Abstract: A locking system for use with a retractable driveshaft includes a housing, a rotating locking ring located at least partially to the housing, and a band configured to cooperatively engage the rotatable locking ring. Applying an axial force to the locking ring with the driveshaft causes rotation of the locking ring, thereby locking the driveshaft with the housing. Applying a second axial force to the locking ring with the driveshaft causes further rotation of the locking ring, which allows withdrawal of the driveshaft from the housing.

Abstract: Methods, systems, and computer-readable media for program code allocation based on processor features are disclosed. Analysis of program code is performed using static analysis and/or runtime analysis. The analysis determines one or more processor features invoked by the program code. One or more program execution servers are selected from a plurality of program execution servers based at least in part on the one or more processor features invoked by the program code. One or more selected program execution servers comprise the one or more processor features invoked by the program code, and an additional one or more of the program execution servers lack the one or more processor features invoked by the program code. The program code is executed using the one or more selected program execution servers.

Abstract: One or more configuration parameters for an object gateway instance are received at an interface to a provider network, the parameters including an identifier of a first object store of the provider network for which to cache objects in a first object cache of the object gateway instance and an indication of a data transfer mode that controls when objects written to the first object cache are written to the first object store. The one or more configuration parameters are stored in a data store of the provider network and sent to the object gateway instance. A read request that includes the identifier of the first object store and a first object identifier is received from the object gateway instance, and a first object associated with the first object identifier and stored in the first object store is sent to the object gateway instance.

Abstract: Aspects relate to a framework for utilizing a single API request to manage the creation of consistent snapshots for a set of volumes attached an individual instance in a distributed computing environment. Responsive to receipt of an API request identifying the instance, the multi-volume snapshot service identifies a set of volumes attached to the identified instance. The identified set of volumes can be processed or filtered to eliminate specific volumes or types of volumes, such as boot volumes. In the event that any snapshot creation attempt fails, the multi-volume snapshot service fails the API request and can delete any snapshot data generated prior to the failure.

Abstract: An exemplary liquid tank level measurement system includes a tank having a wall, an accelerometer attached to the wall and configured to measure a vibration in the wall, and an instrument electronically connected to the accelerometer, the instrument configured to communicate a liquid level condition responsive to a vibration measurement received from the accelerometer.

Abstract: Generally described, one or more aspects of the present application correspond to techniques for automatic recovery from dual isolation in which both the primary and secondary replicas of a volume are stored on isolating servers. The disclosed techniques use handshakes between the client and the replicas to determine which has a better health score. The replica with the better health score becomes the primary replica, and confirms that it and the secondary replica are both in an isolating state. In response, the primary replica seeks a solo blessing, undoes the isolating state at the volume level (the server host will still be in isolating state), and continues handling I/O and peer replication until its healthy peer is complete. These techniques can avoid availability drops when the servers hosting the primary and secondary replicas of a volume enter the isolating state at around the same time.

Abstract: An exemplary passive oil system includes a reservoir housing configured in operation to rotate around a rotational axis, the reservoir housing defining a reservoir between a top wall, a bottom wall, innermost side, and an outer sidewall; and an outlet positioned adjacent the outer sidewall to discharge a lubrication fluid contained in the reservoir in response to the reservoir housing rotating around the rotational axis.

Abstract: A first request to launch a first virtual machine to host a block storage server application is received. At least a portion of a storage capacity of one or more storage devices of a host computer system is provisioned to the first virtual machine as a provisioned storage device. The block storage server application is executed with the first virtual machine. As part of executing the block storage server application, a logical volume is created on the provisioned storage device in response to a second request from a block storage service of a provider network to create the logical volume, a third request to perform an input/output operation is received and performed with the logical volume.

Abstract: A first block storage server virtual machine to host a first volume using one or more storage devices of a computer system is executed by the computer system. A second virtual machine having access to a virtual block storage device is executed by the computer system. A block storage client is executed by the computer system. A first block storage operation is received by the block storage client from the second virtual machine, the first block storage operation to perform on the virtual block storage device. A message is sent by the block storage client to the first block storage server virtual machine to cause the first block storage server virtual machine to perform the block storage operation with the first volume.

Abstract: A first request to create a first storage volume to store a first portion of a first logical volume is received by a first block storage server instance. A second request to create a second storage volume to store a second portion of the first logical volume is received by a second block storage server instance. A third request is sent to a third block storage server instance to create a third storage volume to store the second portion of the first logical volume. The second portion of the first logical volume is stored by the third block storage server instance to the third storage volume. A data store containing an identification of each block storage server instance hosting a portion of the first logical volume is updated to remove an identification of the second block storage server instance and add an identification of the third block storage server instance.

Abstract: A multimode clutch assembly is positioned in a powertrain of a rotorcraft. The clutch assembly includes a freewheeling unit having a driving mode in which torque applied to the input race is transferred to the output race and an overrunning mode in which torque applied to the output race is not transferred to the input race. A bypass assembly has an engaged position that couples the input and output races of the freewheeling unit. An actuator assembly shifts the bypass assembly between engaged and disengaged positions. An engagement status sensor is configured to determine the engagement status of the bypass assembly. In the disengaged position, the overrunning mode of the freewheeling unit is enabled such that the clutch assembly is configured for unidirectional torque transfer. In the engaged position, the overrunning mode of the freewheeling unit is disabled such that the clutch assembly is configured for bidirectional torque transfer.

Abstract: A failsafe multimode clutch assembly is positioned in a powertrain of a rotorcraft. The clutch assembly includes a freewheeling unit having input and output races. The freewheeling unit has a driving mode in which torque applied to the input race is transferred to the output race and an overrunning mode in which torque applied to the output race is not transferred to the input race. A bypass assembly has an engaged position that couples the input and output races of the freewheeling unit. An actuator assembly must be energized to shift the bypass assembly from the engaged position to a disengaged position. In the disengaged position, the overrunning mode of the freewheeling unit is enabled such that the clutch assembly is configured for unidirectional torque transfer. In the engaged position, the overrunning mode of the freewheeling unit is disabled such that the clutch assembly is configured for bidirectional torque transfer.

Abstract: A failsafe multimode clutch assembly is positioned in a powertrain of a rotorcraft. The clutch assembly includes a freewheeling unit having input and output races. The freewheeling unit has a driving mode in which torque applied to the input race is transferred to the output race and an overrunning mode in which torque applied to the output race is not transferred to the input race. A bypass assembly has an engaged position that couples the input and output races of the freewheeling unit. An actuator assembly must be energized to shift the bypass assembly from the engaged position to a disengaged position. In the disengaged position, the overrunning mode of the freewheeling unit is enabled such that the clutch assembly is configured for unidirectional torque transfer. In the engaged position, the overrunning mode of the freewheeling unit is disabled such that the clutch assembly is configured for bidirectional torque transfer.

Abstract: Notice of migration of a portion of a data volume from a first location to a second location is received by a first computer system from a second computer system, where the data volume is separated over a network from the first computer system. A third computer system, separated over a network from the first computer system, is caused to invalidate a mapping between the portion and the first location. An indication that the third computer system seeks access to the portion is identified. A third computer system is enabled, by providing a mapping between the portion and the second location, to access portion at the second location.

Abstract: Generally described, one or more aspects of the present application correspond to techniques for creating multiple encrypted block store volumes of data from an unencrypted source. These encryption techniques can use a transform fleet as an intermediary use between the unencrypted source and the encrypted volumes. The transform fleet can obtain data of the volume from one or both of two sources—an object storage “snapshot” a block storage “source volume”—and can then apply the appropriate encryption key for performing the encryption of a particular volume.

Abstract: Server computers often include one or more input/output (I/O) devices for communicating with a network or directly attached storage device. The data transfer latency for request can be reduced by utilizing ingress data placement logic to bypass the processor of the I/O device. For example, host memory descriptors can be stored in a memory of the I/O device to facilitate placement of the requested data.

Abstract: An exemplary tiltrotor aircraft with a hybrid drive system includes a first propulsion system having a first engine and a first supplemental driver operably coupled to a first proprotor that is operable between a helicopter mode and an airplane mode and a second propulsion system having a second engine and a second supplemental driver operably coupled to a second proprotor that is operable between a helicopter mode and an airplane mode.

Abstract: A first request to launch a first virtual machine to host a block storage server application is received. At least a portion of a storage capacity of one or more storage devices of a host computer system is provisioned to the first virtual machine as a provisioned storage device. The block storage server application is executed with the first virtual machine. As part of executing the block storage server application, a logical volume is created on the provisioned storage device in response to a second request from a block storage service of a provider network to create the logical volume, a third request to perform an input/output operation is received and performed with the logical volume.

Abstract: A first request to create a first storage volume to store a first portion of a first logical volume is received by a first block storage server instance. A second request to create a second storage volume to store a second portion of the first logical volume is received by a second block storage server instance. A third request is sent to a third block storage server instance to create a third storage volume to store the second portion of the first logical volume. The second portion of the first logical volume is stored by the third block storage server instance to the third storage volume. A data store containing an identification of each block storage server instance hosting a portion of the first logical volume is updated to remove an identification of the second block storage server instance and add an identification of the third block storage server instance.

Abstract: A first block storage server virtual machine to host a first volume using one or more storage devices of a computer system is executed by the computer system. A second virtual machine having access to a virtual block storage device is executed by the computer system. A block storage client is executed by the computer system. A first block storage operation is received by the block storage client from the second virtual machine, the first block storage operation to perform on the virtual block storage device. A message is sent by the block storage client to the first block storage server virtual machine to cause the first block storage server virtual machine to perform the block storage operation with the first volume.