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Considerations for Transitioning Highly Available Applications to System z

Book Description

You may have several triggers to investigate the feasibility of moving a workload or set of workloads to the IBM® System z® platform. These triggers could be concerns about operational cost, manageability, or delivering the agreed service levels, among others.

Investigating the feasibility of a possible migration or transition to any other platform, including System z, requires a number of basic steps. These steps usually start with an understanding of the current workload and its pain points, and end with a business case to move the workload. It is important to find out how easy a migration is going to be and how much risk will be involved.

In this IBM Redbooks® publication we offer thoughts on how to move through these steps. We also include a chapter with a System z technology summary to help you understand how a migrated workload may fit on the platform.

Our focus in this book is on workloads that are mission-critical and require a high level of availability, including disaster recovery.

Table of Contents

  1. Front cover
  2. Notices
    1. Trademarks
  3. Preface
    1. The team who wrote this book
    2. Now you can become a published author, too!
    3. Comments welcome
    4. Stay connected to IBM Redbooks
  4. Chapter 1. Management summary
  5. Chapter 2. Introduction to systems availability
    1. 2.1 Introduction
    2. 2.2 Availability concepts
      1. 2.2.1 High availability
      2. 2.2.2 Continuous operation
      3. 2.2.3 Continuous availability
      4. 2.2.4 Business impact of outages
    3. 2.3 Evaluating availability
      1. 2.3.1 Key availability issues
      2. 2.3.2 Causes of service outage
      3. 2.3.3 Service Level Agreement (SLA)
      4. 2.3.4 Service request failure
    4. 2.4 Other system availability measures
    5. 2.5 Designing for availability
      1. 2.5.1 Elements of a continuously available service
      2. 2.5.2 Failing over to another site and using moderate quality components, or not
      3. 2.5.3 Surviving component failure with redundancy
    6. 2.6 Summary
  6. Chapter 3. Target architectures for availability
    1. 3.1 Target reference architectures
      1. 3.1.1 Each site
      2. 3.1.2 Activity levels for two-site deployments
      3. 3.1.3 Information replication between sites
      4. 3.1.4 Multisite deployment
      5. 3.1.5 Summary
    2. 3.2 Factors that influence the approach to take on the target architecture
      1. 3.2.1 Non-functional requirements
      2. 3.2.2 Fit for purpose
      3. 3.2.3 Cost of the target architecture
      4. 3.2.4 Risk
      5. 3.2.5 Business requirements
      6. 3.2.6 Mapping source architecture to target architecture
      7. 3.2.7 Common terminology
    3. 3.3 Integration with external services
  7. Chapter 4. System z technology options
    1. 4.1 Operating systems
      1. 4.1.1 z/OS
      2. 4.1.2 z/VM
      3. 4.1.3 Linux on System z
      4. 4.1.4 Important decisions with respect to operating systems
    2. 4.2 Virtualization
      1. 4.2.1 Mainframe virtualization technologies
      2. 4.2.2 PR/SM and logical partitioning
      3. 4.2.3 z/VM
      4. 4.2.4 Address spaces in z/OS
      5. 4.2.5 Enclaves on z/OS
      6. 4.2.6 Important decisions with respect to virtualization
    3. 4.3 Resource management
    4. 4.4 Workload management
      1. 4.4.1 Workload management under z/OS
      2. 4.4.2 Workload management under z/VM
    5. 4.5 Network and communications
      1. 4.5.1 Support of legacy protocols
      2. 4.5.2 Server load distribution
      3. 4.5.3 System z network connectivity
      4. 4.5.4 z/VM virtual networking
      5. 4.5.5 Important decisions with respect to communications
    6. 4.6 Availability and scalability
      1. 4.6.1 Availability
      2. 4.6.2 Disaster recovery
      3. 4.6.3 What about planned outages
      4. 4.6.4 Parallel Sysplex
      5. 4.6.5 High availability solutions for data
      6. 4.6.6 Storage resilience considerations
      7. 4.6.7 Scalability
      8. 4.6.8 Important decisions with respect to availability and scalability
    7. 4.7 Security
      1. 4.7.1 Security in z/OS
      2. 4.7.2 Security in z/VM and Linux on System z
      3. 4.7.3 Important decisions with respect to security
    8. 4.8 Transaction management
      1. 4.8.1 Running programs in a transaction manager or not
      2. 4.8.2 Important decisions with respect to transaction management
    9. 4.9 Data management
      1. 4.9.1 Database management systems
      2. 4.9.2 Highly available file systems
      3. 4.9.3 Important decisions with respect to data management
    10. 4.10 Programming environment
      1. 4.10.1 Java on System z
      2. 4.10.2 COBOL and PL/I
      3. 4.10.3 C/C++
      4. 4.10.4 Application development tooling
      5. 4.10.5 Important decisions with respect to programming environment
    11. 4.11 Integration
      1. 4.11.1 Integration layers
      2. 4.11.2 Integration styles
    12. 4.12 Systems management
      1. 4.12.1 Availability and performance management
      2. 4.12.2 Capacity management and sizing
      3. 4.12.3 Security management
      4. 4.12.4 Service level management
      5. 4.12.5 Problem and change management
      6. 4.12.6 Configuration management
      7. 4.12.7 Release management
      8. 4.12.8 Storage management
      9. 4.12.9 Service continuity management
      10. 4.12.10 Incident management
      11. 4.12.11 Asset and financial management
    13. 4.13 Specialty processors
  8. Chapter 5. Operational models for high availability
    1. 5.1 Introduction
      1. 5.1.1 Planned outages
      2. 5.1.2 A word on scalability and capacity
    2. 5.2 Single-site Parallel Sysplex
      1. 5.2.1 Model description
      2. 5.2.2 Availability characteristics
      3. 5.2.3 Functionality
      4. 5.2.4 Availability scenario
    3. 5.3 Single-site Parallel Sysplex with two servers and disk-levelreplication (basic Hyperswap)
      1. 5.3.1 Model description
      2. 5.3.2 Availability characteristics
      3. 5.3.3 Functionality
      4. 5.3.4 Availability scenario
    4. 5.4 Dual site with data replication
      1. 5.4.1 Model description
      2. 5.4.2 Availability characteristics
      3. 5.4.3 Functionality
      4. 5.4.4 Availability scenario
    5. 5.5 Dual-site Parallel Sysplex with data-level replication (active/passive)
      1. 5.5.1 Model description
      2. 5.5.2 Availability characteristics
      3. 5.5.3 Functionality
      4. 5.5.4 Availability scenario
    6. 5.6 Dual-site Parallel Sysplex with disk-level replication (Metro Mirror)
      1. 5.6.1 Model description
      2. 5.6.2 Availability characteristics
      3. 5.6.3 Functionality
      4. 5.6.4 Availability scenario
    7. 5.7 Dual-site Parallel Sysplex with disk-level replication (Global Mirror)
      1. 5.7.1 Model description
      2. 5.7.2 Availability characteristics
      3. 5.7.3 Functionality
      4. 5.7.4 Availability scenario
    8. 5.8 Linux on System z - Linux HA
      1. 5.8.1 Model description
      2. 5.8.2 Availability characteristics
      3. 5.8.3 Functionality
      4. 5.8.4 Availability scenario
    9. 5.9 Linux on z - GDPS
      1. 5.9.1 Model description
      2. 5.9.2 Availability characteristics
      3. 5.9.3 Functionality
      4. 5.9.4 Availability scenario
    10. 5.10 Model summary
  9. Chapter 6. Workload assessment
    1. 6.1 Workload assessment overview
      1. 6.1.1 Workload tiers
      2. 6.1.2 Domains of Transformation
      3. 6.1.3 Availability and scalability assessment
      4. 6.1.4 Integration assessment
      5. 6.1.5 Middleware assessment
      6. 6.1.6 Database and file systems
      7. 6.1.7 Security assessment
      8. 6.1.8 Systems management assessment
      9. 6.1.9 Capacity
    2. 6.2 Completing the assessment
      1. 6.2.1 Defining the domains of transformation matrix
      2. 6.2.2 Assigning complexity and risk ratings
    3. 6.3 Workload assessment summary
  10. Chapter 7. Transition approaches
    1. 7.1 Introduction and overview of transitional approaches
    2. 7.2 Application patterns
      1. 7.2.1 AP1: An application using a binary-compatible language
      2. 7.2.2 AP2: An application written in a standard language supported on System z
      3. 7.2.3 AP3: An application with a proprietary language and data store
      4. 7.2.4 Summary of application patterns
    3. 7.3 Transitional patterns
      1. 7.3.1 TP1: Buy a software package or recode the application from scratch
      2. 7.3.2 TP2: source code conversion
      3. 7.3.3 TP3: Port the existing application by recompiling on System z
      4. 7.3.4 TP4: Redeploy the existing application as it exists today
      5. 7.3.5 Summary of transitional patterns
      6. 7.3.6 Mapping application patterns to transitional patterns
      7. 7.3.7 Middleware provisioning
    4. 7.4 Switchover approaches
      1. 7.4.1 The big bang switchover approach
      2. 7.4.2 Shadowing with replication
      3. 7.4.3 Phased switchover
    5. 7.5 Options for application modernization
      1. 7.5.1 The case for application modernization
      2. 7.5.2 Aspects of application modernization
      3. 7.5.3 Modernization using a service oriented architecture
    6. 7.6 Summary
  11. Chapter 8. System z capacity planning, sizing, and TCO
    1. 8.1 Overview of sizing, capacity planning, and TCO considerations
    2. 8.2 The importance of sizing
    3. 8.3 Capacity planning importance
    4. 8.4 Data collection and analysis
      1. 8.4.1 Data collection
      2. 8.4.2 Workload characterization
      3. 8.4.3 Processor analysis
      4. 8.4.4 Memory analysis
      5. 8.4.5 Disk analysis (I/O)
      6. 8.4.6 Network analysis
    5. 8.5 Sizing methodologies
      1. 8.5.1 Sizing for consolidation or migration
      2. 8.5.2 Modeling and sizing tools
      3. 8.5.3 Sizing from scratch
      4. 8.5.4 Sizing High Availability and Disaster Recovery
    6. 8.6 Capacity planning methodologies
      1. 8.6.1 Guidelines
      2. 8.6.2 Linear projections
      3. 8.6.3 Analytic methods
      4. 8.6.4 Discrete methods
      5. 8.6.5 Real world benchmarks versus standard benchmarks
      6. 8.6.6 Processor capacity planning
      7. 8.6.7 Memory capacity planning
      8. 8.6.8 I/O capacity planning
      9. 8.6.9 Tools of capacity planning
    7. 8.7 TCO analysis
    8. 8.8 Post-sizing review
  12. Related publications
    1. IBM Redbooks
    2. Other publications
    3. Online resources
    4. How to get Redbooks
    5. Help from IBM
  13. Back cover