Applies To
Express Software Manager version 4.x through 5.x

Summary
This technical note lists the Express Software Manager (ESM) 4.x through 5.x system requirements, describes the expected administrative and network impact of running ESM, and provides suggestions for minimizing the impact on your network.

System Requirements
Express Metrix recommends the following minimum system requirements for running Express Software Manager:

System Administrator Machine (to run Express Console):

• Windows 2000, Windows NT version 4.0, Windows 98, or Windows 95, Microsoft Terminal Server with Multi-host MetaFrame

• Microsoft Networking, Novell NetWare, or NFS network connection

• Minimum hard disk space: 85 MB (an additional 35 MB if you install Express Services); 25 MB during installation

• Minimum monitor resolution: 800 x 600 (no VGA support)

• 18 MB initial hard disk space per library. Growth varies, but an additional 600K per client (metering or inventory) is often required.

• Microsoft Networking, Novell NetWare, or NFS network connection

• On NT Servers that host application libraries, disable Oplock. For more information, see Technical Note 1316.

• Windows 2000, Windows NT version 3.51 or 4.0, Windows 98, Windows 95, or Windows 3.1x, WinFrame 1.7, Microsoft Terminal Server. Express Inventory client can also run on DOS 4.0.

• Minimum hard disk space (for 32-bit Windows Client): 800K, 600K Windows Memory (pageable memory)

  Minimum hard disk space (for 16-bit Windows Client): 900K, 400K Windows Memory (pageable memory). Note: 16-bit Client uses no DOS memory.

• Microsoft Networking, Novell NetWare, or NFS network connection

• Minimum monitor resolution: 640 x 480 (supports VGA)

The Express client generates network traffic during these activities:

• Installation

• Metering applications

• Inventorying workstations

Metering Applications
A typical workstation that is metering to a library but not auto-adding applications or tracking crash detection will produce about 4 MB of network traffic over an eight-hour period

The Express metering client generates network traffic when

• a user logs on to a metering workstation

• a user logs off from a workstation

• an application is launched

• an application is closed

• the Applib.lib file has been modified by an administrator

• Crash Detection is enabled and an application is checked (the heartbeat)

• Applib.ini

• A00004s7.use

• Express.log

• Applib.key

• Applib.mch

• Applib.lgp

• Applib.lib

A user logging on for the first time after the client is installed to the workstation will also cause an increase in network traffic. When the client is not previously installed, the traffic will increase to a maximum of 850K. Once the Express client is installed on the workstation and Exinst.exe is in the login script, the client generates only about 150K of traffic when run.

Logging Off
When a user shuts down the machine or logs off from a workstation, some network traffic will occur. Depending on the number of applications in use when the shutdown command is received, this traffic can vary greatly. The logoff procedure includes writing to the operation's system log file and the A00004s7.use file. Depending upon the file size, this network traffic can vary from 50K to 100K.

Launching an Application
The amount of network traffic that is required to meter an application varies, depending on the following factors:

• Whether Maintain current usage is enabled for an application

• Whether the application is concurrently licensed

• How many users are currently using the application if Maintain current usage is enabled

• Whether the application was auto-added

Two following files are then created in the library, the .use file for the application, which is 500 to 900 bytes, and the .log file for the application, which is 5 to 10K.

Note: When the Auto-Added feature is enabled, a new application requires approximately 325 packets to be launched. When it is disabled, only 16 packets are required to launch a new application.

Effects of the Licensing and Current Usage Settings when launching an application
The following chart shows the network traffic generated in different scenarios when an application is launched.

Licensing	Maintain Current Usage	Number of packets	Traffic per user
Concurrent	Enabled	24	4K
Non-Concurrent	Enabled	28	4K
Non-Concurrent	Disabled	10	1.2K

Note: When a current usage application is launched, it must read the .use file for the application, which results in additional packets.

Closing an Application
The amount of network traffic required to close an application depends on the following factors:

• Whether the application was auto-added

• Whether Maintain current usage is enabled for an application

• Whether the application is concurrently licensed

• How many users are currently using the application if Maintain current usage is on

Effects of the Licensing and Current Usage Settings when closing an application
The following chart shows the network traffic generated by applications with different licensing and current usage settings.

Licensing	Maintain Current Usage	Number of packets	Traffic per user
Concurrent	Enabled	22	6K
Non-Concurrent	Enabled	24	8K
Non-Concurrent	Disabled	12	5.5K

Modifying the Applib.lib File
When a system administrator modifies the Applib.lib file by configuring auto-added files or by adding, removing or modifying applications or suites, the Applib.lib file is changed. Once the Applib.lib file has been modified, at the next launch, the metering client will automatically read the new Applib.lib file. The file size may range from 50K to a few megabytes.

Checking an Application (with Crash Detection Enabled)
Crash detection opens the A*.use file for every running application (other than the operating system). This process of checking each application is called the heartbeat. Enabling crash detection results in approximately 12 packets per application plus 20 frames of additional overhead per heartbeat. One user running one application will generate approximately 3K of network traffic per heartbeat.

Inventorying Workstations
The inventory client's network usage varies depending on the inventory settings in Express Console and the number of files on the workstation. Increasing the number of directories, time limit, number of files to scan, or percentage of disk will increase the traffic generated by the initial high impact inventory scan.

Inventorying a typical workstation with 250 folders and 2500 files yields the following results:

• A 30-second high impact scan yields about 520K of data transferred across the network.

• A 100-directory high-impact scan lasts about two and one-half minutes and produces approximately 80 to 100K of network traffic.

• A 500-file high-impact scan lasts about one and one-half minutes, and produce between 25 and 30K of network traffic.

• A low-impact scan of one machine takes about 30 minutes and produces about 5 MB of network traffic, or 165K per minute.

• Routinely configure and/or remove files from the Auto-Added folder.

• Routinely remove unnecessary applications from the library.

• Remove Exinst.exe from the login script.

• Modify the Applib.lib file at a time when few users are modifying applications, or copy the library locally, make the appropriate changes, and copy it back.

• Limit the size of each library to a maximum of 800 inventoried computers.

• Run inventory less frequently.

• In a large local area network or a network with limited bandwidth, limit the number of computers scanned with login scripts to 50 per day per library.

• Use the Library properties Inventory tab entries to limit inventory activity or optional command line switches to specify a high-impact scan to limit the scan time for each computer. See the online help for details. (Search for Exinv.exe|Optional installation switches.)

• Remove the client from the login script after all computers have been scanned. This will remove a very small amount of network traffic that is generated when the client checks the Wrqexp.id file to see if 30 days have elapsed since the last scan.

• Disable the auto-add feature.

• Disable crash detection or increase the time intervals.

• If metering, increase the Check application rate in the Metering tab in the Console.

• Monitor file access at the file server for unanticipated locking or caching failures.

Related Technical Notes

1298	Understanding the Inventory Process in Express Software Manager 4.x through 5.x
1316	Express Meter and Windows NT Server File Locking
1569	Network Impact of Express Software Manager 6.0
9991	Express Software Manager Technical Notes (5.x or lower)