There are two ways to set a failover SharePoint environment. This is also known as SharePoint disaster recovery plan. In case your farm goes down, you should have options to make it up in few seconds,minutes, hours or days depending on the approach which you select.
This approach can be applied to both SharePoint 2010 and SharePoint 2013. However, i haven't applied any of this approach to any of my SharePoint farm but will apply soon in future and write down another post with my findings. Below stuff i have collected from Microsoft blogs to define a very upper level view of both approaches.
1. Set a failover DB server
2. Build a hot standby SharePoint Farm
Set a Failover DB Server
- Only one SharePoint farm.
- Require an additional DB server along with a witness sql server.
- It uses Database mirroring and only DB level backup exists in case of failure.
- If any WFE or APP server get down or offline, you'll need to build that server again or fix the problem which may effect the traffic and have a downtime of hours or days, depending on the problem.
- This approach can be used where you can buy time from client or users in setting up the farm.
- Can take from minutes to days to recover from any outage.
Hot-Standby SharePoint Farm
- Using AlwaysOn SQL feature (Enterprise version only).
- Consists of two parallel SharePoint farms.
- Requires equal number of servers with same roles in secondary farm as in primary farm. (as best approach)
- All custom installations must be done on both farms.
- Farm level DB and file system backups exists in case of failure.
- Easy to switch on secondary farm in case of expected/unexpected outage.
- In case any server in primary farm get down or offline, users can be switched to secondary farm immediately by changing IP's in DNS(slow process) or in NLB(fast process).