Failover and Recovery
Failover and Recovery
| RTR provides several capabilities to ensure failover and recovery |
| under several circumstances. |
Router Failover | Frontend nodes automatically connect to another router if the |
| one being used fails. This reconnection is transparent to the |
| application. |
| Routers are responsible for coordinating the |
| for transactions. If the original router coordinating a transaction |
| fails, backend nodes select another router that can ensure correct |
| transaction completion. |
Backend | Transactions in the process of being committed at the time of a |
Restart | failure are recovered from RTR's disk journal. Recovery could be |
Recovery | with a concurrent server, a standby server, or a restarted server |
| created when the failed backend restarts. |
| Correct ordering of the execution of transactions against the |
| database is maintained. |
Transaction | Transaction messages which are lost in transit are |
Message | possible. The frontend and backend nodes keep an |
Replay | copy of all active messages for this purpose. |
Link Failure | In the event of a communications failure, RTR tries to reconnect |
Recovery | the link or links until it succeeds. |
Recovery Scenarios
This section describes how RTR recovers from different hardware and software failure. For additional information on failure and recovery scenarios, see the RTR Application Design Guide.
