Unicast Service Performance Counters

The following table provides a list and description of each of the NetShow Unicast service performance counters.

Performance counter Description

Active Almost-Live Streams Number of active almost-live streams currently being sent to NetShow Players.

Active Streams Number of active files, or streams, currently being sent to NetShow Players. Provides an overall indicator of system activity. Note that a client is still connected even if it has stopped playing a file; this is because the NetShow Unicast service maintains the bandwidth allocation to that client for 60 seconds after the client stops playing (this is called the Client Inactivity Time-out period). After the Client Inactivity Time-out period has elapsed, the server actively checks the client's status by periodically sending a message to each client. The server will keep a client connection open as long as the client responds to a message within three minutes (this is called the Client Terminal Time-out).

Active TCP Streams Number of active TCP streams currently being sent to NetShow Players.

Active UDP Streams Number of active UDP streams currently being sent to NetShow Players.

Aggregate Read Rate Sum, in bytes per second, of the read rates for all files being sent to NetShow Players. Indicates the speed at which the server is reading data from disk. The graph usually appears jagged because reads are faster than sends.

Aggregate Send Rate Sum, in bytes per second, of the send rates for all files being sent to NetShow Players. Indicates the speed at which the server is sending data to NetShow Players. The graph should appear relatively smooth; a jagged graph may indicate bandwidth contention.

Allocated Bandwidth Amount of bandwidth that the server allocates, based on the number of currently connected NetShow Players. Generally, clients connected to NetShow and not receiving streams are still allocated bandwidth. If a NetShow Player has allocated bandwidth but does not send a command during the Client Inactivity Time-out period, its bandwidth is de-allocated. Client Inactivity Time-out period = 60 seconds.

Connected Clients Number of client programs currently connected. Indicates all NetShow Players connected to the system. This includes clients streaming, clients in paused and connected states, and clients that the server has not yet detected as being disconnected. The latter may occur if a client has lost power or disconnected from the network and has not been able to notify the server of termination. After the Client Inactivity Time-out period has elapsed (60 seconds), the NetShow Unicast service actively checks the client's status by periodically sending a message to each client. Clients must reply to the message within three minutes in order to maintain their connection to the server (this is called the Client Terminal Time-out).

Connection Rate The rate at which clients are connecting to the server. This is used to gate the number of instantaneous connections being serviced by the server. The default is 10 connections per second. This counter is useful for correlating client connections with system resource utilization.

HTTP Streams Number of active HTTP streams currently being sent to NetShow Players.

Late Reads The number of late read completions per second. A late read is a disk read operation that takes significantly longer than expected to complete. Typically, this counter is non-zero only when the server is under a very heavy load. If this counter is often non-zero, it could indicate that the system is not properly configured (for example, you may need to use additional hard drives, or use a lower setting for the maximum number of clients), or that other applications are competing with NetShow for the use of the disk.

Scheduling Rate Rate at which requests are being made for tasks to be scheduled, in tasks per second. The only tasks that are currently scheduled are writes to the network. The scheduling rate is roughly proportional to the rate at which packets are being sent by the server (this rate does not represent a one-to-one correspondence).

Stream Errors The number of errors occurring per second. Stream errors represent the number of stream data packets discarded by the server. They are introduced by the server when it cannot keep up with the demand for data and must throw some packets away in order to avoid running behind schedule indefinitely. Stream errors show up most often after late reads occur. They are an indication that the system is not properly configured, or that other applications are competing for system resources (CPU, disk, RAM). Heavy network traffic can also contribute to stream errors.

Stream Terminations The rate at which streams are terminated due to errors. Stream terminations are an indication that the system is not properly configured, or that the file being streamed is corrupt. The server will unilaterally terminate a stream under certain circumstances. The most common occurrence of stream termination is when the server is running significantly behind schedule. If the server must throw away several packets in a row from a given stream in order to remain on schedule, it will terminate the stream. Streams can also be terminated if invalid data is encountered during file streaming.

Performance counter	Description
Active Almost-Live Streams	Number of active almost-live streams currently being sent to NetShow Players.
Active Streams	Number of active files, or streams, currently being sent to NetShow Players. Provides an overall indicator of system activity. Note that a client is still connected even if it has stopped playing a file; this is because the NetShow Unicast service maintains the bandwidth allocation to that client for 60 seconds after the client stops playing (this is called the Client Inactivity Time-out period). After the Client Inactivity Time-out period has elapsed, the server actively checks the client's status by periodically sending a message to each client. The server will keep a client connection open as long as the client responds to a message within three minutes (this is called the Client Terminal Time-out).
Active TCP Streams	Number of active TCP streams currently being sent to NetShow Players.
Active UDP Streams	Number of active UDP streams currently being sent to NetShow Players.
Aggregate Read Rate	Sum, in bytes per second, of the read rates for all files being sent to NetShow Players. Indicates the speed at which the server is reading data from disk. The graph usually appears jagged because reads are faster than sends.
Aggregate Send Rate	Sum, in bytes per second, of the send rates for all files being sent to NetShow Players. Indicates the speed at which the server is sending data to NetShow Players. The graph should appear relatively smooth; a jagged graph may indicate bandwidth contention.
Allocated Bandwidth	Amount of bandwidth that the server allocates, based on the number of currently connected NetShow Players. Generally, clients connected to NetShow and not receiving streams are still allocated bandwidth. If a NetShow Player has allocated bandwidth but does not send a command during the Client Inactivity Time-out period, its bandwidth is de-allocated. Client Inactivity Time-out period = 60 seconds.
Connected Clients	Number of client programs currently connected. Indicates all NetShow Players connected to the system. This includes clients streaming, clients in paused and connected states, and clients that the server has not yet detected as being disconnected. The latter may occur if a client has lost power or disconnected from the network and has not been able to notify the server of termination. After the Client Inactivity Time-out period has elapsed (60 seconds), the NetShow Unicast service actively checks the client's status by periodically sending a message to each client. Clients must reply to the message within three minutes in order to maintain their connection to the server (this is called the Client Terminal Time-out).
Connection Rate	The rate at which clients are connecting to the server. This is used to gate the number of instantaneous connections being serviced by the server. The default is 10 connections per second. This counter is useful for correlating client connections with system resource utilization.
HTTP Streams	Number of active HTTP streams currently being sent to NetShow Players.
Late Reads	The number of late read completions per second. A late read is a disk read operation that takes significantly longer than expected to complete. Typically, this counter is non-zero only when the server is under a very heavy load. If this counter is often non-zero, it could indicate that the system is not properly configured (for example, you may need to use additional hard drives, or use a lower setting for the maximum number of clients), or that other applications are competing with NetShow for the use of the disk.
Scheduling Rate	Rate at which requests are being made for tasks to be scheduled, in tasks per second. The only tasks that are currently scheduled are writes to the network. The scheduling rate is roughly proportional to the rate at which packets are being sent by the server (this rate does not represent a one-to-one correspondence).
Stream Errors	The number of errors occurring per second. Stream errors represent the number of stream data packets discarded by the server. They are introduced by the server when it cannot keep up with the demand for data and must throw some packets away in order to avoid running behind schedule indefinitely. Stream errors show up most often after late reads occur. They are an indication that the system is not properly configured, or that other applications are competing for system resources (CPU, disk, RAM). Heavy network traffic can also contribute to stream errors.
Stream Terminations	The rate at which streams are terminated due to errors. Stream terminations are an indication that the system is not properly configured, or that the file being streamed is corrupt. The server will unilaterally terminate a stream under certain circumstances. The most common occurrence of stream termination is when the server is running significantly behind schedule. If the server must throw away several packets in a row from a given stream in order to remain on schedule, it will terminate the stream. Streams can also be terminated if invalid data is encountered during file streaming.