Abstract: A standby database cluster takes on the role of the primary database cluster if the primary database cluster becomes unavailable using the following steps: (i) operating a database management system (DBMS) including an initial primary cluster and a plurality of standby clusters; (ii) communicating to a set of client driver(s) connecting a first application to the initial primary cluster an identity of the plurality of standby clusters; (iii) on condition that the initial primary cluster becomes unavailable, assigning a selected standby cluster of the plurality of standby clusters to be assigned as a new primary cluster in place of the initial primary cluster; and (iv) in response to assignment of the new primary cluster, seamlessly moving the first application from the initial primary cluster to the new primary cluster without any substantial human intervention.

Abstract: A method in a computing device for locality sensitive load balancing between servers includes receiving a packet and querying a plurality of Bloom filters, using keys based upon a plurality of header field values of the packet, to generate a plurality of candidate servers. A subset of the candidate servers were generated due to false positive matches occurring from some of the plurality of Bloom filters. One server of the plurality of servers is identified as the destination for the packet based upon identifying the subset of candidate servers within an entry of a false positive table. Each false positive table entry identifies, for a flow of packets, servers that are falsely included in sets of candidate servers generated by the plurality of Bloom filters for packets of that flow. The packet is transmitted to the first server.

Abstract: Methods for delay measurement in a software-defined networking (SDN) system are disclosed. In one embodiment, one packet each is received from a first and a second network device. The time stamps of these packets are recorded in a set of ingress time stamps and a set of egress time stamps respectively if the first and second network devices are the ingress and egress network devices of a traffic flow and if both packets include indications for delay measurement. Then the method continues with a delay measure for the traffic flow based on at least the sets of the ingress time stamps and egress time stamps associated with the flow identifier of the traffic flow, and a measurement noise the electronic device obtained from sending measurement packets to the first and second network devices.

Abstract: In one embodiment, a packet from a SDN controller is received at a network device. The packet is processed according to a flow table, which contains at least two entries that each matches the packet. The entries contain instructions to forward the packet according to group tables, and the entries are to expire after different time durations. The packet is to be forwarded according to a first group table and gets duplicated into two: one is transmitted to a first packet queue that transmits packets in a fixed interval to a loopback port that loops back the packets, while the other is forwarded to a first packet buffer that randomly drops packets at a probability prior to transmitting the remaining packets to generate a traffic pattern. The packet is received from the loopback port, and then forwarded according to a second group table to generate another traffic pattern.

Abstract: A method and system are implemented by a controller in a software defined networking (SDN) network. The SDN network includes a set of nodes. The controller is in communication with a server providing information about environmental events affecting the SDN network. The method includes receiving information about an environmental event affecting the SDN network, identifying a subset of the nodes in the SDN network affected by the environmental event based on location information for the subset of nodes, determining a degree of impact caused by the environmental event for each node in the subset of nodes, and configuring the SDN network to diminish an impact of the environmental event on the SDN network performance.

Abstract: A method for path monitoring is disclosed. The method includes receiving, at the network device, a packet from a SDN controller to monitor a path for a service between the network device and another network device. The method includes sending the packet to at least a first and a second port, where a first instance of the packet is transmitted to the first port to the other network device to monitor the path, and a second instance is transmitted to the second port that loops back the second instance to the network device at a transmission interval so that the packet is sent to the first port repetitively at the transmission interval. The method also includes determining whether or not the packet is received from the other network device within a timeout interval and discarding the packet upon determination that the packet is received within the timeout interval.

Abstract: In one embodiment, a packet from a SDN controller is received at a network device. The packet is processed according to a flow table, which contains at least two entries that each matches the packet. The entries contain instructions to forward the packet according to group tables, and the entries are to expire after different time durations. The packet is to be forwarded according to a first group table and gets duplicated into two: one is transmitted to a first packet queue that transmits packets in a fixed interval to a loopback port that loops back the packets, while the other is forwarded to a first packet buffer that randomly drops packets at a probability prior to transmitting the remaining packets to generate a traffic pattern. The packet is received from the loopback port, and then forwarded according to a second group table to generate another traffic pattern.

Abstract: Systems and methods of obtaining and recording fundus images by minimally trained persons, which includes a camera for obtaining images of a fundus of a subject's eye, in combination with mathematical methods to assign real time image quality classification to the images obtained based upon a set of criteria. The classified images will be further processed if the classified images are of sufficient image quality for clinical interpretation by machine-coded and/or human-based methods. Such systems and methods can thus automatically determine whether the quality of a retinal image is sufficient for computer-based eye disease screening. The system integrates global histogram features, textural features, and vessel density, as well as a local non-reference perceptual sharpness metric. A partial least square (PLS) classifier is trained to distinguish low quality images from normal quality images.

Abstract: Exposing existing database server attributes that are used for load balancing, accounting, log filtering, problem determination, and end user identification as tenant identifiers. An example of such attribute is the values in existing client information fields that are available to applications for passing additional information to the database server via connections. These values are then used by the database server for enhanced operational functions of load balancing, accounting, log filtering, problem determination, and end user identification.

Abstract: Exposing existing database server attributes that are used for load balancing, accounting, log filtering, problem determination, and end user identification as tenant identifiers. An example of such attribute is the values in existing client information fields that are available to applications for passing additional information to the database server via connections. These values are then used by the database server for enhanced operational functions of load balancing, accounting, log filtering, problem determination, and end user identification.

Abstract: A method of generating network traffic in a network device of a data communication network includes providing traffic generation parameters in the network device that describe a desired traffic pattern to be generated by the network device, generating a trigger packet in the network device, the trigger packet specifying a drop precedence for packets generated by the network device in a state defined by the trigger packet, replicating the trigger packet to provide a packet train, selectively dropping one or more packets in the packet train based on the drop precedence specified in the trigger packet, and transmitting the packet train from the network device.

Abstract: A method for generating a high-precision packet train includes configuring an initial packet generation flow of duration T in a network node and sending a packet to a loopback port to initiate the initial packet generation flow in the network node, where the loopback port loops packets back to the network node or recirculates packets within the network node, and where the loopback port is configured for traffic shaping that establishes a pre-determined inter-packet gap for packets output by the loopback port. The method further includes configuring a main packet generation flow having a duration t1 that commences on expiration of the duration T. Looped back packets in the network node are sent to the loopback port for the entirety of durations T and t1, while one copy of each looped back packet in the network node is sent to a network port during the duration t1.

Abstract: A standby database cluster takes on the role of the primary database cluster if the primary database cluster becomes unavailable using the following steps: (i) operating a database management system (DBMS) including an initial primary cluster and a plurality of standby clusters; (ii) communicating to a set of client driver(s) connecting a first application to the initial primary cluster an identity of the plurality of standby clusters; (iii) on condition that the initial primary cluster becomes unavailable, assigning a selected standby cluster of the plurality of standby clusters to be assigned as a new primary cluster in place of the initial primary cluster; and (iv) in response to assignment of the new primary cluster, seamlessly moving the first application from the initial primary cluster to the new primary cluster without any substantial human intervention.

Abstract: A standby database cluster takes on the role of the primary database cluster if the primary database cluster becomes unavailable using the following steps: (i) operating a database management system (DBMS) including an initial primary cluster and a plurality of standby clusters; (ii) communicating to a set of client driver(s) connecting a first application to the initial primary cluster an identity of the plurality of standby clusters; (iii) on condition that the initial primary cluster becomes unavailable, assigning a selected standby cluster of the plurality of standby clusters to be assigned as a new primary cluster in place of the initial primary cluster; and (iv) in response to assignment of the new primary cluster, seamlessly moving the first application from the initial primary cluster to the new primary cluster without any substantial human intervention.

Abstract: Aspects of a high-precision packet train generation process are distributed among several distinct processing elements. In some embodiments a control processor configures a packet-processing unit with a packet train context that includes details such as the number of packets to be generated and the headers to be included in the packets. The packet-processing unit takes a packet to be used in the packet train and recirculates it a number of times, as specified by the packet train context. The recirculated packets, with the appropriate headers inserted, are forwarded to a traffic-shaping queue in queuing hardware. The traffic-shaping queue is configured to output the forwarded packets with a constant inter-packet gap. Thus, the generation of the multiple packets in the packet train is handled by the packet-processing unit, while the precise inter-packet timing is provided by the traffic-shaping queue in the queuing hardware.

Abstract: A method in a computing device for locality sensitive load balancing between servers includes receiving a packet and querying a plurality of Bloom filters, using keys based upon a plurality of header field values of the packet, to generate a plurality of candidate servers. A subset of the candidate servers were generated due to false positive matches occurring from some of the plurality of Bloom filters. One server of the plurality of servers is identified as the destination for the packet based upon identifying the subset of candidate servers within an entry of a false positive table. Each false positive table entry identifies, for a flow of packets, servers that are falsely included in sets of candidate servers generated by the plurality of Bloom filters for packets of that flow. The packet is transmitted to the first server.

Abstract: A method of generating network traffic in a network device of a data communication network includes providing traffic generation parameters in the network device that describe a desired traffic pattern to be generated by the network device, generating a trigger packet in the network device, the trigger packet specifying a drop precedence for packets generated by the network device in a state defined by the trigger packet, replicating the trigger packet to provide a packet train, selectively dropping one or more packets in the packet train based on the drop precedence specified in the trigger packet, and transmitting the packet train from the network device.

Abstract: Aspects of a high-precision packet train generation process are distributed among several distinct processing elements. In some embodiments a control processor configures a packet-processing unit with a packet train context that includes details such as the number of packets to be generated and the headers to be included in the packets. The packet-processing unit takes a packet to be used in the packet train and recirculates it a number of times, as specified by the packet train context. The recirculated packets, with the appropriate headers inserted, are forwarded to a traffic-shaping queue in queuing hardware. The traffic-shaping queue is configured to output the forwarded packets with a constant inter-packet gap. Thus, the generation of the multiple packets in the packet train is handled by the packet-processing unit, while the precise inter-packet timing is provided by the traffic-shaping queue in the queuing hardware.

Abstract: Aspects of a high-precision packet train generation process are distributed among several distinct processing elements. In some embodiments a control processor configures a packet-processing unit with a packet train context that includes details such as the number of packets to be generated and the headers to be included in the packets. The packet-processing unit takes a packet to be used in the packet train and recirculates it a number of times, as specified by the packet train context. The recirculated packets, with the appropriate headers inserted, are forwarded to a traffic-shaping queue in queuing hardware. The traffic-shaping queue is configured to output the forwarded packets with a constant inter-packet gap. Thus, the generation of the multiple packets in the packet train is handled by the packet-processing unit, while the precise inter-packet timing is provided by the traffic-shaping queue in the queuing hardware.

Abstract: Apparatus, systems, and methods may operate to receive a request to roll back one or more individually specified software packages to their respective package states at a prior time on a processing system, to determine a series of transactions on the processing system associated with the individually specified software packages and their dependencies, conducted between the current time and the prior time, and to roll back the dependencies and the individually specified software packages to the respective package states on the processing system. Additional apparatus, systems, and methods are disclosed.