Planning for Business Continuity
Based on your current Skype-for-Business environment it is possible to define a scenario that most-likely best suits your organization needs on Business Continuity with Anywhere365. Answer the questions in the flowchart below and find out how Anywhere365 can be implemented within your organization.
Note This is only a single example of how Anywhere365 can be configured within your organization. Multiple scenario’s might be applicable.
Per scenario three different elements will be distinguished:
- High-Availability: two or more servers that can take over from each other if one of the servers is shut down (either planned or unplanned) in a (semi-)automatic way.
- Disaster Recovery: a replication of the server configuration on a second node that can take over in case of emergency, after a manual failover.
- Load Balancing: two or more A365 pools for load-balancing the amount of conversations within your organization.
In this scenario, there is no second node, no multiple pools and all server roles are stand alone. Therefore the Anywhere365 components can be standalone as well.
Because all servers within the node are high-available, it is best to make Anywhere365, SharePoint and SQL High-Available as well. In this scenario the High-Availability configuration for SQL is an AlwaysOn Cluster, another possibility is a SQL Mirror instead.
Since there are multiple Front End Pools within the Skype for Business Topology, it is assumed that the Skype for Business Users are spread across these multiple Pools as well for load balancing the activities of these users. In this case, it might be useful to have two Anywhere365 pools as well for load balancing the conversations.
These two pools can be used either in an Active-Active situation or an Active-Passive situation in which the Passive pool can take over the activities of the Active pool after a manual failover (when the A365 Sync script is in place). This might be useful for maintenance in both Anywhere365 as well as Skype for Business itself.
In this fourth scenario both the activities on the Anywhere365 server are load balanced in a similar fashion as the activities of the Skype for Business Users and also the different server roles (A365, SP, and SQL) are High-Available within the node.
So, if one server in any of the roles fails, the operations can continue, also if one of the Skype for Business Pools or A365 pools are out-of-service, a manual failover can be initiated.
Again, the SQL AlwaysOn Cluster can be replaced by a SQL Mirror instead.
As soon as a secondary Node is in play it becomes possible to use this Node for Disaster Recovery purposes. If the primary Node goes black, the secondary Node can take over. Both Nodes can be used Active-Active, as well as Active-Passive.
Ideally, SharePoint, used for settings management, should contain the same data on both nodes, in order to minimize the impact in case of failover. To sync two SharePoint Servers, it is possible to create custom-made scripts, but it is better to generate a Stretched SharePoint Farm over two nodes in combination with a SQL Mirror. For more information see: http://blogs.msdn.com/b/zwsong/archive/2011/04/04/killing-two-birds-with-one-stone-sharepoint-ha-and-dr-with-stretch-farm-and-everything-you-want-to-know-about-it.aspx
Because the Anywhere365 server roles are not High-Available in this scenario, we choose to configure them as an Active-Passive pair. As said before, it can also be an Active-Active pair.
Scenario 6 is similar to scenario 5, the only difference is that not only Disaster Recovery is possible, but also that server roles within each node are High Available. In this case, downtime is minimized because there is no need for manual failover to the secondary Node if minor problems, which can be solved by the server pools, are present within the primary Node.
Because a SQL Mirror might have data loss if a failover from the Principal Server to the Mirror Server is initiated, and this scenario is completely High Available, it is better to have a SQL Always-On Cluster over the two nodes. For more information about Building a High-Availability and Disaster Recovery Solution by using Failover Cluster Instances and Availability Groups please visit: https://msdn.microsoft.com/en-us/library/jj215886.aspx
The final two scenario’s combine Disaster Recovery with Load Balancing for the conversations of Anywhere365. In this scenario, server pools are not High- Available a failover can be initiated from one of the two A365 Pools on the same Node, as well as from the primary Node to the secondary Node.
This makes it possible to mix-and-match Active- and Passive servers into a preferable configuration. In the picture below, the active servers are placed in the first A365 Pool on the primary Node and the second A365 Pool on the secondary Node, and the passive servers are placed in the second A365 Pool on the primary node and the first A365 Pool on the secondary Node. The combination of active and passive servers in different Pools on different Nodes makes it possible to do a failover to any of the passive servers.
This last scenario defines the most extensive A365 configuration that you can have. There are multiple Skype for Business Front End Pools linked to Anywhere365 Pools for Load Balancing of all calls that take place. Furthermore, every Pool is High-Available on itself, and can be failed over to another Pool on the same Node as well as to a complete other Node.
Also, the SharePoint Farm is stretched over the two Nodes and each node has multiple SharePoint Front End servers for the best availability of your UCC Settings. Finally, the SQL Servers are placed in an Always-On Cluster over multiple Nodes.
This provides a solution in which all conversations can be Load Balanced, all server roles are High-Available for minor problems and maintenance, and Disaster Recovery can take place in case of emergency.
High Availability and Disaster Recovery are two different elements of Business Continuity. Anywhere365, and all of its components, support multiple High Availability and Disaster Recovery scenarios. In order to gain the highest level of up-time possible, select and design the scenario that fits your business requirements best and make sure that your Skype for Business environment, in combination with Anywhere365, operates continuously.