Abstract: Methods and systems are provided for tracking object instances stored on a plurality of network nodes, which tracking enables a global determination of when an object has no references across the networked nodes and can be safely de-allocated. According to one aspect of the invention, each node has a local object store for tracking and optionally storing objects on the node, and the local object stores collectively share the locally stored instances of the objects across the network. One or more applications, e.g., a file system and/or a storage system, use the local object stores for storing all persistent data of the application as objects.

Abstract: A digitally signed file system in which data, metadata and files are objects, each object having a globally unique and content-derived fingerprint and wherein object references are mapped by the fingerprints; the file system has a root object comprising a mapping of all object fingerprints in the file system, such that a change to the file system results in a change in the root object, and tracking changes in the root object provides a history of file system activity.

Abstract: Method and apparatus for constructing an index that scales to a large number of records and provides a high transaction rate. New data structures and methods are provided to ensure that an indexing algorithm performs in a way that is natural (efficient) to the algorithm, while a non-uniform access memory device sees IO (input/output) traffic that is efficient for the memory device. One data structure, a translation table, is created that maps logical buckets as viewed by the indexing algorithm to physical buckets on the memory device. This mapping is such that write performance to non-uniform access SSD and flash devices is enhanced. Another data structure, an associative cache is used to collect buckets and write them out sequentially to the memory device as large sequential writes. Methods are used to populate the cache with buckets (of records) that are required by the indexing algorithm.