Availability Clustering

Transcription

1 Pro Linux High Availability Clustering Sander van Vugt Apress"

2 Contents About the Author. xiii About the Technical Reviewers Acknowledgments Introduction xv xvii xix Chapter 1: High Availability Clustering and Its Architecture 1 Different Kinds of Clustering 1 High Performance Clusters 1 Load Balancing Clusters 2 High Availability Clusters 3 What to Expect from High Availability Clusters 3 History of High Availability Clustering in Linux 4 Heartbeat 2.0 and Red Hat Cluster Suite 4 Cluster Membership and Resource Management 4 The Components That Build a High Availability Cluster 4 Shared Storage 5 Different Networks 5 Bonded Network Devices 6 Multipathing 6 Fencing/STONITH Devices and Quorum 6 Summary 7 vii

3 Chapter 2: Configuring Storage 9 Why Most Clusters Need Shared Storage 9 NASor SAN? 10 NAS 10 SAN 10 iscsi or Fibre Channel?.11 Understanding iscsi 12 Configuring the LIO iscsi Target 12 Connecting to an iscsi SAN 16 Step 1: discovery Mode 17 Step 2: node Mode 18 Step 3: Managing the iscsi Connection 19 Disconnecting an iscsi Session 20 Setting Up Multipathing 20 /etc/multipath.conf 22 Specific Use Cases for Multipath 24 Summary 26 Chapter 3: Configuring the Membership Layer 27 Configuring the Network 27 Network Bonding Modes 28 Configuring the Bond Interface 28 Dealing with Multicast 29 corosync or cman? 30 Configuring corosync 30 Understanding corosyncconf Settings 33 Networks Without Multicast Support 33 Configuring cman 35 Summary 36 viii

4 Chapter 4: Understanding Pacemaker Architecture and Management 37 Pacemaker Related to Other Parts of the Cluster 37 Resource Agents 38 corosync/cman 38 The Storage Layer 38 Pacemaker Internal Components 38 Cluster Information Base 39 crmd 41 pengine 41 Irmd 41 stonithd/fenced 41 Cluster Management Tools 42 crm shell 42 Hawk 45 Other Tools 48 Conga: Luci and Ricci 49 Summary 49 Chapter 5: Configuring Essential Cluster Settings 51 Specifying Default Cluster Settings 51 no-quorum-policy 51 default-resource-stickiness 52 stonith-action 53 Setting Up STONITH 53 Different Solutions 54 Setting Up libvirt Hypervisor-Based STONITH 55 Setting Up Hardware-Based STONITH: The APC Master Power Switch 58 Configuring STONITH for Dell DRAC and Other Server Management Cards, Such As HP ILO 63 IPMI and Other Management Boards 66 Setting Up Shared Disk-Based STONITH 67 Using Fencing on Red Hat Clusters 68 Summary 69 ix

5 Chapter 6: Clustering Resources 71 What Makes Clustered Resources Different 71 Clustering an Apache File Server 71 Creating Resources 72 Grouping Resources 76 Working with Constraints 77 Constraint Types 77 Understanding Scores 78 Testing the Configuration 81 Understanding Resource Agent Scripts 81 Summary 85 Chapter 7: Clustering Storage 87 Using a Cluster File System 87 Configuring an 0CFS2 File System 88 Understanding Clone Resources 88 LVM2 in Cluster Environments 90 0CFS2 on Top of CLVM2 94 Using GFS2 with Pacemaker 95 Summary 95 Chapter 8: Performing Daily Cluster Management Tasks 97 Starting and Stopping Resources 97 Monitoring Resource State 98 Resource Migration 102 Using Resource Cleanup 103 Managing Nodes 104 Using Unmanaged Mode and Maintenance Mode for Maintenance 104 Understanding Log Files 105 X

6 Backup and Restore of the Cluster Configuration 107 Wipe Everything and Start All Over 108 Summary 108 Chapter 9: Creating an Open Source SAN 109 Creating an Open Source SAN with Pacemaker 109 Configuring RAID 1 over the Network with DRBD 109 Precautionary Measures 110 Creating the Configuration 110 Working with the DRBD 113 Troubleshooting the Disconnect State 113 Working with Dual Primary Mode 114 Integrating DRBD in Pacemaker Clusters 114 Testing 115 Adding an iscsi Target to the Open Source SAN 115 Creating an Open Source SAN with LVM 117 Setting Up the iscsi Target in the Cluster 117 Summary 120 Chapter 10: Use Case: Creating a Solution for Xen/KVM High Availability 121 Introduction: An Overview of Open Source Virtualization Solutions 121 Xen 121 KVM 122 Requirements for Setting Up an HA Solution for Virtual Machines 122 Example of a Virtual Machine HA Cluster 122 Creating a KVM HA Cluster 128 Creating the Base Cluster 129 Configure the SAN for Shared Storage 129 Installing a KVM Virtual Machine 130 Setting Up Cluster Resources for the KVM Virtual Machine 131 Summary 132 xi

7 Chapter 11: Use Case: Configuring a Load-Balanced Mail Front End with a Database Back End 133 Customer Situation 133 Database Back End 134 Mail Front End 136 One Big Cluster or Many Little Clusters? 138 Summary 139 Index 141 xii