Abstract: Some embodiments provide a method for performing data traffic monitoring. The method processes a packet through a packet processing pipeline that includes multiple stages. At a filtering stage, the method tags the packet with a set of monitoring actions for subsequent stages to perform on the packet based on a determination that the packet matches a particular filter. For each stage of a set of packet processing stages subsequent to the filtering stage, the method (i) executes any monitoring actions specified for the stage to perform on the packet and (ii) sends the packet to a next stage in the packet processing pipeline.

Abstract: Some embodiments of the invention provide a method for performing dynamic packet tracing in a network that includes a network controller and multiple host computers, each host computer including a set of packet processing stages for processing packet flows in the network. The method is performed for each packet processing stage in the set of packet processing stages at a particular host computer in the network. The method provides to the packet processing stage a set of trace instructions for use in generating a set of trace data when processing packets belonging to a particular packet flow for which a packet tracing operation has been defined. The method receives from the packet processing stage the set of trace data generated during processing of a packet belonging to the particular packet flow.

Abstract: Some embodiments provide a method of identifying packet latency in a software defined datacenter (SDDC) that includes a network and multiple host computers executing multiple machines. At a first host computer, the method identifies and stores (i) multiple time values associated with several packet processing operations performed on a particular packet sent by a first machine executing on the first host computer, and (ii) a time value associated with packet transmission through the SDDC network from the first host computer to a second host computer that is a destination of the particular packet. The method provides the stored time values to a set of one or more controllers to process to identify multiple latencies experienced by multiple packets processed in the SDDC.

Abstract: Some embodiments provide a method for performing data traffic monitoring. The method processes a packet through a packet processing pipeline that includes multiple stages. At a filtering stage, the method tags the packet with a set of monitoring actions for subsequent stages to perform on the packet based on a determination that the packet matches a particular filter. For each stage of a set of packet processing stages subsequent to the filtering stage, the method (i) executes any monitoring actions specified for the stage to perform on the packet and (ii) sends the packet to a next stage in the packet processing pipeline.

Abstract: Example methods and systems to perform flow cache information update(s) for packet processing are described. In one example, a network element may configure flow cache information specifying a set of actions based on a sequence of stages that is executable during slow-path packet processing. The network element may configure dependency information specifying execution dependence or independence among the set of actions during fast-path packet processing. In response to detecting a configuration change associated with stage(s) from the sequence of stages, the network element may identify first action(s) affected by the configuration change and second action(s) not affected by the configuration change. This way, a granular update may be performed to the flow cache information by updating the at least one first action, but not the at least one second action.

Abstract: Proposed is a two-dimensional nanosheet, which can significantly improve catalytic efficiency by realizing a two-dimensional nanosheet structure with a high specific surface area including a metal material having an amorphous crystal structure as an electrochemical catalyst to fully utilize the characteristics of a metal oxide catalyst material with excellent electrical conductivity and, at the same time, which is easy for mass synthesis in manufacturing method due to its relatively simple manufacturing process, and is easy to realize ultra-thin and large-area.

Abstract: Some embodiments provide a method for performing data traffic monitoring. The method processes a packet through a packet processing pipeline that includes multiple stages. At a filtering stage, the method tags the packet with a set of monitoring actions for subsequent stages to perform on the packet based on a determination that the packet matches a particular filter. For each stage of a set of packet processing stages subsequent to the filtering stage, the method (i) executes any monitoring actions specified for the stage to perform on the packet and (ii) sends the packet to a next stage in the packet processing pipeline.

Abstract: Proposed are an electrochemical catalyst that can replace platinum by being implemented into a two-dimensional metal nanosheet with a high specific surface area to fully use metal catalyst materials and metal phosphide catalyst materials with excellent electrical conductivity, simultaneously having a simple manufacturing process to facilitate mass synthesis to be capable of implementing an ultra-thin film and a large area to maximize the utilization of catalysts, and a manufacturing method thereof.

Abstract: Some embodiments provide a method for performing data traffic monitoring. For each packet processing stage of a set of packet processing stages in a packet processing pipeline, the method determines whether a packet received by the packet processing pipeline specifies a set of monitoring actions to be performed on the packet. When the packet specifies a set of monitoring action, the method determines whether the monitoring actions in the set are supported by the packet processing stage. The method executes the supported monitoring actions on the packet in addition to processing the packet according to configuration data for the stage.

Abstract: Some embodiments provide a method of aggregating and providing packet metrics collected during a live packet monitoring session performed for packets matching a specified set of characteristics. The method receives, from one or more computing devices that process packets during the live packet monitoring session, multiple metrics associated with a set of packets matching the specified set of characteristics. Metrics associated with each packet in the set are accompanied by a packet identifier (ID) used to tag the packet by an initial computing device that processed the packet. The method uses the accompanying packet IDs to aggregate the received plurality of metrics. The method provides (i) an aggregated set of session metrics for the set of packets matching the specified set of characteristics during the live packet monitoring session and (ii) individual packet metrics using the packet IDs for at least one packet in the set of packets.

Abstract: Example methods and systems are provided for simulation-based cross-cloud connectivity checks. One example method may include injecting a connectivity check packet in a first cloud environment, and obtaining first report information associated with a first stage of forwarding the connectivity check packet from one or more first observation points in the first cloud environment. The method may also comprise: based on configuration information associated with one or more second observation points in the second cloud environment, simulating a second stage of forwarding the connectivity check packet towards a second virtualized computing instance via the one or more second observation points. The method may further comprise: generating second report information associated with the simulated second stage to identify a connectivity status between a first virtualized computing instance and the second virtualized computing instance based on the first report information and the second report information.

Abstract: Some embodiments provide a method of aggregating and providing packet metrics collected during a live packet monitoring session performed for packets matching a specified set of characteristics. The method receives, from one or more computing devices that process packets during the live packet monitoring session, multiple metrics associated with a set of packets matching the specified set of characteristics. Metrics associated with each packet in the set are accompanied by a packet identifier (ID) used to tag the packet by an initial computing device that processed the packet. The method uses the accompanying packet IDs to aggregate the received plurality of metrics. The method provides (i) an aggregated set of session metrics for the set of packets matching the specified set of characteristics during the live packet monitoring session and (ii) individual packet metrics using the packet IDs for at least one packet in the set of packets.

Abstract: Some embodiments provide a method for performing data traffic monitoring. The method processes a packet through a packet processing pipeline that includes multiple stages. At a filtering stage, the method tags the packet with a set of monitoring actions for subsequent stages to perform on the packet based on a determination that the packet matches a particular filter. For each stage of a set of packet processing stages subsequent to the filtering stage, the method (i) executes any monitoring actions specified for the stage to perform on the packet and (ii) sends the packet to a next stage in the packet processing pipeline.

Abstract: Some embodiments provide a method for performing data traffic monitoring. For each packet processing stage of a set of packet processing stages in a packet processing pipeline, the method determines whether a packet received by the packet processing pipeline specifies a set of monitoring actions to be performed on the packet. When the packet specifies a set of monitoring action, the method determines whether the monitoring actions in the set are supported by the packet processing stage. The method executes the supported monitoring actions on the packet in addition to processing the packet according to configuration data for the stage.

Abstract: Example methods and systems to perform flow cache information update(s) for packet processing are described. In one example, a network element may configure flow cache information specifying a set of actions based on a sequence of stages that is executable during slow-path packet processing. The network element may configure dependency information specifying execution dependence or independence among the set of actions during fast-path packet processing. In response to detecting a configuration change associated with stage(s) from the sequence of stages, the network element may identify first action(s) affected by the configuration change and second action(s) not affected by the configuration change. This way, a granular update may be performed to the flow cache information by updating the at least one first action, but not the at least one second action.

Abstract: Some embodiments provide a method of identifying packet latency in a software defined datacenter (SDDC) that includes a network and multiple host computers executing multiple machines. At a first host computer, the method identifies and stores (i) multiple time values associated with several packet processing operations performed on a particular packet sent by a first machine executing on the first host computer, and (ii) a time value associated with packet transmission through the SDDC network from the first host computer to a second host computer that is a destination of the particular packet. The method provides the stored time values to a set of one or more controllers to process to identify multiple latencies experienced by multiple packets processed in the SDDC.

Abstract: Example methods and systems for flow-based latency measurement for logical overlay network traffic are described. In one example, in response to detecting a first inner data packet associated with a packet flow, a first computer system may generate and send a first encapsulated packet via a logical overlay tunnel towards a second computer system. The first encapsulated packet may be generated by encapsulating the first inner data packet with a first outer header that includes first time information associated with the first inner data packet at the first computer system. In response to detecting a second encapsulated packet from the second computer system via the logical overlay tunnel, the first computer system may determine a flow-based latency measurement associated with the packet flow based on the first time information, and second time information identified from a second outer header of the second encapsulated packet.

Abstract: Example methods and systems for flow-based latency measurement for logical overlay network traffic are described. In one example, in response to detecting a first inner data packet associated with a packet flow, a first computer system may generate and send a first encapsulated packet via a logical overlay tunnel towards a second computer system. The first encapsulated packet may be generated by encapsulating the first inner data packet with a first outer header that includes first time information associated with the first inner data packet at the first computer system. In response to detecting a second encapsulated packet from the second computer system via the logical overlay tunnel, the first computer system may determine a flow-based latency measurement associated with the packet flow based on the first time information, and second time information identified from a second outer header of the second encapsulated packet.

Abstract: Some embodiments provide a method of identifying packet latency in a software defined datacenter (SDDC) that includes a network and multiple host computers executing multiple machines. At a first host computer, the method identifies and stores (i) multiple time values associated with several packet processing operations performed on a particular packet sent by a first machine executing on the first host computer, and (ii) a time value associated with packet transmission through the SDDC network from the first host computer to a second host computer that is a destination of the particular packet. The method provides the stored time values to a set of one or more controllers to process to identify multiple latencies experienced by multiple packets processed in the SDDC.

Abstract: Some embodiments provide a method of identifying packet latency in a software defined datacenter (SDDC) that includes a network, several host computers executing several machines, and a set of one or more controllers. At the set of controllers, the method o receives, from a set of host computers, (i) a first set of time values associated with multiple packet processing operations performed on packets sent by a set of machines executing on the set of host computers and (ii) a second set of time values associated with packet transmission between host computers through the SDDC network. The method processes the first and second sets of time values to identify a set of latencies experienced by multiple packets processed and transmitted in the SDDC.