Exemplary systems and methods for archiving data objects using secondary copies are disclosed. The system creates one or more secondary copies of primary data that contains multiple data objects. The system may maintain a first data structure that tracks the data objects for which the system has created secondary copies and the locations of the secondary copies. To archive data objects in the primary data, the system identifies data objects to be archived, verifies that previously-created secondary copies of the identified data objects exist, and replaces the identified data objects with stubs. The system may maintain a second data structure that both tracks the stubs and refers to the first data structure, thereby creating an association between the stubs and the locations of the secondary copies.

A user terminal stores security information for each of a plurality of files during a backup of the files. The user terminal also stores information regarding the configuration settings of one or more terminals from which a user may access the plurality of files. During a restore of the files to a remote user terminal, the user terminal at which the restore command was issued utilizes the saved security information to emulate the remote terminal as a virtual endpoint for the files. The user terminal determines whether the user is authorized to access the files within the virtual endpoint based on the saved security information, and restores the files to the remote terminal if the user is authorized for access to the files within the virtual endpoint.

A data recovery method and apparatus are provided. The method retrieving metadata according to a request for data recovery, where the metadata corresponds to a snapshot. A snapshot type of the snapshot is determined according to the metadata, and data recovery is performed according to the snapshot type, to generate recovered data. A false snapshot of the recovered data is generated, and metadata corresponding to the false snapshot is stored.

Methods, systems, and apparatus, including computer programs, providing resilient SCTP stack operation. One method includes having a master and slave for a gateway, the master checkpointing key protocol state, including: for transmissions over an SCTP connection from an application to a peer, checkpointing the message payload when a message is received from the application and before it is pushed to the SCTP protocol; after transmitting data to the peer, checkpointing a stream ID, stream sequence number, and transmission sequence number (TSN) of each chunk; and on receiving a selective acknowledgement (SACK) that a chunk was received, deleting the chunk and checkpointing this deletion; and for receptions of data: on receiving a chunk from the peer, checkpointing a message payload, stream ID, stream sequence number, and TSN before sending a SACK; and upon delivery of a message to the application, deleting the message from the SCTP stack and checkpointing the deletion.

Systems and methods for indexing and searching an event log to determine whether an object of a file system is current. An example method may comprise: arranging a plurality of events into multiple segments, the plurality of events comprising operations affecting a plurality of objects; generating multiple indexes in view of the one or more segments, the indexes comprising a composite index representing the plurality of objects modified by the plurality of events; and inspecting the composite index to determine an object of the plurality of objects is modified by at least one of the plurality of events.

A method for processing snapshots and a distributed block storage system, the method including: acquiring the number of read operations and the number of read/write operations for a data block in a distributed block storage system; on the basis of the number of read operations and the number of read/write operations, determining a target snapshot manner, wherein the target snapshot manner includes copying while writing or re-orienting while writing; on the basis of the target snapshot manner, performing a snapshot operation on the data block in the distributed block storage system.

A method and system of checkpointing single process application groups and multi-process application groups. In an exemplary embodiment, the method may include creating at least one full checkpoint for each application in an application group, and creating at least one incremental application checkpoint for each application in the application group. Further, each of the at least one incremental application checkpoint may be automatically merged against a corresponding full application checkpoint. Further, checkpointing may be synchronized across all applications in the application group. In the exemplary embodiment, each application may use both fork( ) and exec( ) in any combination.

An apparatus comprises a memory unit, and a control unit connected to the memory unit. The apparatus can be configured to interface at least one access node; the control unit is configured to derive at least one local level security key within an established security context for a terminal, forward the derived local security key to at least one access node, and detect failures in a handover for a terminal being served by a first access node towards a second access node. The failures concern the interface between the apparatus and the second access node. In response to a verified trigger condition, the control unit can re-adjust local level security keys with keys maintained at the terminal within the established security context.

The present disclosure describes methods and system configurations for failover of cluster computing system resources, for a cluster computing system including a plurality of cluster nodes. In some examples, operations are performed to monitor an abstracted resource and reconfigure the abstracted resource, to enable fail-over processing for component members of the abstracted resource. In further examples, a hierarchy of resource dependencies is defined to enable enhanced fail-over processing for the failure of abstracted resources that cause the failure of services within the cluster computing system that are dependent upon the abstracted resources.

A system and method for providing a watchdog timer to enable collection of crash data is provided. Upon execution of certain operations, a source thread of an application initiates a watchdog thread that periodically sample state of data relating to the application. Should the operation not complete within a watchdog timeout period, the watchdog thread invokes a crash function to collect additional state data. At least a portion of the state data is stored for later analysis and debugging.