Puppet users - Oct 2007 - puppet with squid proxy

hi ,all
     when the puppetmasterd run in mongrel type ,can use the squid as
the https proxy ? but I remember that the squid 2.5 can''t authorize
the client''s certificate.  but can use the squid 2.6 do it ?
is there have some one to had done it ?
and if the host  more than 1000, how to make a puppet HA or cluster .

-- 
Huang Mingyou