In this paper, we propose a low-overhead recovery algorithm based on a quasisynchronous
checkpointing algorithm. The checkpointing algorithm preserves process
autonomy by allowing them to take checkpoints asynchronously and uses communicationinduced
checkpoint coordination for the progression of the recovery line which helps
bound rollback propagation during a recovery. Thus, it has the easeness and low overhead
of asynchronous checkpointing and the recovery time advantages of synchronous
checkpointing. There is no extra message overhead involved during checkpointing and
the additional checkpointing overhead is nominal. The checkpointing algorithm ensures
the existence of a recovery line consistent with the latest checkpoint of any process all
the time. The recovery algorithm exploits this feature to restore the system to a state
consistent with the latest checkpoint of a failed process, in the event of a failure. The
recovery algorithm has no domino effect and a failed process needs only to rollback to its
latest checkpoint and request the other processes to roll back to a consistent checkpoint.
It uses selective pessimistic message logging at the receiver end to handle the messages
lost due to rollback. Neither the recovery algorithm nor the checkpointing algorithm
requires the channels to be FIFO. We do not use vector timestamps for determining dependency
between checkpoints which result in high message overhead during failure-free
operation if the number of processes is large.