Abstract: The disclosure is directed to an iron-nitride material having a polycrystalline microstructure including a plurality of elongated crystallographic grains with grain boundaries, the iron-nitride material including at least one of an ??-Fe16N2 phase and a body-center-tetragonal (bct) phase comprising Fe and N. The disclosure is also directed a method producing an iron-nitride material.

Abstract: An approach is provided in which the approach receives an image that includes multiple image points and constructs a plane in the image based on a first subset of the plurality of image points. The approach identifies a second subset of the image points that belong to the plane and are not part of the first subset of image points, and removes the first subset of image points and the second subset of image points form the image points. The approach annotates the remaining subset of image points in the image.

Abstract: Data replication groups may be used to store data in a distributed computing environment. The data replication groups may include a set of nodes executing a consensus protocol to maintain data durably. The nodes of the data replication groups may generate logs containing information corresponding committed operations performed by the nodes. These logs may be collected and processed to obtain useful information corresponding to the operation of the data replication group. Furthermore, this processed information may be provided in the form of a stream to enable event driven operations corresponding to the logs.

Abstract: A block-based storage system hosts logical volumes that are implemented via multiple replicas of volume data stored on multiple resource hosts in different failure domains. Also, the block-based storage service allows multiple client computing devices to attach to a same given logical volume at the same time. In order to prevent unnecessary failovers, a primary node storing a primary replica is configured with a health check application programmatic interface (API) and a secondary node storing a secondary replica determines whether or not to initiate a failover based on the health of the primary replica.

Abstract: A method for preparing a modular planar interconnect plate includes steps of a) providing a metal blank sheet having a main region and two first lateral regions, b) forming two openings respectively in the first lateral regions, and c) stamping to form protrusions and depressions at the main region on lower and upper surfaces of the metal blank sheet. In the stamping step, each of two lower surrounding protrusions and two upper surrounding depressions is formed to surround a corresponding one of the openings, and each of an upper surrounding protrusion and a lower surrounding depression is formed to surround the first lateral regions and the corresponding ones of the protrusions and depressions formed at the main region.

Abstract: A block-based storage system hosts logical volumes that are implemented via multiple replicas of volume data stored on multiple resource hosts in different failure domains. Also, the block-based storage service allows multiple client computing devices to attach to a same given logical volume at the same time. In order to prevent unnecessary failovers, a primary node storing a primary replica is configured with a health check application programmatic interface (API) and a secondary node storing a secondary replica determines whether or not to initiate a failover based on the health of the primary replica.

Abstract: A method for preparing a modular planar interconnect plate includes steps of a) providing a metal blank sheet having a main region and two first lateral regions, b) forming two openings respectively in the first lateral regions, and c) stamping to form protrusions and depressions at the main region on lower and upper surfaces of the metal blank sheet. In the stamping step, each of two lower surrounding protrusions and two upper surrounding depressions is formed to surround a corresponding one of the openings, and each of an upper surrounding protrusion and a lower surrounding depression is formed to surround the corresponding ones of the protrusions and depressions formed at the main region and the first lateral regions.

Abstract: Systems and methods are provided to manage replicas of a virtualized block storage volume. The master replica of the virtualized block storage volume can heartbeat with each secondary replica of the virtualized block storage volume to provide an indication of the status of the master replica. Each secondary replica can reply to the heartbeat of the master replica. Each replica can be configured to request an updated replica configuration based on not receiving a heartbeat from one of the replicas. The master replica can request an updated replica configuration after a first time period without receiving a reply from one of the secondary replicas and each secondary replica can request an updated replica configuration after a second time period without receiving a communication from the master replica. Use of the heartbeat process between the master replica and the secondary replicas can increase system speed or reduce power consumption.

Abstract: A method for preparing a modular planar interconnect plate for a solid oxide fuel cell includes the steps of: (a) providing a metal blank sheet, (b) stamping a main region of the metal blank sheet to form a plurality of columns of upper protrusions on an upper surface of the main region of the metal blank sheet and a plurality of columns of lower depressions on a lower surface of the main region of the metal blank sheet, and (c) stamping the main region of the metal blank sheet to form a plurality of rows of lower protrusions on a lower surface of the main region of the metal blank sheet and a plurality of rows of upper depressions on the upper surface of the main region of the metal blank sheet.

Abstract: A method for preparing a modular planar interconnect plate for a solid oxide fuel cell includes the steps of: (a) providing a metal blank sheet, (b) stamping a main region of the metal blank sheet to form a plurality of columns of upper protrusions on an upper surface of the main region of the metal blank sheet and a plurality of columns of lower depressions on a lower surface of the main region of the metal blank sheet, and (c) stamping the main region of the metal blank sheet to form a plurality of rows of lower protrusions on a lower surface of the main region of the metal blank sheet and a plurality of rows of upper depressions on the upper surface of the main region of the metal blank sheet.

Abstract: A system that hosts computing resources may implement optimistically granting permission to host computing resources. A request for permission to host a computing resource may be received by a control plane. If the control plane determines that the resource host is the first to request permission to host the resource, then the control plane may store an indication of permission that blocks other resource hosts from obtaining permission to host the computing resource and sending an acknowledgement of permission to the resource host that requested permission.

Abstract: A block-based storage system hosts logical volumes that are implemented via multiple replicas of volume data stored on multiple resource hosts in different failure domains. Also, the block-based storage service allows multiple client computing devices to attach to a same given logical volume at the same time. In order to prevent unnecessary failovers, a primary node storing a primary replica is configured with a health check application programmatic interface (API) and a secondary node storing a secondary replica determines whether or not to initiate a failover based on the health of the primary replica.

Abstract: A method for preparing a modular planar interconnect plate for a solid oxide fuel cell includes the steps of: (a) providing a metal blank sheet, (b) stamping a main region of the metal blank sheet to form a plurality of columns of upper protrusions on an upper surface of the main region of the metal blank sheet and a plurality of columns of lower depressions on a lower surface of the main region of the metal blank sheet, and (c) stamping the main region of the metal blank sheet to forma plurality of rows of lower protrusions on a lower surface of the main region of the metal blank sheet and a plurality of rows of upper depressions on the upper surface of the main region of the metal blank sheet.

Abstract: A block-based storage system hosts logical volumes that are implemented via multiple replicas of volume data stored on multiple resource hosts in different failure domains. Also, the block-based storage service allows multiple client computing devices to attach to a same given logical volume at the same time. In order to prevent unnecessary failovers, a primary node storing a primary replica is configured with a health check application programmatic interface (API) and a secondary node storing a secondary replica determines whether or not to initiate a failover based on the health of the primary replica.

Abstract: A block-based storage system hosts logical volumes that are implemented via multiple replicas of volume data stored on multiple resource hosts in different failure domains. Also, the block-based storage service allows multiple client computing devices to attach to a same given logical volume at the same time. A membership group authority authorizes sequence numbers for a given logical volume and an associated membership group. The members of the membership group ensure that the members are in agreement on the latest sequence number for the given logical volume before responding to read or write requests directed to the given logical volume.

Abstract: A method for preparing a modular planar interconnect plate for a solid oxide fuel cell includes the steps of: (a) providing a metal blank sheet, (b) stamping a main region of the metal blank sheet to form a plurality of columns of upper protrusions on an upper surface of the main region of the metal blank sheet and a plurality of columns of lower depressions on a lower surface of the main region of the metal blank sheet, and (c) stamping the main region of the metal blank sheet to forma plurality of rows of lower protrusions on a lower surface of the main region of the metal blank sheet and a plurality of rows of upper depressions on the upper surface of the main region of the metal blank sheet.

Abstract: Data replication groups may be used to store data in a distributed computing environment. The data replication groups may include a set of nodes executing a consensus protocol to maintain data durably. In order to increase the speed of provisioning, a data replication may be provision with less than the total number of nodes to be included in the group. Once an initial set of nodes have been provisioned and are implementing a consensus protocol, the data replication group may begin to receive traffic. Furthermore, new nodes may be added to the group until the total number of nodes for the group has been reached.

Abstract: Data replication groups may be used to store data in a distributed computing environment. The data replication groups may include a set of nodes executing a consensus protocol to maintain data durably. During the execution of the set of nodes various nodes may become stale or otherwise obtain a state that is inconsistent with at least one other node of the data replication group. A catch up algorithm may be employed in which a set of teachers is initialized, the various node which may be stale may select a teacher from the set of teachers and perform learning operations. This process may be repeated until the state of the various nodes is current with at least one other node of the data replication group.

Abstract: Data replication groups may be used to store data in a distributed computing environment. A data replication group may include a set of nodes executing a consensus protocol to maintain data durably. In order to increase efficiency and performance of the data replication, a particular node of the data replication group may be assigned the role of master node. The role of master node may be lease in accordance with a consensus protocol. If the lease is not renewed within an interval of time election/selection of a new master node may be commenced.

Abstract: Data replication groups may be used to store data in a distributed computing environment. The data replication groups may include a set of nodes executing a consensus protocol to maintain data durably. In order to monitor and debug the operation of the data replication group a chaining mechanism may be utilized during log creation by the set of nodes of the data replication group. The chaining mechanism may cause entries in the log to indicate an operation being performed and an operation performed immediately prior to the operation being performed. In various embodiments, an outside observer receives the logs and checks the logs for errors indicated by the chaining mechanism.