Abstract: A computer-implemented method, according to one approach, includes: receiving a request to create a new node in a clustered filesystem. In response to receiving the request, a copy of details is retrieved, the copy of details being associated with an established singleton cluster preconfigured to access the clustered filesystem. The retrieved copy of details are further applied to a new node in the clustered filesystem. Moreover, data structures of the new node are modified according to the received request. Other systems, methods, and computer program products are described in additional approaches herein.

Abstract: Computer technology for use with a computer data storage system including a plurality of client computers and a plurality of collector nodes. A file consists of data blocks with each block resides on one of the persistent storage device. Data received at client computers are buffered and then transferred to selected collector nodes depending on which data blocks the data belong to. Location-aware collector node selection is performed by selecting collector nodes, from the plurality of collector nodes, by querying a file system allocation subsystem to determine selected collector nodes for the given data block that owns a persistent storage device on which the given block is allocated. Data for each data block is then sent to and stored in its selected collector nodes.

Abstract: Computer technology for use with a computer data storage system including a plurality of client computers and a plurality of collector nodes. A file consists of data blocks with each block resides on one of the persistent storage device. Data received at client computers are buffered and then transferred to selected collector nodes depending on which data blocks the data belong to. Location-aware collector node selection is performed by selecting collector nodes, from the plurality of collector nodes, by querying a file system allocation subsystem to determine selected collector nodes for the given data block that owns a persistent storage device on which the given block is allocated. Data for each data block is then sent to and stored in its selected collector nodes.

Abstract: Methods that utilize a shadow map to identify bad free bits and duplicate references in a file system are disclosed herein. One method includes a processor generating a shadow map of a file system and utilizing the shadow map to identify bad free bits in a block allocation map of the file system and/or utilizing the shadow map to identify duplicate references in the file system. Also disclosed herein are apparatus, systems, and computer program products that can include, perform, and/or implement the methods for utilizing a shadow map to identify bad free bits and/or duplicate references in a file system.

Abstract: Provided are a computer program product, integrated cache manager, and method for maintaining data in a first level memory and buckets representing regions of memory devices to extend data cache. A plurality of buckets represent distinct regions of memory devices. The buckets are associated with different threshold access count ranges. Data having an access count is stored in one of the buckets associated with a threshold access count range including the access count of the data to store. Data evicted from a first level memory is copied to an initial bucket comprising one of the buckets. Data is moved from a source bucket comprising one of the buckets, including the initial bucket, to a target bucket of the buckets having a target threshold access count range including an access count of the data to move.

Abstract: Provided are a computer program product, system, and method for switching serialization techniques for handling concurrent write requests to a shared file. A first node serializes write requests from client nodes to write to the shared file. The first node determines whether to switch to a second node to manage write quests to the shared file based on a pattern of write requests to the shared file. The client nodes are notified to direct write requests to the shared file to the second node in response to determining to switch to the second node. The second node processes write requests to the shared file to serialize writes to the shared file after the client nodes are notified to submit the write requests to the shared file to the second node.

Abstract: A method for executing operation requests includes formatting one or more storage devices and selecting one or more labeled replicas and one or more distinguished replicas, receiving an operation request with respect to a set of data blocks, identifying a preferred replica corresponding to the received operation request, determining whether the replication-pending bits for the preferred replica are set, and executing the received operation request with respect to the corresponding distinguished replica. A method for executing a write operation request additionally includes setting replication-pending bits with respect to the labeled replica, wherein the replication-pending bits indicate an incomplete write request, writing data to both a labeled replica and a distinguished replica, and clearing the replication-pending bits with respect to the labeled replica to indicate the completion of the write operation.

Abstract: A method and a computer system for asymmetric replication of data are provided. Storage of a set of data is organized as a first copy and as a second copy in non-volatile storage. The second copy is reliable and stored so as to be readable at a speed slower than for the first copy. A read instruction regarding the set of data is received and performed preferentially via the first copy such that the asymmetric replication achieves enhanced performance speed. A request to execute a write operation is received. The write operation is executed to the first copy and to the second copy. In response to determining that the write operation to the first copy was unsuccessful, a label for the first copy is set as stale.

Abstract: A method and a computer system for asymmetric replication of data are provided. Storage of a set of data is organized as a first copy and as a second copy in non-volatile storage. The second copy is reliable and stored so as to be readable at a speed slower than for the first copy. A read instruction regarding the set of data is received and performed preferentially via the first copy such that the asymmetric replication achieves enhanced performance speed. A request to execute a write operation is received. The write operation is executed to the first copy and to the second copy. In response to determining that the write operation to the first copy was unsuccessful, a label for the first copy is set as stale.

Abstract: A computer-implemented method includes monitoring file access activity and generating an audit log based on the file access activity. The method also includes collecting samples of file usage activity, running a pattern recognition algorithm on the samples of the file usage activity for detecting malware activity, and, in response to detecting malware activity, restoring at least one file based on the audit log. A computer program product includes one or more computer readable storage media and program instructions collectively stored on the one or more computer readable storage media. The program instructions include program instructions to perform the foregoing method. A system includes a processor and logic integrated with the processor, executable by the processor, or integrated with and executable by the processor. The logic is configured to perform the foregoing method.

Abstract: Embodiments include a method for fault tolerance in the delivery of event information within a file system cluster. One or more processors to determine event information associated with file system activity performed by a node of the cluster. The one or more processors add the event information to an event log buffer in memory. The one or more processors receive a first log sequence number (LSN) associated with flushing of recovery information from a recovery log buffer. The one or more processors determine the event information in the event log buffer having a log sequence number less than or equal to the first log sequence number, and determining the event information includes log sequence numbers less than or equal to the first log sequence number, the one or more processors flush the corresponding event information from the event log buffer to disk storage.

Abstract: Provided are a computer program product, system, and method for switching serialization techniques for handling concurrent write requests to a shared file. A first node serializes write requests from client nodes to write to the shared file. The first node determines whether to switch to a second node to manage write quests to the shared file based on a pattern of write requests to the shared file. The client nodes are notified to direct write requests to the shared file to the second node in response to determining to switch to the second node. The second node processes write requests to the shared file to serialize writes to the shared file after the client nodes are notified to submit the write requests to the shared file to the second node.

Abstract: Provided are a computer program product, integrated cache manager, and method for maintaining data in a first level memory and buckets representing regions of memory devices to extend data cache. A plurality of buckets represent distinct regions of memory devices. The buckets are associated with different threshold access count ranges. Data having an access count is stored in one of the buckets associated with a threshold access count range including the access count of the data to store. Data evicted from a first level memory is copied to an initial bucket comprising one of the buckets. Data is moved from a source bucket comprising one of the buckets, including the initial bucket, to a target bucket of the buckets having a target threshold access count range including an access count of the data to move.

Abstract: A computer-implemented method includes using a cache replacement algorithm to forcefully evict target data from a cache. Using the cache replacement algorithm includes selectively accessing data in the cache. A computer program product includes one or more computer readable storage media and program instructions collectively stored on the one or more computer readable storage media. The program instructions include program instructions to perform the foregoing method. A system includes a processor and logic integrated with the processor, executable by the processor, or integrated with and executable by the processor. The logic is configured to perform the foregoing method.

Abstract: A method for executing operation requests includes formatting one or more storage devices and selecting one or more labeled replicas and one or more distinguished replicas, receiving an operation request with respect to a set of data blocks, identifying a preferred replica corresponding to the received operation request, determining whether the replication-pending bits for the preferred replica are set, and executing the received operation request with respect to the corresponding distinguished replica. A method for executing a write operation request additionally includes setting replication-pending bits with respect to the labeled replica, wherein the replication-pending bits indicate an incomplete write request, writing data to both a labeled replica and a distinguished replica, and clearing the replication-pending bits with respect to the labeled replica to indicate the completion of the write operation.

Abstract: Embodiments include a method for fault tolerance in the delivery of event information within a file system cluster. One or more processors to determine event information associated with file system activity performed by a node of the cluster. The one or more processors add the event information to an event log buffer in memory. The one or more processors receive a first log sequence number (LSN) associated with flushing of recovery information from a recovery log buffer. The one or more processors determine the event information in the event log buffer having a log sequence number less than or equal to the first log sequence number, and determining the event information includes log sequence numbers less than or equal to the first log sequence number, the one or more processors flush the corresponding event information from the event log buffer to disk storage.

Abstract: A computer-implemented method includes using a cache replacement algorithm to forcefully evict target data from a cache. Using the cache replacement algorithm includes selectively accessing data in the cache. A computer program product includes one or more computer readable storage media and program instructions collectively stored on the one or more computer readable storage media. The program instructions include program instructions to perform the foregoing method. A system includes a processor and logic integrated with the processor, executable by the processor, or integrated with and executable by the processor. The logic is configured to perform the foregoing method.

Abstract: A computer-implemented method includes monitoring file access activity and generating an audit log based on the file access activity. The method also includes collecting samples of file usage activity, running a pattern recognition algorithm on the samples of the file usage activity for detecting malware activity, and, in response to detecting malware activity, restoring at least one file based on the audit log. A computer program product includes one or more computer readable storage media and program instructions collectively stored on the one or more computer readable storage media. The program instructions include program instructions to perform the foregoing method. A system includes a processor and logic integrated with the processor, executable by the processor, or integrated with and executable by the processor. The logic is configured to perform the foregoing method.

Abstract: A composite insulator comprises a rod with an insulating jacket and ribs and at least one end fitting and at least one corona shield. The latter is integrally manufactured from plastic material. It is configured to be coaxially disposed on the composite insulator at the transition from the rod to the end fitting. The corona shield forms a cavity, which is open towards the inside and which can be filled with sealant compound through at least one filling channel and which comprises a closing cuff in axial direction on both sides for sealing the cavity. The diameter of the rod side closing cuff is adapted to the diameter of the insulating jacket, and the diameter of the fitting side closing cuff is adapted to the diameter of the end fitting. The filling channel leads to the cavity from the outside.

Abstract: A composite insulator comprises a rod with an insulating jacket and ribs and at least one end fitting and at least one corona shield. The latter is integrally manufactured from plastic material. It is configured to be coaxially disposed on the composite insulator at the transition from the rod to the end fitting. The corona shield forms a cavity, which is open towards the inside and which can be filled with sealant compound through at least one filling channel and which comprises a closing cuff in axial direction on both sides for sealing the cavity. The diameter of the rod side closing cuff is adapted to the diameter of the insulating jacket, and the diameter of the fitting side closing cuff is adapted to the diameter of the end fitting. The filling channel leads to the cavity from the outside.