High Availability and Disaster Recovery (eBook)

Preface 6
Contents 8
1 Introduction 12
1.1 Audience 13
1.2 Roadmap of This Book 15
1.3 Real-World Examples 19
2 Elementary Concepts 24
2.1 Business Issues 25
2.2 System and Outage Categorization 28
2.3 High Availability – Handling Minor Outages 33
2.4 Disaster Recovery – Handling Major Outages 37
2.5 Quantifying Availability: 99.9. . .% and Reality 40
2.6 Service Level Agreements 42
2.7 Basic Approach: Robustness and Redundancy 45
2.8 Layered Solution with Multiple Precautions 49
2.9 Summary 50
3 Architecture 52
3.1 Objectives 56
3.2 Conceptual Model 59
3.3 System Model 62
4 System Design 66
4.1 Base Concepts 66
4.2 Solution Roadmap 89
4.3 System Solution Patterns 97
5 Hardware 110
5.1 Components and Computer Systems 115
5.2 Disk Storage 119
5.3 Virtualization of Resources 137
5.4 Vendor Selection and Purchasing Decisions 139
5.5 System Installation 143
5.6 System Maintenance and Operations 150
5.7 Making Our Own Statistics 153
6 Operating Systems 160
6.1 Failover Clusters 162
6.2 Load-Balancing Clusters 187
6.3 Cluster and Server Consolidation 194
7 Databases and Middleware 200
7.1 Middleware Categories 202
7.2 Database Servers 204
7.3 Web Servers 216
7.4 Application Servers 219
7.5 Messaging Servers 224
8 Applications 226
8.1 Integration in a Cluster on the Operating System Level 228
8.2 High Availability Through Middleware 234
8.3 High Availability From Scratch 236
8.4 Code Quality Is Important 238
8.5 Testing for High Availability 240
9 Infrastructure 244
9.1 Network 245
9.2 Infrastructure Services 278
9.3 Backup and Restore 294
9.4 Monitoring 295
10 Disaster Recovery 298
10.1 Concepts 300
10.2 Approach 302
10.3 Conceptual Design 303
10.4 Solutions 316
10.5 Disaster-Recovery Tests 329
10.6 Holistic View – What Is Needed Besides Technology? 333
10.7 A Prototypical Disaster-Recovery Project 335
10.8 Failover to Disaster-Recovery Site or Disaster- Recovery Systems 362
A Reliability Calculations and Statistics 370
A.1 Mathematical Basics 371
A.2 Mean Time Between Failures and Annual Failure Rate 373
A.3 Redundancy and Probability of Failures 374
A.4 Raid Configurations 376
A.5 Example Calculations 383
A.6 Reliability over Time – the Bathtub Curve 385
B Data Centers 388
B.1 Room Installation 389
B.2 Heat and Fire Control 392
B.3 Power Control 395
B.4 Computer Setup 397
C Service Support Processes 398
C.1 Incident Management 399
C.2 Problem Management 400
C.3 Configuration Management 402
C.4 Change Management 405
C.5 Release Management 406
C.6 Information Gathering and Reporting 408
References 410
Index 412