I'm not sure if this is the correct forum; however, I didn't see anywhere else to ask this question. If it should be some place else, please let me know.

If I have a configuration where the Load Balancer (LB) is pointing to 2 WebServers (WS) which points to 2 AppServers (AS):

LB
/ \
WS1 WS2
| |
AS1 AS2

For failover purposes, WS1 has connections to both AS1 and AS2. And, WS2 has connections to both AS1 and AS2--Load balancing in a cluster and failover environment. The single point of failure looks to be from the LB to the WS. I have several questions.

1). If content is kept on the webservers and WS1 crashes, what happens to a session that is in the middle of processing? Will they experience an outage? Would they have to start over?

2). If content was kept on the application servers, again what happens to a session that was in the middle of processing? And what kind of outage would occur, if any.

3). Do anyone know of a solution to cover LB and failover--i.e., the transaction runs seamlessly in case of a server outage/

Thank you,