Abstract: A virtual file system and method for performing virtual file system operations uses a vnode descriptor to access a vnode for a vnode operation. If the vnode is not found in a vnode cache using the vnode descriptor, the vnode is reconstructed using information regarding the vnode found outside of the vnode cache using the vnode descriptor.

Abstract: The present invention is directed to methods of and systems for ranking results returned by a search engine. A method in accordance with the invention comprises determining a formula having variables and parameters, wherein the formula is for computing a relevance score for a document and a search query; and ranking the document based on the relevance score. Preferably, determining the formula comprises tuning the parameters based on user input. Preferably, the parameters are determined using a machine learning technique, such as one that includes a form of statistical classification.

Abstract: System and method for accessing a distributed storage system uses a storage-level access control process at a distributed file system that interfaces with the distributed storage system to determine whether a particular client has access to a particular first file system object using an identifier of the particular client and storage-level access control rules in response to a file system request from the particular client to access a second file system object in the particular first file system. The storage-level access control rules are defined for a plurality of clients and a plurality of first file system objects of the distributed storage system to allow the particular client access to the second file system object in the particular first file system object only if the particular client has been determined to have access to the particular first file system object according to the storage-level access control rules.

Abstract: A file system uses a B-tree data structure to organize file data. The file system may maintain an index node (mode) representing a file and having entries that map to extents of the file. When the file system detects an index node, through updates, has exceeded a threshold number of extents, the file system converts the file to a copy-on-write (COW) B-tree data structure containing the entries representing the extents of the file. To clone the file, the file system uses copies of the index node and the root node of the COW B-tree data structure.

Abstract: A sorted key-value store is implemented using a write-back cache maintained in memory, a B-tree data structured maintained in disk, and a logical and physical log for providing transactions. The logical log and write-back cache are used to answer client requests, while dirty blocks in the write-back cache are periodically flushed to disk using the physical log.

Abstract: A method of determining relevancies of objects to a search query includes associating multiple tags with multiple objects, recording bookmarks to the multiple objects, or both, and determining a relevance score for each of the multiple objects and a search query. One embodiment of the method combines full-text relevance algorithms with tag relevance algorithms. Other embodiments include statistical relevance algorithms such as statistical classification or rank regression algorithms. When a user executes a search query, a results list containing the objects is returned, with the objects organized based on the relevance scores. The objects are organized by, for example, listing those with the highest relevance scores first or by marking them with an indication of their relevance.

Abstract: Exemplary methods, apparatuses, and systems include a controller node receiving a request to perform a consistency check of a distributed file system. The controller node transmits, to each of a plurality of nodes, a request for the node to use logical metadata of the distributed file system owned by the node to construct an expected copy of physical metadata mapped to the logical metadata, determine which of the plurality of nodes own actual portions of the physical metadata, transmit corresponding portions of the expected copy of the physical metadata to each of the nodes determined to own actual portions of the physical metadata, and compare expected copies of the physical metadata received from other nodes to the actual physical metadata owned by the node. The controller node receives a result of the comparison from each of the nodes, aggregates the received results, and generates an error report.

Abstract: A method of determining relevancies of objects to a search query includes associating multiple tags with multiple objects, recording bookmarks to the multiple objects, or both, and determining a relevance score for each of the multiple objects and a search query. One embodiment of the method combines full-text relevance algorithms with tag relevance algorithms. Other embodiments include statistical relevance algorithms such as statistical classification or rank regression algorithms. When a user executes a search query, a results list containing the objects is returned, with the objects organized based on the relevance scores. The objects are organized by, for example, listing those with the highest relevance scores first or by marking them with an indication of their relevance.

Abstract: System and method for supporting a user-level file system transaction use cloned files of original existing files specified in the user-level file system transaction to perform file system operations on at least one of the original existing files using the cloned files, which include metadata of the original existing files. After at least one of the cloned files have been modified, a batch rename operation is executed to atomically commit every modified cloned file of the user-level file system transaction.

Abstract: System and method for managing storage metadata utilize a metadata data structure containing allocation information of storage blocks of a storage system in which a portion of the metadata data structure that corresponds to a group of the storage blocks can be reserved to a requesting client, which then manages the portion of the metadata data structure using a copy of the portion of the metadata data structure.

Abstract: A file system uses a B-tree data structure to organize file data. The file system may maintain an index node (mode) representing a file and having entries that map to extents of the file. When the file system detects an index node, through updates, has exceeded a threshold number of extents, the file system converts the file to a copy-on-write (COW) B-tree data structure containing the entries representing the extents of the file. To clone the file, the file system uses copies of the index node and the root node of the COW B-tree data structure.

Abstract: System and method for accessing a distributed storage system uses a storage-level access control process at a distributed file system that interfaces with the distributed storage system to determine whether a particular client has access to a particular first file system object using an identifier of the particular client and storage-level access control rules in response to a file system request from the particular client to access a second file system object in the particular first file system. The storage-level access control rules are defined for a plurality of clients and a plurality of first file system objects of the distributed storage system to allow the particular client access to the second file system object in the particular first file system only if the particular client has been determined to have access to the particular first file system object according to the storage-level access control rules.

Abstract: A virtualized computing system for executing a distributed computing application, such as Hadoop, is discussed. The virtualized computing system stores data in a distributed filesystem, such as Hadoop Distributed File System, and processes data using a topology awareness that takes into account the virtualization layer of the virtualized computing system. The virtualized computing system employs locality-related policies, including replica placement policies, replica choosing policies, balancer policies, and task scheduling policies that take advantage of the awareness of the virtualization topology.

Abstract: A transaction manager for handling operations on data in a storage system provides a system for executing transactions that uses a versioned tuple cache to achieve fast, abortable transactions using a redo-only log. The transaction manager updates an in-memory key-value store and also attaches a transaction identifier to the tuple as a minor key. Opportunistic locking can be accomplished due to the low cost of aborting transactions.

Abstract: A sorted key-value store is implemented using a write-back cache maintained in memory, a B-tree data structured maintained in disk, and a logical and physical log for providing transactions. The logical log and write-back cache are used to answer client requests, while dirty blocks in the write-back cache are periodically flushed to disk using the physical log.

Abstract: Systems and methods for allocating space in persistent storage are provided. A modified bitmap and a tree of bitmap summary pages are used to manage the free space of a large scale storage system. The bitmap is separated into fixed size pages and has bitmap summary entries to summarize the information in the bitmap. Bitmap summary pages can be further summarized into secondary summary pages. The tree data structure can continue to N levels until a topmost level has one bitmap summary page.

Abstract: A virtual file system and method for performing virtual file system operations uses a vnode descriptor to access a vnode for a vnode operation. If the vnode is not found in a vnode cache using the vnode descriptor, the vnode is reconstructed using information regarding the vnode found outside of the vnode cache using the vnode descriptor.

Abstract: The present invention is directed to methods of and systems for ranking results returned by a search engine. A method in accordance with the invention comprises determining a formula having variables and parameters, wherein the formula is for computing a relevance score for a document and a search query; and ranking the document based on the relevance score. Preferably, determining the formula comprises tuning the parameters based on user input. Preferably, the parameters are determined using a machine learning technique, such as one that includes a form of statistical classification.

Abstract: A system for and a method of using user-entered information to return more meaningful information in response to Internet search queries are disclosed. A method in accordance with the present invention comprises managing a database in response to multiple user inputs and displaying search results from the database in response to a search query. The search results include a results list and supplemental data related to the search query. Managing the database includes, among other things, re-ranking elements in the results list, storing information related to relevancies of elements in the results list, blocking a link in the results list, storing links to documents related to the search query, or any combination of these. The supplemental data include descriptions of or indices to one or more concepts related to the search query.

Abstract: The present invention is directed to methods of and systems for ranking results returned by a search engine. A method in accordance with the invention comprises determining a formula having variables and parameters, wherein the formula is for computing a relevance score for a document and a search query; and ranking the document based on the relevance score. Preferably, determining the formula comprises tuning the parameters based on user input. Preferably, the parameters are determined using a machine learning technique, such as one that includes a form of statistical classification.