When you install the first Connection Server you install it as a standard instance. Subsequent ones in the group are installed as replica instances so that they all operate as a group sharing configuration data and operations.
Whether a Connection Server was installed as a standard instance or replica instance is just an install time concept. Once they are installed, all Connection Servers are equal. In answer to your question, there is no concept of a "Master" Connection Server.
Configuration data on each Connection Server is stored in a local LDAP directory and this data is replicated between Connection Servers using standard LDAP replication so that it is shared and the same data is therefore available to all Connection Servers.
In addition to LDAP replication data, JMS messaging is used between Connection Servers to communicate live state information and to control which Connection Server takes on particular tasks such as pool management etc. This is dynamic so that if a Connection Server goes down, one of the others can take on the task. This is all managed automatically by View itself.
All Connection Servers can send events to the Event Database.
Take a look at the View 5.1 Architecture Planning Guide for more info on this - http://pubs.vmware.com/view-51/topic/com.vmware.ICbase/PDF/view-51-architecture-planning.pdf There is also a section on "View Connection Server Cluster Design Considerations".
Mark