146results about How to "Detect failure" patented technology

Some embodiments provide a method for providing a layer 2 (L2) bump-in-the-wire service at a gateway device (e.g., a layer 3 (L3) gateway device) at the edge of a logical network. The method, in some embodiments, establishes a connection from a first interface of the gateway device to a service node that provides the L2 service. The method also establishes a connection from a second interface of the gateway device to the L2 service node. The method then sends data messages received by the gateway device that require the L2 service to the service node using the first interface. Some embodiments provide a method for applying different policies at the service node for different tenants of a datacenter. Data messages received for a particular tenant that require the L2 service are encapsulated or marked as belonging to the tenant before being sent to the service node. Based on the encapsulation or marking, the service node provides the service according to policies defined for the tenant.

Some embodiments provide a method for detecting a failure of a layer 2 (L2) bump-in-the-wire service at a device. In some embodiments, the device sends heartbeat signals to a second device connected to L2 service nodes in order to detect failure of the L2 service (e.g., a failure of all the service nodes). In some embodiments, the heartbeat signals are unidirectional heartbeat signals (e.g., a unidirectional bidirectional-forwarding-detection (BFD) session) sent from each device to the other. The heartbeat signals, in some embodiments, use a broadcast MAC address in order to reach the current active L2 service node in the case of a failover (i.e., an active service node failing and a standby service node becoming the new active service node). The unidirectional heartbeat signals are also used, in some embodiments, to decrease the time between a failover and data messages being forwarded to the new active service node.

In a failure detecting apparatus, acquiring unit acquires a plurality of images captured by a plurality of imaging devices in which exposures thereof are capable of being individually controlled. The plurality of images including an overlapped region that represents a region where images are overlapped. The region extracting unit extracts a plurality of overlapped regions from the plurality of images acquired by the acquiring unit. The feature extracting unit extracts features of image from the plurality of overlapped regions extracted by the region extracting unit. Further, the comparing unit compares the features of image between the plurality of overlapped regions and the similarity determining unit determines whether or not the features of image are similar based on a result of comparing by the comparing unit. The failure determining unit determines a failure in the imaging device when the similarity determining unit determines the features of image are not similar.

The liquid ejection head comprises: a plurality of liquid ejection ports; a plurality of pressure chambers which are respectively communicated with the liquid ejection ports; a diaphragm which configures at least one surface of each of the pressure chambers; and a plurality of piezoelectric elements which are disposed on a surface of the diaphragm opposite from the pressure chamber, and from which at least individual electrodes are separated in an area corresponding to the pressure chamber, wherein liquid is ejected from the liquid ejection port by causing the plurality of piezoelectric elements to make vibration.