Manage Applications' Conflicts

Though you can run multiple applications on a single server, it may happen that one application may consume all available system resources, due to heavy user load or bugs. This problem makes IT teams use separate servers for different applications, leading to increased costs and system-manage- ment hassles.

With WSRM (Windows System Resource Manager), which comes with Windows Server 2003 Enterprise and Datacenter editions, you can run multiple applications on a single system in a manner that no single application can drain entire system resources. You can limit the amount of CPU and memory resources that individual applications can use. Any attempt by an application to use more resources than allocated will make WSRM terminate the application or create a log of it for administrative purposes. 

The system administrator needs to first calculate the applications' requirements that he intends to run on the server and then assign appropriate resources to these applications using the WSRM management console. Though we cannot calculate your applications' system requirements, we can tell you how to allocate resources to applications using
WSRM.

Creating resource-allocation policies

A resource-allocation policy defines the amount of CPU and memory that will be available to different applications. You can allocate resources to either individual or a group of applications. To create this policy, follow the steps below.

l On the left pane of the WSRM management console, right click on 'Resource Allocation Policy' and then click on 'New Resource Allocation Policy'.

l In the new window, type in a name for the new 'Resource Allocation Policy' and then click on Add.

l Select a process-matching criterion on the basis of which WSRM will club the processes and apply the 'Resource Allocation Policy' on that group of processes. Now you can either use the default 'Equal to all user' process-matching criterion or add a new one yourself.

Creating a process matching criteria

l In 'Criteria Name', type a descriptive name for the new process-matching criterion, then click on Add. 

l On the 'Files Or Command Lines' tab, you can specify a process manually by typing the file name. You can also choose the process from a list by selecting 'Registered Service', 'Running Process' or 'Application', and then clicking on Select. 

l If you selected either 'Registered Service' or 'Running Process', click on the process you want to match, and then click on Ok. If you selected 'Application', type the path to the location of the application's executable file or browse and select it.

A new process-matching criterion can also be specified by right clicking on 'Process-matching criterion' in the left pane of the WSRM management console.



Assigning CPU and memory to processes

l Once the process-matching criterion is in place, you have to set the processor-usage limit for the applications specified in this 'Resource Allocation Policy'. For this, select the percentage of processor usage allowed, which may vary from 0 to 99 percent. Hundred percent processor usage cannot be allocated as one percent is always reserved for default processes.

l Now, set the maximum memory allocation for these processes. For this, check the 'Use Maximum Committed Memory For Each Process' box under the Memory tab. Then specify the maximum committed memory limit per process in MB. You can also select the course of action to be taken in case the process tries to exceed the maximum allocated memory. There are two options for this: 'Close the Application' or 'Create a Log'.

l Go to the Advanced tab now, and specify the number of processors (on a multiple processor system) to be used by this group of processes. Check the 'Use Specified Processor' box and type in the number of processors you want to use.

l You can also sub-allocate processor resources. This can only be done if the management rule is set to Standard. You can choose from three management rules: Standard, Equal per user and Equal per process.

You can create a number of such resource-allocation policies. You just have to right click on the policy that you want to set as your management policy and then click on 'Set as management policy' in the resulting menu. 

Scheduling

WSRM policies can be applied according to time or date schedule. So, for example, you can schedule to run those non-critical tasks that consume a lot of resources at a time when critical applications are not running. Here's how to fix a schedule of different resource-allocation policies to be active at different times.



l Right click on the Schedules icon (in the left pane of the WSRM interface) and select 'New schedule' in the resulting menu. A new window will open on your screen.

l Give a name to the new schedule. Now right click on the left side of your screen where the time slots are given (the time gap between the time slots can be altered, varying from 60 minutes to 10 minutes) and click on 'Add Schedule Item'.

l Then, specify the policy name, its start time and end time.

You have to add events in the various time slots, repeating the process of right clicking in that particular time slot and then specifying the policy name, start time and end time.

Other features

This include its Resource Monitor, which gives a real-time graphical view of the system resources being used, such as the processor utilization and memory usage. WSRM also has an Accounting option that can be enabled or disabled by right clicking on the Accounting icon in the left pane of the WSRM interface. It gives a full account of the processes running and
their other details. 

Ankit Kawatra