When an application server, say Server1, fails, the following occurs:
- The connections from the client will also fail.
- Other connections through TSA1 to Server2 and Server3 will survive.
- Clients who were sending traffic to the failed application server must send traffic to their secondary TSA (TSA2).
- IPFE-A1 will route new connection requests to the remaining application servers (Server2 and Server3). If all application servers in a target set fail, and IPFE-A1 receives a request for a new connection to TSA1, it will optionally notify the client that the request cannot be fulfilled, using either a TCP RST packet (for TCP connections), or a configurable ICMP message.
When Server1 recovers:
- IPFE-A1 will detect Server1's availability.
- IPFE-A1 will route new connection requests to Server1.
- Some imbalance across application servers in TSA1 will exist after recovery. IPFE-A1 will monitor for imbalances in traffic and distribute new connections to reduce the imbalance.