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Optimising license checkouts from a floating license server

Applies to: ARM Developer Suite (ADS), RealView Development Suite (RVDS), Tool Licensing (License Management)


When using a license server (or servers), each time a client machine invokes one of the ARM tool executables, a license checkout request will be sent across the network to the license server to obtain a license. There are a number of ways of configuring a client machine to check out a floating license from a license server and it is worth ensuring that your system is configured in such a way that the time taken for these checkout requests is minimised.

  • Use the ARMLMD_LICENSE_FILE environment variable to point to your license server(s). This environment variable is examined first by the tools, so it is preferable to use this rather than LM_LICENSE_FILE (the generic FLEXnet/FLEXlm environment variable).

  • Set ARMLMD_LICENSE_FILE to 'port@servername' rather than pointing it to a local copy of the license file. This removes the delay incurred by the tools having to process the local copy of the license file to find out the name of the license server. Note that this variable can also be used to specify multiple locations (using a list separated by semi-colons on Windows, or colons on Unix) and each location will be checked in turn until a valid license is found.

  • Check for network problems. If everything is working as it should be, then the time taken to grant a license should be proportional to the time taken to 'ping' the server on which the license resides.

    If the checkout takes longer, DNS resolution issues can be a cause of such problems. If this is the case you can sometimes overcome the problem by substituting the server's IP address for the server name where it appears in the license search paths.

    i.e. for an environment variable 'port@servername' you can specify ' '

    or for a server line in the license file of the form:

       SERVER servername 123a456b789c 8224

    you can specify:

       SERVER 123a456b789c 8224

    This usually solves the problem.

  • Check for server issues, particularly if you have set up ARMLMD_LICENSE_FILE  to point to multiple servers.

    If any of the license search paths points to a server which is no longer running the license managment software then this will cause a delay while FLEXlm waits for the license request to time out before moving onto the next location in the search path. You should ensure that there are no spurious entries here which may cause such a delay.

    There can be a problem if you are using a triple server licensing model and the first server listed in the license file is not currently running. If this is the case the FLEXlm tools will wait until a request to this server has timed out. To work around this problem, simply edit the order of the servers in the ARMLMD_LICENSE_FILE  variable on the client computer. 

Article last edited on: 2008-09-09 15:47:32

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