Class MERGE3

Protocol to discover subgroups; e.g., existing due to a network partition (that healed). Example: group {p,q,r,s,t,u,v,w} is split into 3 subgroups {p,q}, {r,s,t,u} and {v,w}. This protocol will eventually send a MERGE event with the coordinators of each subgroup up the stack: {p,r,v}. Note that - depending on the time of subgroup discovery - there could also be 2 MERGE events, which first join 2 of the subgroups, and then the resulting group to the last subgroup. The real work of merging the subgroups into one larger group is done somewhere above this protocol (typically in the GMS protocol).

This protocol works as follows:

• If coordinator: periodically broadcast a "I'm the coordinator" message. If a coordinator receives such a message, it immediately initiates a merge by sending up a MERGE event

  Provides: sends MERGE event with list of coordinators up the stack
  

public void down(Event evt)

public String getName()

public void init()
            throws Exception

public boolean setProperties(Properties props)

public void startDownHandler()

public void startUpHandler()

public void up(Event evt)