mainframe Operating System Heritage
OS/360 -> OS/VS -> MVS/SP -> MVS/XA -> MVS/ESA -> OS/390 -> z/OS
z/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 online 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/VM
z/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.
© Copyright IBM Corp., 2011. All rights reserved.
Introduction to the new mainframe
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 start
to replace individual islands of computing and that can work to reduce complexity,
improve security, and bring applications closer to the data they need.
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).
xHyp = Hypervisor for System x
pHyp = Hypervisor for System p
PR/SM = Processor Resource Systems Manager
SE = Support Element
AMM = Advance Management Module
ISS = Integrated Support Services
DP = Data Power
HPC = High Performance Computing
DWA = Data Warehouse Acceleration
Model z196
© Copyright IBM Corp., 2011. All rights reserved.
zBX
Introduction to the new mainframe
zEnterprise Value Proposition
Networking
Workloads
Workloads
Networking
Workloads
Workloads
Networking
Fit for Purpose minimizes
cost of acquisition and
preserves quality of service
Centralized platform and
structured practices minimize
labor costs
© Copyright IBM Corp., 2011. All rights reserved.
25
Introduction to the new mainframe
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
© Copyright IBM Corp., 2011. All rights reserved.
zBX
Introduction to the new mainframe
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.
© Copyright IBM Corp., 2011. All rights reserved.
Introduction to the new mainframe
1.14 Topics for further discussion
Here 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.
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.
© Copyright IBM Corp., 2011. All rights reserved.