Patent ID: 9432252
Filing Date: 2016-08-30
CPC Classification: G06F,H04L

Claim Text:
1. For a first controller instance that manages a first set of forwarding elements implementing logical datapath sets of a network control system, a machine-readable medium storing a program executable by at least one processing unit of the first controller instance, the program comprising sets of instructions for: maintaining a first set of forwarding state data that represents a forwarding state of the first set of forwarding elements; receiving a second set of forwarding state data that represents a forwarding state of a second set of forwarding elements from a second controller instance; propagating the first set of forwarding state data to the first set of forwarding elements; upon detecting a failure of the second controller instance, merging the second set of forwarding state data into the first set of forwarding state data to produce a third set of forwarding state data; and propagating the third set of forwarding state data to the first and second sets of forwarding elements.