Introduction to the new mainframe:Large-Scale Commercial Computing

© Copyright IBM Corp., 2006. All rights reserved.

Chapter 3: Scalability

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Introduction to the new mainframe

© Copyright IBM Corp., 2006. All rights reserved.

Chapter objectives

Upon completion of this chapter the student should be able to understand:• What scalability means• Differences between scaling in and scaling out• Mainframe’s hardware relationship with

scalability• Software scalability levels• Parallel Sysplex relationship with scalability• Workload management main concepts

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Introduction to the new mainframe

© Copyright IBM Corp., 2006. All rights reserved.

Introduction to scalability

Some definitions: Hardware capability of a system to increase

performance under an increased load when resources are added (From Wikipedia Encyclopedia http://en.wikipedia.org/wiki/Scalability)

Software ability to grow with your needs. A scalable software package means that you only buy the parts you need, and that it has the ability to grow by adding on as you grow. (From The Concise Tech Encyclopedia:

http://www.tech-encyclopedia.com/term/scalability)

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Introduction to the new mainframe

© Copyright IBM Corp., 2006. All rights reserved.

Scalability concepts

Scalability approaches

Scale vertically or scale up : add resource to a single node in a system

Scale horizontally or scale out : add nodes to a system

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Introduction to the new mainframe

© Copyright IBM Corp., 2006. All rights reserved.

Scalability concepts

Scalability influences

Vertically growth : Upgrade the installed server processor capacity to a larger one within the same family

Horizontally growth through Parallel Sysplex: add processor capacity by adding more servers in a cluster.

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Introduction to the new mainframe

© Copyright IBM Corp., 2006. All rights reserved.

Scalability influences : be realistic

IBM System z

0

5000

10000

15000

20000

25000

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31

Nways

Rel

ativ

e P

erfo

rman

ce

Sublinear Performance

Linear growth

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Introduction to the new mainframe

© Copyright IBM Corp., 2006. All rights reserved.

Scalability concepts

Provisioning

Provisioning is the end-to-end capability to automatically deploy and dynamically optimize resources in response to business objectives in heterogeneous environments.

helps to respond to changing business

is a critical step to being able to then orchestrate the entire environment to respond to business needs on demand.

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Introduction to the new mainframe

© Copyright IBM Corp., 2006. All rights reserved.

IBM System z implementation – Hardware scalability

System I/O Bandwidth

CPUs

GBs ITRs for 1-way

System z9 109*

zSeries 990zSeries 900

Generation 6Generation 5

172.8 GB/sec

96 GB/sec

24 GB/sec

256 GB 64 GB 288.15 450 ~ 600

16-way

32-way

54-way

512 GB

Balanced SystemCPU, nWay,

Memory,I/O Bandwidth*

*z9-109 exploits a subset of its designed I/O capabilityITR = Internal Throughput Rate

ITR =Unit of Work

Processor busy timeITR =

Unit of Work

Processor busy time

Unit of Work

Processor busy time

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Introduction to the new mainframe

© Copyright IBM Corp., 2006. All rights reserved.

IBM System z processorsZ9 Model 38 Configuration

1 GB/sec 500 MB/sec 333 MB/sec Speed set

based on I/O type

Processor Book 3

FICON Express2

I/O Ports

OSA-Express2

I/O Ports

STIs @ 2.7 GB/sec

Memory Cards

L2 Cache

16 STIs

PU PU PU PU

PU PU PU PU

Memory Cards

L2 Cache

16 STIs

PU PU PU PU

PU PU PU PU

Ring Structure

8 MBA Fanout

Processor Book 0

I/O Card

Processor Book 1

ESCON

I/O Ports

Crypto Express2

ICB-42 GB/sec

Memory Cards

L2 Cache

16 STIs

PU PU PU PU

PU PU PU PU

Memory Cards

L2 Cache

16 STIs

PU PU PU PU

PU PU PU PU

Ring Structure

Processor Book 2

8 MBA Fanout 8 MBA Fanout 8 MBA Fanout

Note: Each MBA Fanout card has 2 STI ports. STI connectivity is normally balanced across all installed BooksMBA supports 2 GB/sec for ICB3 and ICB-4 and 2.7 GB/sec for I/O channels. ICB-3 actually run at

1GB/sec

STI-MP&

STI-A8

STI-MP&

STI-A8

STI-MP&

STI-A8

STI-MP&

STI-A8

STI-MP&

STI-A8

STI-MP&

STI-A8

STI-MP&

STI-A8

STI-MP&

STI-A8

I/O Cage I/O Cage

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Introduction to the new mainframe

© Copyright IBM Corp., 2006. All rights reserved.

Operating system scalability

z/OS Structurez/OS Structure

InteractiveSystemUsers

Base Operating System

User

User

User

User

DB2

Batch Control

Domino

LIC (LPAR, etc)

zSeries hardware

User

User

User

User

User

User

User

User

WEB-SPHERE

InteractiveTrans. Users

InteractiveTrans. Users

TCP/IP

Network Support

A d d r e s s S p a c e s

SystemTask

BatchJob

BatchJob

BatchJob

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Introduction to the new mainframe

© Copyright IBM Corp., 2006. All rights reserved.

Scalability of IBM System z – Parallel Sysplex

ESCON/FICON

Coupling Facility

SYSPLEX Timer

Shared Data

Z9 BC

Z9 EC

Z9 EC

Z9 BC

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Introduction to the new mainframe

© Copyright IBM Corp., 2006. All rights reserved.

Parallel Sysplex

Serialization : to coordinate access to resources

• Enqueuing : serialization for a large number of resource

• Locking : extremely quick, but only for a small number of resources

Communication : Cross-System coupling facility provides simplified multisystep management services withjin a base sysplex configuration

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Introduction to the new mainframe

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Parallel Sysplex (Cont...)

Data sharing and Coupling facility

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Introduction to the new mainframe

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Parallel Sysplex (Cont...)

Workload distribution Manually

Round robin

Dynamic workload distribution

Workload Management-driven application servers

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Introduction to the new mainframe

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Provisioning

Dynamic Resource Distribution Up to 60 logical partitions (LPAR) Each LPAR is completely isolated and protected Processors can be shared Workload Manager (WLM) can distributed processing resources

across LPAR clusters I/O bandwith can be shared amongs LPARs under WLM control Each LPAR has own physical memory, it can be altered

dynamically

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Introduction to the new mainframe

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Capacity On Demand (CoD)

Different CoD options: Capacity Upgrade on Demand (CUoD) Customer Initiated Upgrade (CIU) On/Off Capacity on Demand

CoD encompasses the various capabilities for you o dynamically activate one or more resources in your server as your business peaks dictate.

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Introduction to the new mainframe

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Workload Manager (WLM)

The idea of Workload Manager is to make a contract between the installation (end user) and the operating system. The installation classifies the work running on the z/OS operating system in distinct service classes and defines goals for them which express the expectation how the work should perform. WLM uses these goal definitions to manage the work across all systems of a parallel sysplex environment.

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Introduction to the new mainframe

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WLM Components

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Introduction to the new mainframe

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WLM (Cont...)

Work unit identification Managing Units of Work on z/OS (e.g. A transaction)

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Introduction to the new mainframe

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WLM (Cont...)

Defining the service level Importance of a goal Adjustment routine Workload Management controls

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Introduction to the new mainframe

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WLM (Cont...)

WLM extensions

Intelligent Resource Director (IRD) CPU LPAR management Dynamic channel path management I/O Priority

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Introduction to the new mainframe

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Summary

The New Mainframe:• is scalable• On hardware and software level• Parallel Sysplex is involved• WLM

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Introduction to the new mainframe

© Copyright IBM Corp., 2006. All rights reserved.

Key terms in this chapter

• Access time• CF• CoD• Communication• Coupling facility• Enqueuing• IRD• ITR• Locking

• LPAR• Parallel Sysplex• Provision • Scalability • Scale in • Scale out• Serialization• SLA• WLM • Workload