Redirector Test

File serving very often is a much underestimated part of server-based computing environments. Improperly configured file serving components can wreak havoc on a server farm’s performance.

File serving in server-based computing environments is used at different times. For instance, every time a user logs on or off, profile data may be copied back and forth between the file server and terminal server. Another example involves multiple applications accessing configurations stored in files from a remote file server. Folder redirection, if used, is another form of file retrievals from file servers.

File serving problems can have a detrimental impact on the performance of server-based computing environments. Often, these problems may manifest in many ways. For example, users may see very slow access to their home directory, or folders. Even with a small profile, logging on and off could take a long time. Random application crashes can also happen, especially for applications that rely on file servers to store their configuration files remotely. Such file serving problems are often the most difficult to diagnose.

The Redirector component of the Microsoft Windows operating system handles file serving at the client end, and the Redirector test monitors this component’s activity, and tracks the status of file serving as seen by a file server’s client.

Target of the test : A 2X Terminal Server

Agent deploying the test : An internal agent

Outputs of the test : One set of results for the 2X Terminal server being monitored

Configurable parameters for the test
Parameter Description

Test period

How often should the test be executed

Host

The host for which the test is to be configured

Port

Refers to the port used by the Terminal server

Measurements made by the test
Measurement Description Measurement Unit Interpretation

Data received

This metric shows the rate of data that were received by the local server from the network. This includes all the application data as well as network protocol information.

MB/Sec

 

Data sent

This metric represents the rate at which data is leaving the Redirector to the network. This includes all the application data as well as network protocol information.

 

MB/sec

 

Current commands

This metric indicates the number of requests to the Redirector that are currently queued for service.

Number

The Current Commands measure indicates the number of pending commands from the local computer to all destination servers. This means that if one of the destination servers does not respond in a timely manner, the number of current commands on the local computer may increase.

If the local computer is serving many sessions, a high number of current commands does not necessarily indicate a problem or a bottleneck. However, if the Current Commands measure shows a high number and the local computer is idle, this may indicate a network-related problem or a redirector bottleneck on the local computer. For example, there may be a network-related problem or a local bottleneck if the computer is idle overnight but the counter shows a high number during that period.

Network errors

This metric denotes the rate at which serious unexpected errors are occurring during file system access from a remote server.

Errors/sec

Such errors generally indicate that the Redirector and one or more Servers are having serious communication difficulties. For example an SMB (Server Manager Block) protocol error is a Network Error. An entry is written to the System Event Log and provides details.

Reads denied

This metric denotes the rate at which the server is unable to accommodate requests for raw read operations.

Reads/sec

When a read is much larger than the server's negotiated buffer size, the Redirector requests a Raw Read which, if granted, would permit the transfer of the data without lots of protocol overhead on each packet.  To accomplish this, the server must lock out other requests, so the request is denied if the server is really busy.

Hung server sessions

This metric shows the number of active sessions that are timed out and unable to proceed due to a lack of response from the remote file server.

 

Number

 

Writes denied

This metric denotes the rate at which the server is unable to accommodate requests for raw write operations

Writes/sec

When a write is much larger than the server's negotiated buffer size, the Redirector requests a Raw Write which, if granted, would permit the transfer of the data without lots of protocol overhead on each packet.  To accomplish this, the server must lock out other requests, so the request is denied if the server is really busy.