Failover Licenses

  • alanbarclay
Posted: Wed, 11/04/2009 - 13:00

The Reprise License Manager (RLM) used to license RTDA software supports redundant licensing for continued availability when the primary license host has crashed or is off the network.

In contrast to triple-redundant, or triad, license servers supported by FLEXlm, RLM uses a single failover license server. This failover server can support multiple primary servers.

However, it does not protect against RLM not running on the primary host. It only protects against machine crash or network problems that cause the primary host to be off the network.

You must prepare ahead of time to support license failover by selecting a failover host, and obtaining a failover license. Also, you must set the RLM_LICENSE environment variable to include the failover port@host before starting the RTDA tools. For example, a non-redundant setup might set RLM_LICENSE to 7070@bison. If your failover license server is named cheetah you would set RLM_LICENSE to 7070@bison:7070@cheetah.

In the above example, the contents of the RLM failover license on host cheetah would look something like:

HOST cheetah <cheetah-hostid> 7070
ISV rtdad ./rtdad
LICENSE rtdad rlm_failover 1.0 permanent 1 hostid=bison-hostid \
    _failover_host=bison sig="<complicated-alphanum-string>"

WARNING There is a problem in RLM that causes file descriptors to be leaked when the RLM_LICENSE variable includes a failover port@host but no RLM server is running there.

This will eventually cause the vovserver to become non-responsive when file descriptors are exhausted. you can identify the problem by examining the most recent vovserver log file
<project>.swd/logs/server.YYYY.MM.DD.log and searching for 'too many open files'.

If you plan to use RLM failover, we recommend that you set it up all at once, before starting the RTDA software. If this is not possible, please see the Note below.

Guru Note: It is possible to change a vovserver from non-redundant to failover licensing on the fly without a shutdown.

After you have started the failover RLM license server and confirmed that it is running, use the following commands:

% source /path-to-rtda/common/etc/vovrc.{csh,sh}

To get the RTDA commands in your PATH;
(use the one for your shell type)

% vovproject enable project-you-want-to-change
% vovsh -Y 'puts [vtk_server_setenv RLM_LICENSE port@primary:port@failover]'

You can confirm that the server environment was changed by pointing your web browser to

  http://server-host:server-port/server?page=environment

Substitute the values of your vovserver host name and port.