WAN recovery provides a readily available backup server which will take over operations when the active server or application fails.
Replication is required to make sure that the data on the backup server is up-to-date. Multi-node solutions are also possible, but to simplify the description, a 2-node solution is described.
The solution works as follows:
Set up servers at both sites to mirror changes between the servers.
Monitor both servers with LifeKeeper to detect any application or hardware downtime
Failover to the backup server if there any disruption in service to your users
Fix any problems which occurred while users are using the backup server
Returning the faulty server back to service, will cause the data replication to resynchronize
Once data is resynchronised, the original server can become the active server once again
Failover does not affect clients
When the application migrates to the standby server, LifeKeeper also migrates IP addresses and hostnames ensuring that clients normally do not even notice the failover, and at worst are simply required to reconnect to the server to re-establish their session.
Advantages of the 2-node approach:
1. Minimises hardware and licensing costs.
2. Ensures off-site, real-time backups of all critical data.