The failure detection layer (FD) periodically tries to reach its nearest neighbor to the right (see fig. 7.1.
The nearest neighbor is always computed based on the local view. Since all views in all stacks have the same member ordering, every member can always determine its next neighbor to the right. When a new view is received, the neighbor is recomputed.
The FD layer periodically pings its neighbor. When no response has been received after max_tries (each with a timeout), a SUSPECT message is multicast to all members of the group. The GMS layer which is currently the coordinator processes the message, all others ignore it7.1. In the example, the coordinator would be A. It pings B which in turn pings C. The last member ( E) 'wraps around' and pings the first (A).
