Abstract: Systems and methods for allocating resources are disclosed. Resources such as streams are allocated using a stream credit system. Credits are issued to the clients in a manner that ensure the system is operating in a safe allocation state. The credits can be used not only to allocate resources but also to throttle clients where necessary. Credits can be granted fully, partially, and in a number greater than a request. Zero or negative credits can also be issued to throttle clients.

Abstract: Systems and methods for allocating resources are disclosed. Resources such as streams are allocated using a stream credit system. Credits are issued to the clients in a manner that ensure the system is operating in a safe allocation state. The credits can be used not only to allocate resources but also to throttle clients where necessary. Credits can be granted fully, partially, and in a number greater than a request. Zero or negative credits can also be issued to throttle clients.

Abstract: A cache system that includes a reverse cache and a main cache is disclosed. The reverse cache is configured to identify candidates for insertion into a main cache. The reverse cache stores entries such as fingerprints and index values, which are representations of or that identify data. When the entry has been accessed multiple times or is a candidate for promotion based on operation of the reverse cache, data corresponding to the entry is promoted to the main cache. The main cache is configured to evict entries using recency, frequency, and time-adjustments. The main cache and the reverse cache may be similarly configured with a recent list and a frequent list but operate differently.

Abstract: One example method includes performing replication operations and/or failure recovery operations for replication operations in a computing system using matrix clocks. Each node or process in a computing system is associated with a matrix clock that reflects streams required and/or available at the source and destination nodes. As the replication operation is performed, the matrix clocks are updated. When a failure is detected or when insufficient streams are available, the nodes may be throttled until sufficient streams are available. The matrix clocks facilitate a recovery line such that replication can resume when sufficient streams are available.

Abstract: One example method includes performing replication operations and/or failure recovery operations for replication operations in a computing system using matrix clocks and replication controllers. The replication controller includes or has access to vectors of a matrix clock. The replication controller also includes a multiplexer. The multiplexer is configured as an m×n multiplexer using the matrix clock to determine m and n. The operation is performed using the configured multiplexer. This allows an imbalance of resources to be managed by the replication controller. The matrix clock can be updated, which may result in the multiplexer being reconfigured.

Abstract: A cache system that includes a reverse cache and a main cache is disclosed. The reverse cache is configured to identify candidates for insertion into a main cache. The reverse cache stores entries such as fingerprints and index values, which are representations of or that identify data. When the entry has been accessed multiple times or is a candidate for promotion based on operation of the reverse cache, data corresponding to the entry is promoted to the main cache. The main cache is configured to evict entries using recency, frequency, and time-adjustments. The main cache and the reverse cache may be similarly configured with a recent list, a frequent list, and/or ghost lists, but operate differently.

Abstract: One example method includes a cache eviction operation. Entries in a cache are maintained in an entry list that includes a recent list, a recent ghost list, a frequent list, and a frequent ghost list. When an eviction operation is initiated or triggered, timestamps of last access for the entries in the entry list are adjusted by corresponding adjustment values. Candidate entries for eviction are identified based on the adjusted timestamps of last access. At least some of the candidates are evicted from the cache.

Abstract: Systems and methods for allocating resources are disclosed. Resources as processing time, writes or reads are allocated. Credits are issued to the clients in a manner that ensure the system is operating in a safe allocation state. The credits can be used not only to allocate resources but also to throttle clients where necessary. Credits can be granted fully, partially, and in a number greater than requested. Zero or negative credits can also be issued to throttle clients. Segment credits are associated with identifying unique fingerprints or segments and may be allocated by determining how many credits a CPU/cores can support. This maximum number may be divided amongst clients connected with the server.

Abstract: A reverse cache for inserting data into a main cache is disclosed. The reverse cache is configured to identify candidates for insertion into a main cache. The reverse cache stores entries such as fingerprints and index values, which are representations of or that identify data. When the entry has been accessed multiple times or is a candidate for promotion based on operation of the reverse cache, data corresponding to the entry is promoted to the main cache.

Abstract: A reverse cache for inserting data into a main cache is disclosed. The reverse cache is configured to identify candidates for insertion into a main cache. The reverse cache stores entries such as fingerprints, which are representations of data. When the entry has been accessed multiple times or is a candidate for promotion based on operation of the reverse cache, data corresponding to the entry is promoted to the main cache.

Abstract: One example method includes determining a hazard value such as a Weibull hazard function value for an operation such as a recovery operation. Enablement and disablement of a read ahead cache are performed based on the hazard value. The hazard value is representative of whether accesses to a file, such as a backup, being recovered or read are sequential or random. The read ahead cache is enabled when the accesses are sequential or sufficiently sequential.

Abstract: One example method includes performing failure recovery operations in a computing system using matrix clocks. Each node or process in a computing system is associated with a matrix clock. As events and transitions occur in the computing systems, the matrix clocks are updated. The matrix clocks provide a chronological and casual view of the computing system and allow a recovery line to be determined in the event of system failure.

Abstract: One example method includes a cache eviction operation. Entries in a cache are maintained in an entry list that includes a recent list, a recent ghost list, a frequent list, and a frequent ghost list. When an eviction operation is initiated or triggered, timestamps of last access for the entries in the entry list are adjusted by corresponding adjustment values. Candidate entries for eviction are identified based on the adjusted timestamps of last access. At least some of the candidates are evicted from the cache.

Abstract: One example method includes performing failure recovery operations in a computing system using matrix clocks. Each node or process in a computing system is associated with a matrix clock. As events and transitions occur in the computing systems, the matrix clocks are updated. The matrix clocks provide a chronological and casual view of the computing system and allow a recovery line to be determined in the event of system failure.

Abstract: One example method includes a cache eviction operation. Entries in a cache are maintained in an entry list that includes a recent list, a recent ghost list, a frequent list, and a frequent ghost list. When an eviction operation is initiated or triggered, timestamps of last access for the entries in the entry list are adjusted by corresponding adjustment values. Candidate entries for eviction are identified based on the adjusted timestamps of last access. At least some of the candidates are evicted from the cache.

Abstract: One example method includes a cache eviction operation. Entries in a cache are maintained in an entry list that includes a recent list and a frequent list. When an eviction operation is initiated or triggered, timestamps of last access for the entries are adjusted by corresponding adjustment values. Candidates for eviction are identified based on the adjusted timestamps of last access. At least some of the candidates are evicted from the cache.

Abstract: One example method includes a cache eviction operation. Entries in a cache are maintained in an entry list that includes a recent list and a frequent list. When an eviction operation is initiated or triggered, timestamps of last access for the entries are adjusted by corresponding adjustment values. Candidates for eviction are identified based on the adjusted timestamps of last access. At least some of the candidates are evicted from the cache.

Abstract: One example method includes determining a modulus such as a Weibull modulus for a recovery operation. Enablement and disablement of a read ahead cache are performed based on the modulus. The modulus is a linearization of a cumulative distribution function, where failures correspond to non-sequential accesses and successes correspond to sequential accesses.

Abstract: Systems and methods for allocating resources are disclosed. Resources as processing time, writes or reads are allocated. Credits are issued to the clients in a manner that ensure the system is operating in a safe allocation state. The credits can be used not only to allocate resources but also to throttle clients where necessary. Credits can be granted fully, partially, and in a number greater than requested. Zero or negative credits can also be issued to throttle clients. Segment credits are associated with identifying unique fingerprints or segments and may be allocated by determining how many credits a CPU/cores can support. This maximum number may be divided amongst clients connected with the server.

Abstract: Systems and methods for allocating resources are disclosed. Resources as processing time, writes or reads are allocated. Credits are issued to the clients in a manner that ensure the system is operating in a safe allocation state. The credits can be used not only to allocate resources but also to throttle clients where necessary. Credits can be granted fully, partially, and in a number greater than requested. Zero or negative credits can also be issued to throttle clients. Segment credits are associated with identifying unique fingerprints or segments and may be allocated by determining how many credits a CPU/cores can support. This maximum number may be divided amongst clients connected with the server.