Patent ID: 9172663
Filing Date: 2015-10-27
Classification: G06F,H04L

Abstract:
1. A non-transitory machine readable medium storing a program which when executed by at least one processing unit provides a first controller instance of a plurality of controller instances in a network control system, the plurality of controller instances for managing switching elements, each controller instance having (i) a network information base (NIB) storage that comprises a first set of modules for communicating with secondary storages of other controller instances in the plurality of controller instances and that stores a plurality of data records regarding a plurality of switching elements in a NIB storage structure in a volatile memory and (ii) a secondary storage that comprises a second set of modules for communicating with the NIB storages of other controller instances in the plurality of controller instances and that stores a copy of a set of the plurality of data records stored in the NIB storage structures in a transactional database in a non-volatile memory, the program comprising sets of instructions for: at the secondary storage of the first controller instance, receiving notification from a NIB storage of a second controller instance of the plurality of controller instances that a data record has changed in the NIB storage structure at the second controller instance; and from the secondary storage of the first controller instance, using the second set of modules to direct a NIB storage of a third controller instance of the plurality of controller instances to replicate the change to the data record in order to replicate at least a portion of the data records in the NIB storage structure of the second controller instance across the NIB storages of other controller instances in the plurality of controller instances.