Abstract: A method implemented by a first controller in a software defined networking (SDN) network to monitor a health of a second controller, where the first controller and the second controller are part of a cluster of controllers, where controllers in the cluster communicate with switches over an in-band network, and where controllers in the cluster communicate with each other over an out-of-band network. The method includes sending a first control message to a switch over the in-band network in response to a determination that the second controller cannot be reached over the out-of-band network, where the first control message includes a health check request message and an instruction for the switch to send the health check request message to the second controller, and where the switch is a designated switch that has a control channel connection to the first controller and the second controller over the in-band network.

Abstract: Exemplary embodiments include methods and/or procedures for handling messages from one or more data-plane nodes (DPNs) to a plurality of controller nodes configured in a cluster, comprising: receiving a message from a DPN; tagging the message with an incarnation identifier (IID) associated with the DPN; and performing HD handling of the tagged message, which includes comparing a value of the IID of the tagged message with a value of a global IID associated with the DPN, discarding the tagged message if the value of the IID of the tagged message is less than the value of the global IID, and processing the tagged message if the value of the IID of the tagged message is not less than the value of the global IID. Exemplary embodiments also include controller nodes, controller clusters, and computer-readable media embodying operations of the exemplary methods and/or procedures.

Abstract: A method implemented by a first controller in a software defined networking (SDN) network to monitor a health of a second controller, where the first controller and the second controller are part of a cluster of controllers, where controllers in the cluster communicate with switches over an in-band network, and where controllers in the cluster communicate with each other over an out-of-band network. The method includes sending a first control message to a switch over the in-band network in response to a determination that the second controller cannot be reached over the out-of-band network, where the first control message includes a health check request message and an instruction for the switch to send the health check request message to the second controller, and where the switch is a designated switch that has a control channel connection to the first controller and the second controller over the in-band network.

Abstract: Exemplary embodiments include methods and/or procedures for handling messages from one or more data-plane nodes (DPNs) to a plurality of controller nodes configured in a cluster, comprising: receiving a message from a DPN; tagging the message with an incarnation identifier (IID) associated with the DPN; and performing HD handling of the tagged message, which includes comparing a value of the IID of the tagged message with a value of a global IID associated with the DPN, discarding the tagged message if the value of the IID of the tagged message is less than the value of the global IID, and processing the tagged message if the value of the IID of the tagged message is not less than the value of the global IID. Exemplary embodiments also include controller nodes, controller clusters, and computer-readable media embodying operations of the exemplary methods and/or procedures.

Abstract: Methods and apparatuses for autonomous relay of statistics from a network device to a network controller of a software-defined networking (SDN) network are described. The network controller is operative to transmit a message including a statistics profile, where the statistics profile includes a type of data to be collected associated with a behavior of a flow at the network device and a set of one or more criteria; where the message causes the network device to transmit a statistics message associated with one or more flows when the one or more flows satisfy at least one criterion from the set of one or more criteria, where the statistics message includes data collected at the network device associated with a behavior of the one or more flows as identified by the type of data to be collected included in the statistics profile.

Abstract: Methods and apparatuses for autonomous relay of statistics from a network device to a network controller of a software-defined networking (SDN) network are described. The network controller is operative to transmit a message including a statistics profile, where the statistics profile includes a type of data to be collected associated with a behavior of a flow at the network device and a set of one or more criteria; where the message causes the network device to transmit a statistics message associated with one or more flows when the one or more flows satisfy at least one criterion from the set of one or more criteria, where the statistics message includes data collected at the network device associated with a behavior of the one or more flows as identified by the type of data to be collected included in the statistics profile.

Abstract: A method is performed by a controller node to support network element (NE) data migration. The controller node is part of a cluster of controller nodes in a software defined networking (SDN) network. The method includes detecting that a peer controller node in a same replication zone as the controller node has failed, where the peer controller node is a master for data associated with an NE and the controller node is a backup for the data associated with the NE, transitioning a state of the NE to a migration state, transferring the data associated with the NE from backup storage (Zb) of the controller node to dead storage (Zd) of the controller node, receiving a request for the data associated with the NE from a requesting controller node, and transferring at least a fragment of the data associated with the NE to the requesting controller node.