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
Monitoring resource type and agent configuration
By default, VCS monitors each resource every 60 seconds. You can change this by modifying the MonitorInterval attribute for the resource type. You may consider reducing monitor frequency for non-critical or resources with expensive monitor operations. Note that reducing monitor frequency also means that VCS may take longer to detect a resource fault.
By default, VCS also monitors offline resources. This ensures that if someone brings the resource online outside of VCS control, VCS detects it and flags a concurrency violation for failover groups. To reduce the monitoring frequency of offline resources, modify the OfflineMonitorInterval attribute for the resource type.
The VCS agent framework uses multithreading to allow multiple resource operations to run in parallel for the same type of resources. For example, a single Mount agent handles all mount resources. The number of agent threads for most resource types is 10 by default. To change the default, modify the NumThreads attribute for the resource type. The maximum value of the NumThreads attribute is 30.
Continuing with this example, the Mount agent schedules the monitor function for all mount resources, based on the MonitorInterval or OfflineMonitorInterval attributes. If the number of mount resources is more than NumThreads, the monitor operation for some mount resources may be required to wait to execute the monitor function until the thread becomes free.
Additional considerations for modifying the NumThreads attribute include:
If you have only one or two resources of a given type, you can set NumThreads to a lower value.
If you have many resources of a given type, evaluate the time it takes for the monitor function to execute and the available CPU power for monitoring. For example, if you have 50 mount points, you may want to increase NumThreads to get the ideal performance for the Mount agent without affecting overall system performance.
You can also adjust how often VCS monitors various functions by modifying their associated attributes. The attributes MonitorTimeout, OnlineTimeOut, and OfflineTimeout indicate the maximum time (in seconds) within which the monitor, online, and offline functions must complete or else be terminated. The default for the MonitorTimeout attribute is 60 seconds. The defaults for the OnlineTimeout and OfflineTimeout attributes is 300 seconds. For best results, Arctera recommends measuring the time it takes to bring a resource online, take it offline, and monitor before modifying the defaults. Issue an online or offline command to measure the time it takes for each action. To measure how long it takes to monitor a resource, fault the resource and issue a probe, or bring the resource online outside of VCS control and issue a probe.
Agents typically run with normal priority. When you develop agents, consider the following:
If you write a custom agent, write the monitor function using C or C++. If you write a script-based monitor, VCS must invoke a new process each time with the monitor. This can be costly if you have many resources of that type.
If monitoring the resources is proving costly, you can divide it into cursory, or shallow monitoring, and the more extensive deep (or in-depth) monitoring. Whether to use shallow or deep monitoring depends on your configuration requirements.
As an additional consideration for agents, properly configure the attribute SystemList for your service group. For example, if you know that a service group can go online on SystemA and SystemB only, do not include other systems in the SystemList. This saves additional agent processes and monitoring overhead.