InfoScale™ 9.0 Cluster Server Administrator's Guide - Linux
- Section I. Clustering concepts and terminology
- Introducing Cluster Server
- About Cluster Server
- About cluster control guidelines
- About the physical components of VCS
- Logical components of VCS
- Types of service groups
- About resource monitoring
- Agent classifications
- About cluster control, communications, and membership
- About security services
- Components for administering VCS
- About cluster topologies
- VCS configuration concepts
- Introducing Cluster Server
- Section II. Administration - Putting VCS to work
- About the VCS user privilege model
- Administering the cluster from the command line
- About administering VCS from the command line
- About installing a VCS license
- Administering LLT
- Starting VCS
- Stopping the VCS engine and related processes
- Logging on to VCS
- About managing VCS configuration files
- About managing VCS users from the command line
- About querying VCS
- About administering service groups
- Modifying service group attributes
- About administering resources
- Enabling and disabling IMF for agents by using script
- Linking and unlinking resources
- About administering resource types
- About administering clusters
- Configuring applications and resources in VCS
- VCS bundled agents for UNIX
- About application monitoring on single-node clusters
- Configuring NFS service groups
- About NFS
- Configuring NFS service groups
- Sample configurations
- About configuring the RemoteGroup agent
- About configuring Samba service groups
- About testing resource failover by using HA fire drills
- Section III. VCS communication and operations
- About communications, membership, and data protection in the cluster
- About cluster communications
- About cluster membership
- About membership arbitration
- About membership arbitration components
- About server-based I/O fencing
- About majority-based fencing
- About the CP server service group
- About secure communication between the VCS cluster and CP server
- About data protection
- Examples of VCS operation with I/O fencing
- About cluster membership and data protection without I/O fencing
- Examples of VCS operation without I/O fencing
- Administering I/O fencing
- About the vxfentsthdw utility
- Testing the coordinator disk group using the -c option of vxfentsthdw
- About the vxfenadm utility
- About the vxfenclearpre utility
- About the vxfenswap utility
- About administering the coordination point server
- About configuring a CP server to support IPv6 or dual stack
- About migrating between disk-based and server-based fencing configurations
- Migrating between fencing configurations using response files
- Controlling VCS behavior
- VCS behavior on resource faults
- About controlling VCS behavior at the service group level
- About AdaptiveHA
- Customized behavior diagrams
- About preventing concurrency violation
- VCS behavior for resources that support the intentional offline functionality
- VCS behavior when a service group is restarted
- About controlling VCS behavior at the resource level
- VCS behavior on loss of storage connectivity
- Service group workload management
- Sample configurations depicting workload management
- The role of service group dependencies
- About communications, membership, and data protection in the cluster
- Section IV. Administration - Beyond the basics
- VCS event notification
- VCS event triggers
- Using event triggers
- List of event triggers
- Virtual Business Services
- Section V. Cluster configurations for disaster recovery
- Connecting clusters–Creating global clusters
- VCS global clusters: The building blocks
- About global cluster management
- About serialization - The Authority attribute
- Prerequisites for global clusters
- Setting up a global cluster
- Configuring clusters for global cluster setup
- Configuring service groups for global cluster setup
- About IPv6 support with global clusters
- About cluster faults
- About setting up a disaster recovery fire drill
- Test scenario for a multi-tiered environment
- Administering global clusters from the command line
- About global querying in a global cluster setup
- Administering clusters in global cluster setup
- Setting up replicated data clusters
- Setting up campus clusters
- Connecting clusters–Creating global clusters
- Section VI. Troubleshooting and performance
- VCS performance considerations
- How cluster components affect performance
- How cluster operations affect performance
- VCS performance consideration when a system panics
- About scheduling class and priority configuration
- VCS agent statistics
- About VCS tunable parameters
- Troubleshooting and recovery for VCS
- VCS message logging
- Gathering VCS information for support analysis
- Troubleshooting the VCS engine
- Troubleshooting Low Latency Transport (LLT)
- Troubleshooting Group Membership Services/Atomic Broadcast (GAB)
- Troubleshooting VCS startup
- Troubleshooting issues with systemd unit service files
- Troubleshooting service groups
- Troubleshooting resources
- Troubleshooting sites
- Troubleshooting I/O fencing
- Fencing startup reports preexisting split-brain
- Troubleshooting CP server
- Troubleshooting server-based fencing on the VCS cluster nodes
- Issues during online migration of coordination points
- Troubleshooting notification
- Troubleshooting and recovery for global clusters
- Troubleshooting licensing
- Licensing error messages
- Troubleshooting secure configurations
- VCS message logging
- VCS performance considerations
- Section VII. Appendixes
About application monitoring on single-node clusters
Cluster Server (VCS) lets you configure HA for applications in single-node deployments, which do not involve any clustering of nodes. This feature is termed application monitoring on single-node clusters. The LLT, GAB, and fencing mechanisms are not involved, because there are no other nodes to communicate with or to monitor. In such a deployment, if a fault occurs with an application configured for HA, it is not failed over to any other node, but restarted on the same node. If an application is unable to come online or to recover after the predefined restart attempts, VCS uses the heartbeat mechanism to inform VMware of the application state.
VCS integrates with the underlying virtualization infrastructure to provide application HA. For example, VMware provides virtual machine (VM) monitoring capabilities through the vSphere Guest SDK. The SDK enables applications to heartbeat with VMware, and when a failure occurs, VMware takes the appropriate corrective action, like restarting or moving the VM.
Application monitoring on single-node clusters involves the following components:
The AppMonHB agent, which integrates with the application and with VMware. It monitors the application states, and if the application is unable to come online or to recover from a failure, it uses the heartbeat mechanism to inform VMware of the state. Additionally, if the VM is in an unhealthy state, AppMonHB cannot heartbeat with VMware, which indicates that corrective action is required. VMware may then restart the VM or move it, according to the virtualization configuration in your environment. AppMonHB is designed to wait for a predefined, customizable duration before taking any corrective action in case a fault occurs in any of the critical service groups. If the faulted service groups come online within this duration, no corrective action is taken.
For details, refer to the Cluster Server Bundled Agents Reference Guide - Linux.
The ConfigAppMonHB utility, which lets you configure the AppMonHB agent and the VCSAppMonRes resource. It also ensures that the feature is enabled on single-node deployments only. However, make sure that you do not enable the feature in a multi-node cluster; doing so may have unpredictable and undesirable effects.
See Configuring application monitoring on a single-node cluster.
See Verifying whether application monitoring is enabled on the single-node cluster.
See Unconfiguring application monitoring on a single-node cluster.
See About reviewing and troubleshooting the configuration and monitoring activities.