tomcat5.5 clustering

There are two types of mode in which most of the servers can run.

1) HA (High Availablity) : For example - Two tomcat running and both are active.LoadBalancer distributes the request in order to manage load.If one goes down, then LB sends the request to only Avtive tomcat.

2) FT (Fault Tolerence) : For Example : Two Tomcat running in which one is active and other one is standby.Here I am not considering LB in the picture.Reuest comes on FIP( floating ip ) and if active tomcat goes down then standby tomcat will become an active tomcat now, FIP will be switch over to newly became active tomcat and now this tomcat handle the request.

I have searched on net and in most of the cluster confuguration discribes according to the first point(HA).Can we configure Tomcat in FT mode.

I also want to know how one tomcat will get to know that other tomcat is down.This may b开发者_如何学运维e by pings messages they sends to eachother.But there must be some callback on some method from tomcat source(some event may generate).Can anyone having this knowledge.

Thanks,

Vikas Jain