Edge Server Disaster Recovery
Topic Last Modified: 2013-11-11
As with other server roles, the best way for you to provide high availability for your Edge Servers is to deploy multiple Edge servers in pools in each site. If one Edge Server goes down, the other servers in the pool will continue to provide Edge services.
To enable disaster recovery procedures, you must have separate Edge Server pools deployed at separate sites. You do not need to explicitly pair Edge pools together as you do with Front End pools, but having multiple Edge pools still provides the availability to carry on if one entire Edge pool goes down. The following sections provide details on disaster recovery for the various functions of Edge Servers.
If you have multiple sites, each with a pool of Edge Servers, and one entire Edge pool fails, the remote access services will continue to function without needing administrator actions. Remote users will automatically be routed to the Edge Servers in another site, because all Edge Server pools in your organization have the same external FQDN.
To ensure that this automatic failover will work smoothly, be sure to add every Front End pool in your organization to the publishing rules on the Reverse Proxy at each site. This way, Front End Servers in one site can communicate with Edge Servers in every other site, if the Edge Servers in the same site as the Front End Servers are unavailable.
For federation relationships with other organizations running Lync Server, inbound federation requests will continue to work as long as you have configured each Edge pool to have a different priority in your SRV records. Any federation requests that come to an Edge pool that is down will fail back and then connect to an Edge pool which is running.
Outbound federation is always set up through one published Edge pool or Edge Server in the organization. If this Edge pool has gone down, you must use Topology Builder to change the outbound federation route to use an Edge pool which is still running. For details, see Failing Over the Edge Pool Used for Lync Server Federation
For XMPP federation, both outbound and inbound traffic will fail if the Edge pool which is designated as the XMPP federation gateway goes down. To make XMPP federation work again, you must change XMPP federation to use a different Edge pool. For details, see Failing Over the Edge Pool Used for XMPP Federation.
If an Edge pool fails at a site, but the Front End pool at that site is still running, you will need to change the Front End pool to use a different Edge pool at a different site while that first Edge pool is down. For more information, see Changing the Edge Pool Associated with a Front End Pool.