2.2.10 Performance Counter Path
The syntax of a counter path is:
\\Computer\PerfObject(ParentInstance/ObjectInstance#InstanceIndex)\Counter
The Computer element specifies the name or IP address of the computer from which to query performance data. The computer name is optional if the counter is located on the local computer.
The PerfObject element specifies the performance object to query. A performance object can be a physical component, such as processors, disks, and memory, or a system object, such as processes and threads. Each system object is related to a functional element within the computer and has a set of standard counters assigned to it. Each computer can have a different set of performance objects and counters installed on it because applications can install their own performance objects and counters.
The ParentInstance, ObjectInstance, and InstanceIndex are included in the path if multiple instances of the object can exist. For example, processes and threads are multiple instance objects because more than one process or thread can run at the same time. If an object can have more than one instance, the counter path needs to specify an object instance.
The format of the instance related elements depends on the object type. If the object has simple instances, then the format is only the instance name enclosed in parentheses. For example:
(Explorer) If the instance of this object also requires a parent instance name, the parent instance name needs to come before the object instance and be separated by a forward slash character. For example, threads belong to processes. If a thread object is queried, the process to which it belongs also needs to be specified, as shown in the following example:
(Explorer/0) If the object has multiple instances that have the same name string, they can be indexed sequentially by specifying the instance index prefixed by a pound sign. Instance indexes are 0-based. If you want to query the first instance, do not include #0—just specify the instance name. To specify the second instance, use #1; to specify the third instance, use #2; and so on. For example:
(Explorer/0#1) The Counter element specifies the performance counter to query for the given the performance object.
The Counter is specified by appending either a '>' or '<' sign along with a value.
The PLA protocol cannot be used to discover which performance counters are available either on the target remote or local machine; the PLA protocol can only be used to query for performance counter values on the target machine (please see section 2.2.13 for an example of how this is done). Clients that are interested in discovering which performance counters are available can either use the [MS-RRP] or [MS-PCQ] protocols. Once a client has determined the performance counters whose values it wishes to query for, the client can then use the PLA protocol to do so, specifying each performance counter using the syntax described in this section.