Windows System Resource Manager Frequently Asked Questions

WSRM allows you to manage CPU and memory utilization on a per process basis. This means that an administrator can run multiple applications on a server with greater safety. WSRM prevents applications from consuming more than their allocated CPU and memory limits, thereby preventing one application from starving other applications of CPU and memory. As a result, you will have a more consistent and predictable user experience.

WSRM policies can be applied according to a time/date schedule. This allows administrators to free up CPU and memory for maintenance applications during non-peak hours, and for mission critical applications during peak hours.

The WSRM accounting feature allows administrators to generate, store, view, and export resource utilization reports for systems management, and service level agreement (SLA) tracking and billing purposes.

Windows System Resource Manager is not intended to handle other aspects of data center management such as:

Administrators need WSRM to address several scenarios when running multiple applications on a single server. Some of these scenarios include:

Yes, using policy profiling.

When consolidating multiple applications on a single server, it is critical to allocate each application access to the system resources that are required. This regulation reduces the ability of applications to interfere with each other. This resource allocation allows multiple applications to be safely consolidated onto fewer larger servers, thus reducing operating costs.

Today, administrators typically operate their servers at between 50 percent and 85 percent utilization. This ensures that there is spare capacity should applications require it. However, this also means that money has been spent on a system that is not fully utilized. WSRM enables administrators to consolidate multiple applications and allocate their system resources. Applications can operate within a defined resource policy, which lets servers provide higher levels of utilization and a consistent user experience.

Service level agreements (SLAs) are usually described using business metrics such as response time, number of users supported, and availability levels. Original equipment manufacturers (OEMs), vendors, and enterprise IT groups are looking for tools to help them prove they are meeting their SLAs. The reporting features of WSRM provide information on memory usage and CPU time to support SLA metrics.

WSRM uses soft caps. It will enforce the caps if the system becomes resource constrained. However, a greedy application may exceed its target and spike up, if other processes are using less than their allocation. WSRM re-allocates unused resources each second based on application demand.

This behavior is normal. Dips occur momentarily when the system uses the CPU to perform a policy switch. Every process uses the same set of CPUs and so affects the percentage of CPU time available to the processes that WSRM is monitoring. WSRM does not monitor wsrm.exe and certain other operating system processes, all of which receive as much CPU as they need complete tasks—including policy changing.

No. WSRM manages individual machines and is not cluster aware, so cluster members are managed separately.

Yes, the Command Line Interface (CLI) can invoke the WSRM Import/Export functions. It is probably simplest to use the same policy on each cluster node. However, this is not required and making them different might be used to address some failover scenarios.

Windows Server 2003 includes new support and optimizations based on NUMA architectures. WSRM does not attempt to further optimize applications' use of NUMA systems.

Since Terminal Server sessions correspond to processes spawned with the user's credentials, they can be managed by adding a user account name or security group name to the matching rule that matches an allocation to a process. Thus, an administrator has considerable flexibility in managing Terminal Services users by account and/or application either individually or by security group. This provides a consistent experience to users while also preventing some users from monopolizing resources at the expense of other users.

If performance is very important to you, you should not control SQL processor affinity using WSRM, this is better done directly by SQL Server via its administrative interface. WSRM can manage SQL Server, even if it is using affinity.

Process Control does not exist in Windows Server 2003. However if you upgrade from Windows 2000 Datacenter Server to Windows Server 2003 Datacenter Edition, Process Control will be left in place.

No. In addition, WSRM cannot manage processes that run in job objects, such as in the case of multiple resource managers or a self-managed application. Instead, WSRM uses published kernel APIs. CPU management is based on modifying process priority dynamically. Working set management uses kernel functions for setting working set limits. By monitoring and taking direct action, the WSRM service enforces committed memory limit.

Aurema's ARMTech is available for the Windows 2000 server family and Window Server 2003 products. Microsoft will continue to bundle ARMTech with Windows 2000 Datacenter Server; however, it will not be included with Windows Server 2003, which instead includes WSRM with the Enterprise and Datacenter Editions. Aurema will continue to improve their product giving our customers a range of choice in their resource management tools.

WSRM cannot properly manage a machine if any application (such as an OEM tool) is modifying the parameters that WSRM uses for management. These parameters include: thread or process priority, working set size and processor affinity. Note, placing a process into a Job Object has the effect of modifying these parameters. So any application that modifies priorities, working set size or uses job objects is very likely to interfere with WSRM's ability to manage.

No. Only a single manager at a time can be effective.

The administrator creates Process Matching Criteria that distinguish between multiple instances of the same process by matching modifiers on the command line specific to each running instance.

WSRM is included in the Enterprise and Datacenter Editions of Windows Server 2003. It is not included in the Windows Server 2003 Evaluation Kit, but can be downloaded separately.

No. Customers wishing to use WSRM will have to upgrade to either Windows Server 2003, Enterprise Edition, or Windows Server 2003, Datacenter Edition.

No.