1. Click to add text Introduction to the new mainframe: Large-Scale Commercial Computing © Copyright IBM Corp., 2006. All rights reserved. Chapter 3: Scalability

2. Introduction to the new mainframe © Copyright IBM Corp., 2006. All rights reserved. 2 Objectives The student should be able to understand: What scalability means Differences between scaling in and scaling out Mainframe’s hardware scalability Software scalability levels Parallel Sysplex relationship with scalability Workload management main concepts

3. Introduction to the new mainframe © Copyright IBM Corp., 2006. All rights reserved. 3 Introduction to scalability Definitions:  Hardware capability to increase performance when resources are added  Software ability to grow with your needs. Scalable software means you only buy what you need, and add as you grow.

4. Introduction to the new mainframe © Copyright IBM Corp., 2006. All rights reserved. 4 Scalability concepts  Scalability approaches Scale vertically or scale up : add resource to a single node Scale horizontally or scale out : add nodes e.g add SMP processors

5. Introduction to the new mainframe © Copyright IBM Corp., 2006. All rights reserved. 5 Scalability concepts  Scalability influences Vertically growth : - Upgrade the processor within the same family - Add memory or channels Horizontally growth through Parallel Sysplex: - Add processor capacity by adding servers in a cluster.

6. Introduction to the new mainframe © Copyright IBM Corp., 2006. All rights reserved. 6 Scalability influences : be realistic IBM System z 0 5000 10000 15000 20000 25000 13579 1113 15 171921 2325 272931 Nways Relative Performance Sublinear Performance Linear growth

7. Introduction to the new mainframe © Copyright IBM Corp., 2006. All rights reserved. 7 Scalability concepts Provisioning: The capability to -automatically deploy and -dynamically optimize resources in response to business objectives  helps to respond to changing business  is a critical step to change the environment to respond to business needs.

8. Introduction to the new mainframe © Copyright IBM Corp., 2006. All rights reserved. 8 IBM System z implementation – Hardware scalability System I/O Bandwidth CP Us GBs ITRs for 1-way System z9 109* zSeries 990 zSeries 900 Generation 6 Generation 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 System CPU, nWay, Memory, I/O Bandwidth* *z9-109 exploits a subset of its designed I/O capability ITR = Internal Throughput Rate

9. Introduction to the new mainframe © Copyright IBM Corp., 2006. All rights reserved. 9 Operating system scalability

10. Introduction to the new mainframe © Copyright IBM Corp., 2006. All rights reserved. 10 Scalability of IBM System z – Parallel Sysplex ESCON/FICON Coupling Facility SYSPLEX Timer Shared Data Z9 BC Z9 EC Z9 BC

11. Introduction to the new mainframe © Copyright IBM Corp., 2006. All rights reserved. 11 Parallel Sysplex  Serialization : to coordinate access to resources Enqueuing : serialization for a large number of resources Locking : extremely quick, but only for a small number of resources  Communication : Cross-System coupling facility provides simplified management services within a sysplex configuration

12. Introduction to the new mainframe © Copyright IBM Corp., 2006. All rights reserved. 12 Parallel Sysplex (Cont...)  Data sharing and Coupling facility

13. Introduction to the new mainframe © Copyright IBM Corp., 2006. All rights reserved. 13 Parallel Sysplex (Cont...)  Workload distribution Manually Round robin Dynamic workload distribution Workload Management-driven application servers

14. Introduction to the new mainframe © Copyright IBM Corp., 2006. All rights reserved. 14 Provisioning  Dynamic Resource Distribution Up to 60 logical partitions (LPAR) Each LPAR is completely isolated and protected Processors can be shared beween LPARs Workload Manager (WLM) can distribute 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

15. Introduction to the new mainframe © Copyright IBM Corp., 2006. All rights reserved. 15 Capacity On Demand (CoD) Different CoD options:  Capacity Upgrade on Demand (CUoD)  Customer Initiated Upgrade (CIU)  On/Off Capacity on Demand CoD provides capabilities to dynamically activate one or more resources as business peaks dictate.

16. Introduction to the new mainframe © Copyright IBM Corp., 2006. All rights reserved. 16 Workload Manager (WLM) The Workload Manager: Make a contract between the installation and the operating system. -The installation classifies the work into distinct service classes and then -defines goals for the classes that express how the work should perform. WLM uses these goals to manage the work across all systems of a parallel sysplex environment.

17. Introduction to the new mainframe © Copyright IBM Corp., 2006. All rights reserved. 17 WLM (Cont...)  Work unit identification Managing Units of Work on z/OS (e.g. A transaction)

18. Introduction to the new mainframe © Copyright IBM Corp., 2006. All rights reserved. 18 WLM (Cont...)  Defining the service level Importance of a goal Adjustment routine e.g. how fast to react Workload Management controls

19. Introduction to the new mainframe © Copyright IBM Corp., 2006. All rights reserved. 19 WLM (Cont...)  WLM extensions  Intelligent Resource Director (IRD) CPU LPAR management Dynamic channel path management I/O Priority

20. Introduction to the new mainframe © Copyright IBM Corp., 2006. All rights reserved. 20 Summary The Mainframe: is scalable On both hardware and software level Parallel Sysplex is involved Work Load Manager (WLM)