Chapter 3 The License Finder

This chapter explains the use of the License Finder and includes the following topics:

3.1 The Purpose of the License Finder

The license finder provides license file path information to FLEXlm clients so that you do not have to configure LM_LICENSE_FILE environment variables for all your users. The license finder provides a single license file path to all clients.

The license finder is available in FLEXlm v4.0 and later.

Only applications linked with FLEXlm v4.0 (or later) will be able to use the license finder.

v5 + FLEXlm applications require the client to have FLEXLM_USE_FINDER environment variable set to enable the license finder. This is because the application uses gethostbyname() to find the finder, and this is a performance problem at some sites.

A FLEXlm application determines the name of the license file using the following algorithm:

Looks for LM_LICENSE_FILE; if set, uses this path.
Looks for the `license finder' if step (1) fails.

Uses port `FLEXLM' from the services map; if not present it uses port 744 (the `official' FLEXlm port)
attempts to connect to this port on flexlm_license_finder, flexlm_license_finder2, flexlm_license_finder3 in order. Connect timeout is fixed at 2 seconds. This is done with TCP/IP. No broadcasts are involved. (For debugging, the connect timeout can be modified by setting FLEXLM_FINDER_TIMEOUT to an integer). If the lookup of flexlm_license_finder fails, this step terminates.
If it can connect to any license finder, it gets the license file path from the finder.

Uses the default license file path if (1) and (2) fail.

3.2 Starting the License Finder

To start the license finder, execute the following command on the node flexlm_license_finder:

lmgrd -f finder_file

finder_file: license finder file

lmgrd, when it is operating as a license finder (-ffinder_file option), will ONLY process license finder request messages, and sends the license file path back to the client. This lmgrd will NOT start any vendor daemons or process any other client request. This functionality is delivered in lmgrd so that you do not need a separate executable.

On Unix, since it is prudent to avoid running processes as root that do not require root permissions, it is strongly recommended that this process be run as a non-privileged user.

3.3 Finder File Format

The `finder file' format is:

	DATA lfpath license_file_path

for example:

	DATA lfpath /usr/local/flexlm/licenses/license.dat:1234@host2

or:

	DATA lfpath C:\flexlm\license.dat:1234@host2

The license finder is not available on VMS or Netware systems.

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