Overview of common application problems

Split Brain scenarios occur when certain sets of machines in a distributed system become unable to communicate with each other and begin to act independently, often, when not handled correctly, causing data corruption.

Split Brain scenarios arise when machines providing certain kinds of fault tolerant services lose communication with each other but decide to continue operating independently. When different parts of the system diverge, the various groupings of machines may decide that the other groups have failed, even though such groups are actually still running and servicing requests. When this happens, both groups of machines may start to operate authoritatively for the service they provide causing contradictory changes to occur.