Abstract: Provided is a method of synchronizing a distributed object store including a plurality of data stores, the method including bringing a first data store of the data stores online after having been offline, choosing a second data store of the data stores, the second data store being online while the first data store was offline, reading, by the first data store, an entry from a catch-up log, and performing a data modification operation corresponding to the entry on the first data store to synchronize the plurality of data stores.

Abstract: A storage system. In some embodiments, the storage system includes a plurality of object stores, and a plurality of data managers, connected to the object stores. The plurality of data managers may include a plurality of processing circuits. A first processing circuit of the plurality of processing circuits may be configured to process primarily input-output operations, and a second processing circuit of the plurality of processing circuits may be configured to process primarily input-output completions.

Abstract: A method of contention-free lookup including mapping a key of a cache lookup operation to determine an expected location of object data, walking a collision chain by determining whether a cache header signature matches a collision chain signature, when the cache header signature does not match, again walking the collision chain, when the cache header signature matches, determining whether a key in the cache header signature matches the key of the cache lookup operation, when the key does not match, reading a cache entry corresponding to the cache lookup operation, and repopulating the cache entry, when the key matches, acquiring an entry lock, and determining whether the key still matches after acquiring the entry lock, when the key still matches finding the object data in the expected location, and when the key no longer matches, releasing the entry lock, and again walking the collision chain.

Abstract: A method of contention-free lookup including mapping a key of a cache lookup operation to determine an expected location of object data, walking a collision chain by determining whether a cache header signature matches a collision chain signature, when the cache header signature does not match, again walking the collision chain, when the cache header signature matches, determining whether a key in the cache header signature matches the key of the cache lookup operation, when the key does not match, reading a cache entry corresponding to the cache lookup operation, and repopulating the cache entry, when the key matches, acquiring an entry lock, and determining whether the key still matches after acquiring the entry lock, when the key still matches finding the object data in the expected location, and when the key no longer matches, releasing the entry lock, and again walking the collision chain.

Abstract: Provided is a method of synchronizing a distributed object store including a plurality of data stores, the method including bringing a first data store of the data stores online after having been offline, choosing a second data store of the data stores, the second data store being online while the first data store was offline, reading, by the first data store, an entry from a catch-up log, and performing a data modification operation corresponding to the entry on the first data store to synchronize the plurality of data stores.

Abstract: A method of contention-free lookup including mapping a key of a cache lookup operation to determine an expected location of object data, walking a collision chain by determining whether a cache header signature matches a collision chain signature, when the cache header signature does not match, again walking the collision chain, when the cache header signature matches, determining whether a key in the cache header signature matches the key of the cache lookup operation, when the key does not match, reading a cache entry corresponding to the cache lookup operation, and repopulating the cache entry, when the key matches, acquiring an entry lock, and determining whether the key still matches after acquiring the entry lock, when the key still matches finding the object data in the expected location, and when the key no longer matches, releasing the entry lock, and again walking the collision chain.

Abstract: Provided is a method of cache entry management, the method comprising determining, by a cache manager, a level of importance for each of a plurality of cache entries, assigning, by the cache manager, a metadata type for each of the cache entries based upon the determined level of importance, determining, by the cache manager, a frequency of access of each of the cache entries, generating, by the cache manager, a heat map based upon the determined frequency of access of the cache entries, and determining, by the cache manager, which one of at least two of the cache entries to evict based upon the respective metadata types and the respective frequencies of access.

Abstract: A method for accessing data stored in a target of a data storage system includes: running a plurality of transport threads on a first group of CPUs, wherein each of the plurality of transport threads comprises a command receiver path and a command transmitter path; running a plurality of data path threads on a second group of CPUs, wherein each of the plurality of data path threads comprises a command issue path and a command completion path; posting an I/O command to an I/O command issue queue using the command receive path of a transport thread, and processing the I/O command using the command issue path of a data path thread; and posting an I/O completion notification to an I/O completion queue using the command completion path of the data path thread, and processing the I/O completion notification using the command transmitter path of the transport thread.

Abstract: A method for accessing data stored in a target of a data storage system includes: running a plurality of transport threads on a first group of CPUs, wherein each of the plurality of transport threads comprises a command receiver path and a command transmitter path; running a plurality of data path threads on a second group of CPUs, wherein each of the plurality of data path threads comprises a command issue path and a command completion path; posting an I/O command to an I/O command issue queue using the command receive path of a transport thread, and processing the I/O command using the command issue path of a data path thread; and posting an I/O completion notification to an I/O completion queue using the command completion path of the data path thread, and processing the I/O completion notification using the command transmitter path of the transport thread.