Abstract: A control system that includes several controllers for managing several switching elements. A first controller receives a request to modify a data tuple stored in a network information base (NIB) storage of the first controller that stores data for managing a set of switching elements. The first controller determines whether the received request to modify should be processed by the first controller. When the received request should be modified by the first controller, the first controller modifies the set of data in the NIB storage. The first controller updates a request list that is propagated between the controllers to disseminate requests to modify different data tuples that are stored in the NIB storages of the different controllers.

Abstract: A network control system that includes several controllers for managing several switching elements. Each controller includes a network information base (NIB) storage that stores data regarding the switching elements and a secondary storage for facilitating replication of at least a portion of data across the NIB storages of the different controllers. In some embodiments, the primary purpose for one or more of the secondary storage structures is to back up the data in the NIB. In these or other embodiments, one or more of the secondary storage structures serve a purpose other than backing up the data in the NIB. In some embodiments, the NIB is stored in system memory while the system operates for fast access of the NIB records. In some embodiments, one or more of the secondary storage structures are stored on disks which can be slower to access.

Abstract: A control system including several controllers for managing several switching elements. A first controller registers a second controller for receiving a notification when a data tuple changes in a network information base (NIB) storage of the first controller that stores data for managing a set of switching elements. The first controller changes the data tuple in the NIB. The first controller sends the notification to the second controller of the change to the data tuple in the NIB. The first and second controllers operate on two different computing devices. Each controller receives logical control plane data for specifying logical datapath sets and converts the logical control plane data to physical control plane data for enabling the switching elements to implement the logical datapath sets.

Abstract: A network control system that includes several controllers for managing several switching elements and a distributed hash table (DHT) formed across the controllers for storing data regarding the switching elements that is accessible by the controllers. Each hash table serves as a DHT instance. In some embodiments, the DHT instances of all controller instances collectively store one set of records that is indexed based on hashed indices for quick access. These records are distributed across the different controller instances to minimize the size of the records within each instance and to allow for the size of the DHT to be increased by adding other DHT instances. According to this scheme, each DHT record is not stored in each controller instance. In fact, in some embodiments, each DHT record is stored in at most one controller instance.

Abstract: Some embodiments provide a system for managing several switching elements. The system includes a network information base (NIB) data structure for serving as a primary storage structure for storing data for managing the several switching elements. The system includes a secondary storage structure for storing a copy of a set of data stored in the primary storage structure for managing the several the switching elements.

Abstract: Some embodiments provide a program for managing several switching elements. The program receives, at a network information base (NIB) data structure that stores data for managing the several switching elements, a request to notify a first application that uses the NIB when a set of data stored in the NIB is changed. The program changes, in response to an instruction from a second application, the set of data in the NIB. The program sends a notification to the first application of the change to the set of data in the NIB.