InfoScale™ 9.0 Cluster Server Administrator's Guide - Windows
- 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
- Agent classifications
- About cluster control, communications, and membership
- About security services
- About cluster topologies
- VCS configuration concepts
- Introducing Cluster Server
- Section II. Administration - Putting VCS to work
- About the VCS user privilege model
- Getting started with VCS
- Administering the cluster from the command line
- About administering VCS from the command line
- Stopping the VCS engine and related processes
- 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
- About administering resource types
- About administering clusters
- Configuring resources and applications in VCS
- About configuring resources and applications
- About Virtual Business Services
- About Intelligent Resource Monitoring (IMF)
- About fast failover
- How VCS monitors storage components
- About storage configuration
- About configuring network resources
- About configuring file shares
- About configuring IIS sites
- About configuring services
- Before you configure a service using the GenericService agent
- About configuring processes
- About configuring Microsoft Message Queuing (MSMQ)
- About configuring the infrastructure and support agents
- About configuring applications using the Application Configuration Wizard
- Adding resources to a service group
- About application monitoring on single-node clusters
- Configuring the service group in a non-shared storage environment
- About the VCS Application Manager utility
- About testing resource failover using virtual fire drills
- Modifying the cluster configuration
- Section III. Administration - Beyond the basics
- Controlling VCS behavior
- VCS behavior on resource faults
- About controlling VCS behavior at the service group level
- Customized behavior diagrams
- VCS behavior for resources that support the intentional offline functionality
- About controlling VCS behavior at the resource level
- Service group workload management
- Sample configurations depicting workload management
- The role of service group dependencies
- VCS event notification
- VCS event triggers
- List of event triggers
- Controlling VCS behavior
- Section IV. 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 replication resources in VCS
- 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 Cluster Manager (Java console)
- 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
- Connecting clusters–Creating global clusters
- Section V. Troubleshooting and performance
- VCS performance considerations
- How cluster components affect performance
- How cluster operations affect performance
- VCS performance consideration when a system panics
- VCS agent statistics
- Troubleshooting and recovery for VCS
- VCS message logging
- Handling network failure
- Troubleshooting VCS startup
- Troubleshooting service groups
- Troubleshooting and recovery for global clusters
- VCS utilities
- VCS performance considerations
- Section VI. Appendixes
- Appendix A. VCS user privileges—administration matrices
- Appendix B. Cluster and system states
- Appendix C. VCS attributes
- Appendix D. Configuring LLT over UDP
- Appendix E. Handling concurrency violation in any-to-any configurations
- Appendix F. Accessibility and VCS
- Appendix G. Executive Order logging
About Intelligent Resource Monitoring (IMF)
VCS traditionally uses a poll-based mechanism to detect the state of the configured applications and the underlying storage and network components. The agents retrieve the respective resource status during the monitor function. The monitor function is periodic and the frequency is defined by the resource type level attributes, MonitorInterval and OfflineMonitorInterval.
Intelligent Monitoring Framework (IMF) provides an alternative method for VCS to determine the resource status. IMF employs an event-based monitoring framework that is implemented using custom as well as native operating system-based notification mechanisms.
In poll-based monitoring, the resource state change detection is dependent on the monitor interval. Any state change that occurs immediately after a monitor cycle has completed is detected only in the next monitor cycle. This causes delays in fault detection. If the monitor interval attributes are set lower values, then in configurations with a large number of resources, poll-based monitoring may get CPU-intensive.
IMF uses an event-driven design that is asynchronous and provides instantaneous resource state change notifications. A resource state change event is quickly detected by VCS agents and then communicated to the VCS engine for further action. This improves the fault detection capability significantly allowing VCS to take corrective actions faster and that results in reduced service group failover times.
Note:
The actual intelligent monitoring for a VCS resource starts only after two consecutive traditional monitor cycles have run and have returned the same state for that resource. So it takes some time before you see positive performance effect after enabling IMF.
The benefits of intelligent monitoring over poll-based monitoring are as follows:
Instantaneous notification
Faster notification of resource state changes result in improved service group failover times.
Reduction in system resource utilization
Reduced CPU utilization by VCS agent processes when number of resources being monitored is high. This provides significant performance benefits in terms of system resource utilization.
Ability to monitor large number of resources
With reduced CPU consumption, IMF enables VCS to effectively monitor a large number of resources.