Abstract: A relay includes a contact container having a contact chamber, a pair of first through holes and a second through hole communicated with the contact chamber; a pair of static contact leading-out terminals passed through the first through holes and connected to the contact container; a connector passing through the second through hole and connected to the contact container; a first magnetizer provided in the contact chamber and connected to the connector; and a pushing rod assembly including a movable component with a movable contact piece. The movable component is movably provided in the contact chamber to make the movable contact piece come into contact with or separate from the pair of static contact leading-out terminals. The first magnetizer is arranged at a side of the movable contact piece facing the static contact leading-out terminals.

Abstract: The efficiency of segment cleaning for a log-structured file system (LFS) is enhanced at least by storing additional information in a segment usage table (SUT). Live blocks (representing portions of stored objects) in an LFS are determined based at least on the SUT. Chunk identifiers associated with the live blocks are read. The live blocks are coalesced at least by writing at least a portion of the live blocks into at least one new segment. A blind update of at least a portion of the chunk identifiers in a chunk map is performed to indicate the new segment. The blind update includes writing to the chunk map without reading from the chunk map. In some examples, the objects comprise virtual machine disks (VMDKs) and the SUT changes between a list format and a bitmap format, to minimize size.

Abstract: Deleting directories in a virtual distributed file system (VDFS), and non-virtual file systems, involves changing the name of a selected directory to a unique object identifier (UID) and moving the selected directory, named according to the UID, to a deletion target directory. A recursive process, implemented using a background deletion thread, starts in the current directory and identifies objects in the current directory. For an object that is a file or an empty directory, the object is added to a deletion queue. For an object that is a directory that is not empty, the recursion drops down into that directory as the new current directory. When the recursion has exhausted the selected directory, or some maximum object count has been reached, the objects identified in the deletion queue are deleted. This approach can also be used for file operations other than deletion, such as compression, encryption, and hashing.

Abstract: A positive electrode active material is granular and comprises a compound represented by formula 1: (NaxAy)a?bM1[M2(CN)6]?, wherein A is selected from at least one of alkali metal elements and has an ionic radius greater than that of sodium, M1 and M2 are each independently selected from at least one of transition metal elements, 0<y?0.2, 0<x+y?2, 0???1, a+b=2, 0.85?a?0.98, (represents a vacancy, and b represents the number of vacancies; and when the positive electrode active material is dissolved, at a temperature of 20° C., into an aqueous solution having a concentration of 5 g/100 g water, a pH value of the aqueous solution is in a range of 7.6 to 8.5. The positive electrode active material has good cycling and rate performance, and a high specific capacity.

Abstract: A data fusion method and apparatus for a LiDAR system includes a source LiDAR and at least one secondary LiDAR for obtaining a first point cloud data set of the LiDAR system at a first time point and a second point cloud data set of the system at a second time point separately; determining candidate transformation matrix sets based on the first point cloud data set, where each candidate transformation matrix set includes candidate transformation matrices for transforming point cloud data of a corresponding secondary LiDAR into a coordinate system of the source LiDAR; selecting a target transformation matrix from candidate transformation matrices in each of the candidate transformation matrix sets based on the second point cloud data set; and fusing point cloud data of the source LiDAR and point cloud data of the at least one secondary LiDAR based on a target transformation matrix corresponding to each secondary LiDAR.

Abstract: The present application provides a positive electrode active material which may be in a particulate form and comprise a compound represented by Formula 1: NaxAyM1[M2(CN)6]?·zH2O??Formula 1 wherein, A is selected from at least one of an alkali metal element and an alkaline earth metal element, and the ionic radius of A is greater than the ionic radius of sodium; M1 and M2 are each independently selected from at least one of a transition metal element, 0<y?0.2, 0<x+y?2, 0<??1, and 0?z?10; and the particles of the positive electrode active material may have a gradient layer in which the content of the A element decreases from the particle surface to the particle interior.

Abstract: Systems and methods for inspection and repair of VSAN object metadata. A user-space indirection layer is maintained to map logical addresses of VSAN objects to physical memory addresses of their metadata. Commands may then be sent from the user space to distributed object manager (DOM) clients, with the physical addresses of metadata of objects to be inspected. DOM owners thus may bypass their own indirection layers to retrieve object metadata directly from received user commands. Retrieved information is then used to reconstruct and repair object metadata. Repaired metadata may be written back to the VSAN by transmitting a write request containing the physical address at which the repaired metadata is to be written. DOM owners may be placed in a specified mode in which received I/O instructions are ignored unless they are designated as being for metadata repair purposes, such as by including a physical address.

Abstract: Provided are a layered oxide and a preparation method thereof, a positive electrode sheet, a secondary battery, a battery module, a battery pack and an electrical apparatus. The layered oxide includes an oxide with the general formula NaxMnyAaQbCcO2, where A is one or two of Fe and Ni; Q is one or more of transition metal elements containing 3d or 4d orbital electrons except Fe and Ni; C is one or two of Al and B, 0.66<x?1, 0.2?y?0.6, 0.3?a?0.6, 0<b?0.2, 0<c?0.1, and 1?b/c?100. The A element undergoes valence changes to provide charge compensation in a charge and discharge process, thereby improving the specific capacity of the layered oxide; the Q element and oxygen form a hybrid orbital, inhibiting irreversible oxygen losses and structure collapse of oxygen under a high voltage; the C element has a high ionic potential so as to effectively inhibit oxygen losses; and 1?b/c?100.

Abstract: A method for efficient journal truncation is provided. A method for journal truncation includes maintaining a journal in a memory of a computing system including a plurality of records. Each record indicates a transaction in an ordered data structure. The method includes maintaining a truncation queue in the memory including one or more entries. Each entry in the truncation queue includes a physical on-disk offset associated with a different record of the plurality of records. The method includes determining to truncate the journal and truncating records, of the plurality of records, from the journal starting from a beginning record in the journal up to the record with the physical on-disk offset associated a least recent entry of the one or more entries in the truncation queue, where the truncating includes removing the records from the memory.

Abstract: A method for efficient write-back for journal truncation is provided. A method includes maintaining a journal in a memory of a computing system including a plurality of records. Each record indicates a transaction associated with one or more pages in an ordered data structure and maintaining a dirty list including an entry for each page indicated by a record in the journal. Each entry in the dirty list includes a respective first log sequence number (LSN) associated with a least recent record of the plurality of records that indicates the page and a respective second LSN associated with a most recent record of the plurality of records that indicates the page. The method includes determining to truncate the journal. The method includes identifying one or more records, of the plurality of records, from the journal to write back to a disk, where the identifying is based on the dirty list.

Abstract: The disclosure describes growing a data cache using a background hash bucket growth process. A first memory portion is allocated to the data buffer of the data cache and a second memory portion is allocated to the metadata buffer of the data cache based on the cache growth instruction. The quantity of hash buckets in the hash bucket buffer is increased and the background hash bucket growth process is initiated, wherein the process is configured to rehash hash bucket entries of the hash bucket buffer in the increased quantity of hash buckets. A data entry is stored in the data buffer using the allocated first memory portion of the data cache and metadata associated with the data entry is stored using the allocated second memory portion of the metadata buffer, wherein a hash bucket entry associated with the data entry is stored in the increased quantity of hash buckets.

Abstract: Examples disclosed herein relate to propagating changes made on a file system volume of a primary cluster of nodes to the same file system volume also being managed by a secondary cluster of nodes. An application is executed on both clusters, and data changes on the primary cluster are mirrored to the secondary cluster using an exo-clone file. The exo-clone file includes the differences between two or more snapshots of the volume on the primary cluster, along with identifiers of the change blocks and (optionally) state information thereof. Just these changes, identifiers, and state information are packaged in the exo-clone file and then exported to the secondary cluster, which in turn makes the changes to its version of the volume. Exporting just the changes to the data blocks and the corresponding block identifiers drastically reduces the information needed to be exchanged and processed to keep the two volumes consistent.

Abstract: An example method of upgrading a distributed storage object from a first version to a second version includes: querying metadata of a first component configured according to the first version of the distributed storage object, the metadata defining extents of data on a disk group of the first component; populating, for a second component configured according to the second version of the distributed storage object, logical and middle maps based on the metadata such that initial entries in the logical map point to initial entries in the middle map, and the initial entries in the middle map point to physical addresses of the disk group of the first component; and reading the data from the disk group of the first component and writing the data to a disk group of the second component while updating the initial entries in the middle map.

Abstract: The location of resources for file services are located within the same site, thereby eliminating or reducing performance issues caused by cross-site accesses in a stretched cluster environment. A file server placement algorithm initially places file servers at a site based at least in part on host workload and affinity settings, and can perform failover to move the file servers to a different location (e.g., to a different host on the same site or to another site) in the event of a failure of the host where the file servers were initially placed. File servers may be co-located with clients at a location based on client latencies and site workload. Failover support is also provided in the event that the sites in the stretched cluster have different subnet addresses.

Abstract: A method for reverse range lookup in an ordered data structure of keys, wherein each key comprises a logical block address (LBA) and a snapshot identifier (ID) of one of one or more snapshots in a snapshot hierarchy, is provided. The keys in the ordered data structure are in an order from smallest to largest LBA, wherein in the order, keys having a same LBA are ordered from smallest to largest snapshot ID. The method includes determining a range of LBAs and traversing the ordered data structure in reverse order until a key is found that: has an LBA and a snapshot ID that is less than or equal to the last LBA and the largest snapshot ID, respectively. The method further includes adding an extent corresponding to the located key to an extent result list if the snapshot ID of the located key is not within a deny list.

Abstract: A method for resumeable snapshot deletion is provided. A method for deletion of nodes maintained in an ordered data structure for a first snapshot includes processing the nodes maintained in the ordered data structure according to a defined order, setting a node path cursor with a pointer to a node and an indication of the deletion of the node; storing the node path cursor in a persistent storage; and during processing of the nodes: detecting a failure; after the failure, checking the pointer of the node path cursor; and resuming processing of the nodes starting from the first node indicated by the pointer.

Abstract: The present disclosure relates to bootstrapping an encrypted single node VSAN cluster. One method includes receiving a request to create an encrypted VSAN cluster from a single host in a software-defined datacenter, deploying a virtual server on a VSAN datastore of the software-defined datacenter, registering a native key provider (NKP) in the virtual server, creating an empty VSAN cluster encrypted by the NKP, adding the single host to the encrypted empty cluster to create a one-host encrypted cluster, registering a KMIP KMS in the virtual server, switching encryption of the one-host encrypted cluster from the NKP to the KMIP KMS, and adding another host to the one-host encrypted cluster to create the encrypted cluster.

Abstract: Techniques for efficiently exporting snapshot changes are provided. In some embodiments, a system may receive a first snapshot of a data set in a storage system and a second snapshot the data set in the storage system. The system may further generate actions based on differences between the first snapshot and the second snapshot to produce a list of actions, wherein a modification to a file or directory path having a first directory location includes a first action to rename a file from the first directory location to a temporary storage location and a second action to rename the file from the temporary storage location to a second directory location; and provide the generated actions to a backup system. The backup system may apply the generated actions to a first backup associated with the first snapshot to produce a second backup associated with the second snapshot.

Abstract: System and method for managing distributed storage objects for host unavailability in a distributed storage system uses at least one of a crash indicator in a specific on-disk block and a paused object indicator for a distributed storage object to determine whether to perform data recovery for the distributed storage object. When the crash indicator is set or the paused object indicator implies that the distributed storage object is a paused object, the distributed storage object is left as a paused object without perform the data recovery for the distributed storage object. When the crash indicator is unset and the paused object indicator implies that the distributed storage object is not a paused object, the data recovery for the distributed storage object is performed.

Abstract: Techniques for efficiently managing a file clone from a filesystem which supports efficient volume snapshots are provided. In some embodiments, a system may receive an instruction to remove the file clone from the filesystem. The file clone may be a point-in-time copy of metadata of an original file. The system may further—for a file map entry in a filesystem tree associated with the file clone, the file map entry indicating a data block—decrement a reference count in a reference count entry associated with the file map entry. The reference count entry may be stored in the filesystem tree according to a key and the key may comprise an identification of the original file. The system may further reclaim the data block in a storage system when the reference count is zero.