Abstract: Asynchronous messages are used to prefetch and/or relinquish tokens used in providing locking of shared resources. A message is sent to prefetch one or more tokens, and prior to receiving a reply for the message, another message (e.g., an acquire) is sent for at least one of those tokens. Similarly, a message is sent indicating a voluntary relinquish of one or more tokens and without having acknowledgment that the relinquish request was processed, a further message (e.g., an acquire) is sent for at least one of the tokens. Multiple tokens may be acquired and/or relinquished in a single message to the token server. This reduces message delays and overall message traffic.

Abstract: The invention relates to a jack bracket (12) for a motor vehicle, which is fixed to a sill of the motor vehicle with flanges and an opening (16) for a receiving element in which the jack is placed. The invention also relates to a method for the production of said bracket (12). In order to simplify the production and configuration of the bracket (12) without comprising its stability, the bracket (12) is comprised of a tubular hollow profile (6) and a lid (13), which is fixed on the end (10) opposite the sill of the hollow profile (6) covering said end (10) and which has the opening (16) for the receiving element.

Abstract: A punch designed for producing holes in the walls of hollow parts, the part being subjected to the action of high pressure in the interior by a medium during the punching. In particular when producing hollow parts by the internal high pressure forming process, it is normal practice, following the forming and with the part still located in the forming tool, to make holes in the wall. In order to avoid a drop in the internal high pressure when cutting through the wall of the part, the punch is designed so as to taper at an angle toward the cutting edge in its region plunging into the part to be punched. As a result, sealing of the hole occurs during the punching.

Abstract: The invention relates to a jack bracket (12) for a motor vehicle, which is fixed to a sill of the motor vehicle with flanges and an opening (16) for a receiving element in which the jack is placed. The invention also relates to a method for the production of said bracket (12). In order to simplify the production and configuration of the bracket (12) without comprising its stability, the bracket (12) is comprised of a tubular hollow profile (6) and a lid (13), which is fixed on the end (10) opposite the sill of the hollow profile (6) covering said end (10) and which has the opening (16) for the receiving element.

Abstract: Access to data stored on shared storage media is facilitated by providing a user with uniform access to the user's data regardless from which administrative domain the user is accessing the data. An identifier for the user is created. The identifier corresponds to one account in one administrative domain, but is used in another administrative domain to access data owned by the user, but managed by the one administrative domain. This allows the user running an application in either administrative domain to access its data with the same permissions.

Abstract: The determination of node and/or adapter liveness in a distributed network data processing system is carried out via one messaging protocol that can be assisted by a second messaging protocol which is significantly less susceptible to delay, especially memory blocking delays encountered by daemons running on other nodes. The switching of protocols is accompanied by controlled grace periods for needed responses. This messaging protocol flexibility is also adapted for use as a mechanism for controlling the deliberate activities of node addition (birth) and node deletion (death).

Abstract: In a cluster of computing nodes having shared access to one or more volumes of data storage using a parallel file system, a method for managing the data storage includes initiating a data management application in the cluster using a data management application programming interface (DMAPI) of the parallel file system. When a request submitted to the parallel file system is received on one of the nodes to perform an operation on a file in one of the volumes of data storage, a data management access right is obtained from the DMAPI responsive to the request The operation is performed on the file using the access right.

Abstract: In a cluster of computing nodes having shared access to one or more volumes of data storage using a parallel file system, a method for managing the data storage includes selecting a first one of the nodes to serve as a session manager node, and selecting a second one of the nodes to serve as a session node for a data management application. A session of the data management application is created on the session node by sending a message from the session node to the session manager node, causing the session manager node to distribute information regarding the session among the nodes in the cluster. Responsive to the information distributed by the session manager node, events are received at the session node from the nodes in the cluster for processing by the data management application.

Abstract: A system, method and computer readable medium for providing a snapshot of a subset of a file system. A first snapshot of a first set of source files in a file system is generated. The first snapshot includes an inode corresponding to each source file in the first set of files. Stored in each inode is a first identifier associated with the first set of files and a second identifier associated with the time of the first snapshot. Next, a second snapshot of a second set of source files is taken. The second snapshot includes an inode corresponding to each source file in the second set of files. Stored in each inode are a first identifier and a second identifier. Subsequent snapshots are taken every first period and every second period for the first set of files and the second set of files, respectively.

Abstract: In a cluster of computing nodes having shared access to one or more file systems in data storage using parallel file system software, a method for managing the data storage includes initiating a session of a data management application on a first one of the nodes, while running a user application on a second one of the nodes. A request is submitted to the parallel file system software by the user application on the second node to mount one of the file systems in the data storage. A mount event message is sent from the second node to the first node responsive to the request, for processing by the data management application on the first node. When the file system is to be unmounted, preunmount and unmount events are sent for processing by the data management application on the first node.

Abstract: The decision to prefetch inodes is based upon the detecting of access patterns that would benefit from such a prefetch. Once the decision to prefetch is made, a plurality of inodes are prefetched in parallel. Further, the prefetching of inodes is paced, such that the prefetching substantially matches the speed at which an application requests inodes.

Abstract: An active cluster is dynamically formed to perform a specific task. The active cluster includes one or more data owning nodes of at least one data owning cluster and one or more data using nodes of at least one data using cluster that are to access data of the data owning cluster. The active cluster is dynamic in that the nodes of the cluster are not statically defined. Instead, the active cluster is formed, when a need for such a cluster arises to satisfy a particular task.

Abstract: In a cluster of computing nodes having shared access to one or more volumes of data storage using a parallel file system, a method for managing the data storage includes initiating a session of a data management application on a session node selected from among the nodes in the cluster. The session node receives an event message in a session queue for processing by the data management application, responsive to a request submitted to the parallel file system by a source node among the nodes in the cluster to perform a file operation on a file in the data storage. Following a failure at the session node, the session queue is reconstructed so that processing of the event message by the data management application can continue after recovery from the failure, and the request can be fulfilled at the source node.

Abstract: In a cluster of computing nodes having shared access to one or more volumes of data storage using a parallel file system, a method for managing the data storage includes initiating a session of a data management application on a first one of the nodes, while running a user application on a second one of the nodes. A request is submitted to the parallel file system by the user application on the second node to perform a file operation on a file in one of the volumes of data storage. A data management event message is sent from the second node to the first node responsive to the request, for processing by the data management application on the first node.

Abstract: The acquisition of a lock among nodes of a divided cluster is disclosed. A method is performable by each of at least one node of the cluster. A node waits for a delay corresponding to its identifier. The node asserts intent to acquire the lock by writing its identifier to X and Y variables where another node has failed to acquire the lock. The node waits for another node to acquire the lock where the other node has written to X, and proceeds where Y remains equal to its own identifier. The node waits for another node to acquire the lock where the other node has written to a Z variable, and writes its own identifier to Z and proceeds where the other node has failed. The node writes a value to Y indicating that it is acquiring the lock, and maintains acquisition by periodically writing to Z.

Abstract: The determination of node and/or adapter liveness in a distributed network data processing system is carried out via one messaging protocol that can be assisted by a second messaging protocol which is significantly less susceptible to delay, especially memory blocking delays encountered by daemons running on other nodes. The switching of protocols is accompanied by controlled grace periods for needed responses. This messaging protocol flexibility is also adapted for use as a mechanism for controlling the deliberate activities of node addition (birth) and node deletion (death).

Abstract: Space is allocated on data storage devices in proportion to weights associated with the storage devices. The weights can be dynamically adjusted at any time in order to accommodate changes in the system and to better utilize the storage devices. The technique used to perform the allocating is independent of the weights used by the allocating. Further, the allocation technique can accommodate general purpose data streams having varying lengths and/or varying access patterns, as well as special purpose data streams, such as video streams.

Abstract: A system, method and computer readable medium for providing a snapshot of a subset of a file system. A first snapshot of a first set of source files in a file system is generated. The first snapshot includes an inode corresponding to each source file in the first set of files. Stored in each inode is a first identifier associated with the first set of files and a second identifier associated with the time of the first snapshot. Next, a second snapshot of a second set of source files is taken. The second snapshot includes an inode corresponding to each source file in the second set of files. Stored in each inode are a first identifier and a second identifier. Subsequent snapshots are taken every first period and every second period for the first set of files and the second set of files, respectively.

Abstract: In a cluster of computing nodes having shared access to one or more file systems in data storage using parallel file system software, a method for managing the data storage includes initiating a session of a data management application on a first one of the nodes, while running a user application on a second one of the nodes. A request is submitted to the parallel file system software by the user application on the second node to mount one of the file systems in the data storage. A mount event message is sent from the second node to the first node responsive to the request, for processing by the data management application on the first node. When the file system is to be unmounted, preunmount and unmount events are sent for processing by the data management application on the first node.

Abstract: In a cluster of computing nodes having shared access to one or more volumes of data storage using a parallel file system, a method for managing the data storage includes initiating a session of a data management application on a first one of the nodes, while running a user application on a second one of the nodes. A request is submitted to the parallel file system by the user application on the second node to perform a file operation on a file in one of the volumes of data storage. A data management event message is sent from the second node to the first node responsive to the request, for processing by the data management application on the first node.