[squid-users] Squid reverse proxy load balancing

I've got squid running as a reverse proxy, terminating HTTPS requests
and forwarding them to HTTP(S) servers on the inside. I've now gotten a
request to use this same proxy to load balance requests between multiple
internal servers. It looks like you can do this by specifying two
"cache_peer" lines with different IP's, and putting the "round-robin"
flag on them, like this:

 cache_peer InsideIP1 parent 80 0 no-query originserver login=PASS name=InsideName-peer round-robin
 cache_peer InsideIP2 parent 80 0 no-query originserver login=PASS name=InsideName-peer round-robin

Using this setup, what will happen if one of those servers goes down?
Will half of the requests fail, or will squid transparently resend the
request to the working server?

Is there any way to specify automatic connection persistence, where all
requests from a certain client will go to the same back end server so as
to maintain session state & the like? I don't want to split them up
manually using ACL's; I want squid to do this for me while allowing for
down servers (see above).