Cluster Server 7.4.1 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
- 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
- Predicting VCS behavior using VCS Simulator
- 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. Veritas High Availability Configuration wizard
- Introducing the Veritas High Availability Configuration wizard
- Administering application monitoring from the Veritas High Availability view
- Administering application monitoring from the Veritas High Availability view
- Administering application monitoring from the Veritas High Availability view
- Section VI. 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
- 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 VII. 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
- Troubleshooting wizard-based configuration issues
- Troubleshooting issues with the Veritas High Availability view
- VCS message logging
- VCS performance considerations
- Section VIII. Appendixes
VCS agent statistics
You can configure VCS to track the time taken for monitoring resources.
You can use these statistics to configure the MonitorTimeout attribute.
You can also detect potential problems with resources and systems on which resources are online by analyzing the trends in the time taken by the resource's monitor cycle. Note that VCS keeps track of monitor cycle times for online resources only.
VCS calculates the time taken for a monitor cycle to complete and computes an average of monitor times after a specific number of monitor cycles and stores the average in a resource-level attribute.
VCS also tracks increasing trends in the monitor cycle times and sends notifications about sudden and gradual increases in monitor times.
VCS uses the following parameters to compute the average monitor time and to detect increasing trends in monitor cycle times:
Frequency: The number of monitor cycles after which the monitor time average is computed and sent to the VCS engine.
For example, if Frequency is set to 10, VCS computes the average monitor time after every 10 monitor cycles.
ExpectedValue: The expected monitor time (in milliseconds) for a resource.
VCS sends a notification if the actual monitor time exceeds the expected monitor time by the ValueThreshold. So, if you set this attribute to 5000 for a FileOnOff resource, and if ValueThreshold is set to 40%, VCS will send a notification only when the monitor cycle for the FileOnOff resource exceeds the expected time by over 40%, that is 7000 milliseconds.
ValueThreshold: The maximum permissible deviation (in percent) from the expected monitor time. When the time for a monitor cycle exceeds this limit, VCS sends a notification about the sudden increase or decrease in monitor time.
For example, a value of 100 means that VCS sends a notification if the actual monitor time deviates from the expected time by over 100%.
VCS sends these notifications conservatively. If 12 consecutive monitor cycles exceed the threshold limit, VCS sends a notification for the first spike, and then a collective notification for the next 10 consecutive spikes.
AvgThreshold: The threshold value (in percent) for increase in the average monitor cycle time for a resource.
VCS maintains a running average of the time taken by the monitor cycles of a resource. The first such computed running average is used as a benchmark average. If the current running average for a resource differs from the benchmark average by more than this threshold value, VCS regards this as a sign of gradual increase or decrease in monitor cycle times and sends a notification about it for the resource. Whenever such an event occurs, VCS resets the internally maintained benchmark average to this new average. VCS sends notifications regardless of whether the deviation is an increase or decrease in the monitor cycle time.
For example, a value of 25 means that if the actual average monitor time is 25% more than the benchmark monitor time average, VCS sends a notification.