Tarragon supports 3 kinds of redundancy:

• Clients can select 1 of N Web servers
• Real time data can be read from 1 of 2 redundant databases
• Measurement data can be read from 1 of 2 redundant OPC servers

When a Web server is down the client will automatically fall over to another Web server.

When a Web server/database is down, it will replicate data from the other database when restarted. Every 15 minute the databases will exchange data to become equal.

There can be N pair of OPC-servers providing data to TarraStore, one of the servers are master, while the server standby will become master when the current master shuts down.