HA clustering issues

Hi!

The HA clustering seems as appropriate solution for a specific application
server I need to employ. An FTP server, web server and a bunch of specific
applications require (extremely) high-availability for their clients (the
cluster is taken into account basically due to the redundancy). Since I've
never worked on any HA clustering I would appreciate any books and links to
study the possible solutions (although I've been searching the Net for some
time).

I have a few specific questions regarding our potential HA cluster and I'd
be very grateful if somebody would be able to give me an answer.
Specificaly, our cluster needs to be connected on a 2 separate LANs acting
as a cluster on both. Considering that the cluster will consist of 2
machines an example of such a configuration would be:



-----------LAN1--------------

| |

NodeA ----O---- NodeB

| |

-----------LAN2-------------

In addition, the cluster should be represended by single IP address on LAN
1, and by other (single) IP address on LAN 2. All cluster applications
should be available to clients which are either on LAN 1 or LAN 2.

1) I wonder if this configuration is possible/recommended at all?

2) I'd appreciate if somebody could point out any potential issues/problems
with such a configuration?

3) What would be the switchover time (order of magnitude - 5s/30s/5min) for
an egg. web server running on a cluster (considering reasonable fast HW)
when there's a complete failure on current main node?

Thanks,

Jurica Baricevic