How FLEXlm-based license files work

Topic:

This TechTip discusses the structure and function of FLEXlm-based license files.Discussion:
A license file contains structural elements that control which products may run, how many sessions of the product may run, and on which machine the license manager runs. The FEATURE or INCREMENT lines of the license file determine which products are available. In addition, the number of license units (or tokens) of the FEATURE or INCREMENT lines control the number of copies of the product that may run concurrently. The SERVER lines define on which machines the license manager software runs.

License Units

Different types of computers require different numbers of license units to run IDL:

• Workstation-class machines running a UNIX-based OS such as Solaris, HP-UX, Tru64, or AIX require 10 license units per copy of IDL.
• Desktop-class machines running Windows, Linux or MacOS X require 6 license units per copy of IDL.

For example, in order to run IDL on a Sun Solaris workstation, IDL checks out 10 license units from the license server. To run IDL on a computer running Linux, IDL checks out 6 license units. On a mixed network consisting of both workstations and desktop-class machines, the number of copies of IDL available at any given time depends on which machines have checked out licenses.

An example IDL license file

The following example license file is built for the license server "hal" which has an LMHostid of 1497946. Multiple licenses are included in this license file: one unlimited node-locked license (1234-1), one 6-count UNIX node-locked license (1234-2) and a 4-count UNIX floating license (1234-3). For both node-locked licenses 1234-1 and 1234-2, the LMHostid is appended to the FEATURE or INCREMENT line after the end of the VENDOR_STRING. The second INCREMENT line provides four floating licenses (1234-3). The FEATURESET line at the bottom of the license contains a master checksum to tie the various FEATURE and INCREMENT lines together.

SERVER hal 1497946 1700
DAEMON idl_lmgrd /usr/local/rsi/idl_6.1/bin
FEATURE idl idl_lmgrd 6.100 1-jan-00 0 DB2CE0E19251E66D16FA \
     VENDOR_STRING="1234-1Acme Datawack Corp - hal" HOSTID=1497946 \
     ck=69
INCREMENT idl idl_lmgrd 6.100 1-jan-00 60 2BBC1021D4C72A51501F \
     VENDOR_STRING="1234-2Acme Datawack Corp - 1 tom" \
     HOSTID=5720ff5f ck=215
INCREMENT idl idl_lmgrd 6.100 1-jan-00 40 6B0CC081E93439AF61C2 \
     VENDOR_STRING="1234-3Acme Datawack Corp - 4 FL" ck=65
FEATURESET idl_lmgrd 8F51913A3B9BABCA

Please Note: The INCREMENT line for the 6-count node-locked license (the first INCREMENT line) shows 60 license units. Each counted IDL UNIX license requires 10 license units on the FEATURE or INCREMENT line. Similarly, the INCREMENT line for the 4-count floating license shows 40 UNIX license units.

The Individual Lines of the License File
The lines in a license file have the following meanings:

SERVER
There is one SERVER line for each license server node on your network. This line is not usually present in personal use, Windows node-locked or MU licenses. The fields contained in this line are:

nodename
The string that the UNIX command hostname returns for the license server.

id
The string that the lmhostid command returns for the license server. The LMHostID is derived from the MAC (Medium Access Control) address of the server's primary ethernet adapter.

port_number
The license manager daemon binds to TCP port 1700 by default. If the default selection of 1700 conflicts with another application running on the server, the port number may be changed to a different value. When the license manager daemons runs from a non-root account on a UNIX system, the specified port number must be greater than 1024.

DAEMON
There is only one DAEMON line related to Research Systems software in a license file. This line is not usually present in personal use, Windows node-locked, or MU licenses. The fields contained in this line are:

daemon_name
The name of the daemon executable (idl_lmgrd or idl_lmgrd.exe, depending on the server platform) that serves IDL licenses.

path
The path to the directory containing the daemon. The daemon is located in the bin subdirectory of the IDL distribution on UNIX systems. On Windows systems, idl_lmgrd.exe is located in the bin.x86 directory.

FEATURE
There is one FEATURE line per node-locked host or per floating license. Floating license FEATURE lines are always listed after any node-locked FEATURE lines. The FEATURE line fields are:

name
The name of the licensed software package, such as idl or envi.

daemon
The name of the IDL license daemon; this value is always idl_lmgrd for RSI products.

version
The maximum allowed version of the licensed software package.

exp_date
The FEATURE expiration date. For permanent licenses, this value is always 1-jan-0000

#license_units
This value specifies the number of allowed license units. As described above, the number of license units is derived from the number of licenses times the platform-dependent scale factor (6 or 10). For example, if you have 3 floating licenses for a Sun system, this field is set to 30. If the value is set to 0, then the FEATURE is unlimited node-locked.

code
The encryption code for this license.

VENDOR_STRING
A single string containing the combined license number and site notice.

HOSTID
If present, the host ID of the machine to which this license is node-locked. This field is only used in node-locked FEATURE lines--if this field is empty, this license is for floating network licenses.

ck
A checksum number can be used to check the validity of the FEATURE or INCREMENT line.

INCREMENT
Some license files may use INCREMENT lines in addition to (or instead of) FEATURE lines. INCREMENT lines contain the same fields as FEATURE lines.

FEATURESET
The FEATURESET line contains a master checksum to tie all of the lines related to the daemon idl_lmgrd together. FEATURE or INCREMENT lines for non-RSI FLEXlm-based products are not affected by the use of the FEATURESET line for the idl_lmgrd daemon.

Altering the License File
A user may only alter the following four data items:

• SERVER hostname (but not LMhostID)


• SERVER port number


• DAEMON file path


• DAEMON port number

Please note: Altering any other field, adding or deleting FEATURE or INCREMENT lines will render your license file unusable.Solution:
[Edit this field in the IDL-based Tech Tip Editor, v60]