.. include:: ../general/failover-server.rst

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Special notes on rlm_failover_server_activate licenses
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The *rlm_failover_server_activate* license requires a machine which can connect to the internet to operate.
Before serving licenses, the failover server must activate its special license (an *rlm_failover_auth* license)
before it will begin to serve licenses from the primary server's license file. The server will log a warning at
startup if there is an *rlm_failover_server_activate* license in its license file but it cannot verify that the
activation key is good (the server calls rlm_act_keyvalid() to validate the key).

.. note:: When you create the activation key to be used with the rlm_failover_server_activate
   license, specify a product name of “rlm_failover_auth”, and a nodelocked, uncounted
   license. Your ISV server will pass the failover server's hostid as the hostid in this
   activation request.

.. note:: Reprise Software recommends setting _primary_server to **localhost** (or **5053@localhost**) when
   issuing the *failover* license. This value would be changed by the license administrator to the name of the
   *primary server* upon installation. Setting this to **localhost** ensures that the *failover license server* 
   will not be activated by mistake if the license is not edited.

The **failover license** must be a **counted** license; otherwise, the server will not use it. (If it were not a
counted license, the **failover license** could be used on any server, which could result in multiple servers
taking over **at the same time** for the primary server.)

In order to enable the *failover license server*, the **failover license** needs to be in one of the license files 
it is using, and the license file(s) for the *primary server* also need to be processed by the *failover license server*.

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When a license server encounters a failover license, it does several things:
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* Starts a separate thread in the license server to periodically monitor the health of the
  *primary server*:

	* If the license is an *rlm_failover* license, the failover server attempts to determine
	  whether the license server *machine* is running, by connecting to ports on that machine. If the
	  license server machine is up but the license server is not running, the failover license server
	  will **not** take over serving licenses.
	* If the license is an *rlm_failover_server* license, the failover server attempts to
	  connect to the main RLM port on the primary server. The main RLM port is specified in
	  _primary_server on the rlm_failover_server license, or defaulted to port 5053 if not specified. 
	  If the failover machine cannot connect to the RLM process on the primary server, the failover 
	  server takes over.

* If the primary server should go down, enables all licenses in license files for the *primary*
  *server* by performing the equivalent of an *rlmreread* command. In the case of an
  *rlm_failover_server_activate* license, the failover server will attempt to activate its license from the
  Activation Pro server before proceeding. If successful, it will serve the primary server's licenses,
  otherwise it will not.
* When the *primary server* comes back up, disables all licenses in license files for the *primary*
  *server* by performing the equivalent of an rlmremread command.

.. note:: Failover License Servers are by no means secure and are intended to be used by trusted
   customers. If the _primary_server value is set to a non-reachable system name/server, the
   Failover License Server will always serve the licenses from the primary server. The 
   rlm_failover_server_activate license at least informs you when this is happening via the
   fulfillment logs in ActPro.