Temporary failures are handled by retrying. A node persistently
logs any outstanding remote-operation requests, such as
contents update, random walk, or edge addition.
A node retries logged updates upon reboot or after
it detects another node's recovery.
This recovery logic may sometimes create uni-directional edges
or more edges than desired, but it maintains the
most important invariant, that the graphs are 
-connected and that
all replicas are reachable in the hierarchical name space.
Pangaea reduces the logging overhead during contents-update flooding, by logging only the ID of the modified file and keeping deltas only in memory. To reduce the memory footprint further, when a node finds out that deltas to an unresponsive node are piling up, the sender discards the deltas and falls back on full-state transfer.