Abstract: A distributed metadata cache for a distributed object store includes a plurality of cache entries, an active-cache-entry set and an unreferenced-cache-entry set. Each cache entry includes information relating to whether at least one input/output (IO) thread is referencing the cache entry and information relating to whether the cache entry is no longer referenced by at least one IO thread. Each cache entry in the active-cache-entry set includes information that indicates that at least one IO thread is actively referencing the cache entry. Each cache entry in the unreferenced-cache-entry set is eligible for eviction from the distributed metadata cache by including information that indicates that the cache entry is no longer actively referenced by an IO thread.

Abstract: A distributed metadata cache for a distributed object store includes a plurality of cache entries, an active-cache-entry set and an unreferenced-cache-entry set. Each cache entry includes information relating to whether at least one input/output (IO) thread is referencing the cache entry and information relating to whether the cache entry is no longer referenced by at least one IO thread. Each cache entry in the active-cache-entry set includes information that indicates that at least one IO thread is actively referencing the cache entry. Each cache entry in the unreferenced-cache-entry set is eligible for eviction from the distributed metadata cache by including information that indicates that the cache entry is no longer actively referenced by an IO thread.

Abstract: A system and a method are disclosed that efficiently supports an append operation in an object storage system. A size of data received with a request for an append operation from an application is determined based on a data-alignment characteristic of a storage medium. Data that is not aligned with the data-alignment characteristic is stored in persistent memory and aggregated with other data from the application that is not aligned with the data-alignment characteristic, while data that is aligned with the data-alignment characteristic is stored directly in the storage medium. Aggregated data that becomes aligned with the data-alignment characteristic as additional requests for append operations are received are migrated to the storage medium.

Abstract: A method for mapping an object store may include storing a data entry within a mapping page for an object in the object store, wherein the data entry may include a key and a value, and the value may include an address for the object in the object store. The method may further include storing multiple data entries within the mapping page for multiple corresponding objects in the object store, wherein each data entry may include a key and one or more values for a corresponding object in the object store, and each value may include an address for the corresponding object in the object store. The data entries may be part of a mapping data structure which may include nodes, and each node may be stored within a mapping page.

Abstract: A system and a method are disclosed that provides a data replication management technique for a distributed environment that eliminates a need to order members of a replica set. A node of a node cluster in the distributed system may be configured to send in parallel an IO request to each respective member of the replica set. Reponses are received from members of the replica set that indicate a completion status of the IO request at the replica set member sending the IO response. A request is sent to other nodes of the node cluster to remove a replica from the replica set based on an error response received from the replica. The replica that responded with the error response is removed from the replica set based on an agreement of nodes of the node cluster to remove the replica from the replica set.

Abstract: A method for mapping an object store may include storing a data entry within a mapping page for an object in the object store, wherein the data entry may include a key and a value, and the value may include an address for the object in the object store. The method may further include storing multiple data entries within the mapping page for multiple corresponding objects in the object store, wherein each data entry may include a key and one or more values for a corresponding object in the object store, and each value may include an address for the corresponding object in the object store. The data entries may be part of a mapping data structure which may include nodes, and each node may be stored within a mapping page.

Abstract: A distributed metadata cache for a distributed object store includes a plurality of cache entries, an active-cache-entry set and an unreferenced-cache-entry set. Each cache entry includes information relating to whether at least one input/output (IO) thread is referencing the cache entry and information relating to whether the cache entry is no longer referenced by at least one IO thread. Each cache entry in the active-cache-entry set includes information that indicates that at least one IO thread is actively referencing the cache entry. Each cache entry in the unreferenced-cache-entry set is eligible for eviction from the distributed metadata cache by including information that indicates that the cache entry is no longer actively referenced by an IO thread.

Abstract: A distributed metadata cache for a distributed object store includes a plurality of cache entries, an active-cache-entry set and an unreferenced-cache-entry set. Each cache entry includes information relating to whether at least one input/output (IO) thread is referencing the cache entry and information relating to whether the cache entry is no longer referenced by at least one IO thread. Each cache entry in the active-cache-entry set includes information that indicates that at least one IO thread is actively referencing the cache entry. Each cache entry in the unreferenced-cache-entry set is eligible for eviction from the distributed metadata cache by including information that indicates that the cache entry is no longer actively referenced by an IO thread.

Abstract: A system and a method are disclosed that efficiently supports an append operation in an object storage system. A size of data received with a request for an append operation from an application is determined based on a data-alignment characteristic of a storage medium. Data that is not aligned with the data-alignment characteristic is stored in persistent memory and aggregated with other data from the application that is not aligned with the data-alignment characteristic, while data that is aligned with the data-alignment characteristic is stored directly in the storage medium. Aggregated data that becomes aligned with the data-alignment characteristic as additional requests for append operations are received are migrated to the storage medium.

Abstract: A system and a method are disclosed that provides a data replication management technique for a distributed environment that eliminates a need to order members of a replica set. A node of a node cluster in the distributed system may be configured to send in parallel an IO request to each respective member of the replica set. Reponses are received from members of the replica set that indicate a completion status of the IO request at the replica set member sending the IO response. A request is sent to other nodes of the node cluster to remove a replica from the replica set based on an error response received from the replica. The replica that responded with the error response is removed from the replica set based on an agreement of nodes of the node cluster to remove the replica from the replica set.

Abstract: A method for mapping an object store may include storing a data entry within a mapping page for an object in the object store, wherein the data entry may include a key and a value, and the value may include an address for the object in the object store. The method may further include storing multiple data entries within the mapping page for multiple corresponding objects in the object store, wherein each data entry may include a key and one or more values for a corresponding object in the object store, and each value may include an address for the corresponding object in the object store. The data entries may be part of a mapping data structure which may include nodes, and each node may be stored within a mapping page.

Abstract: A distributed metadata cache for a distributed object store includes a plurality of cache entries, an active-cache-entry set and an unreferenced-cache-entry set. Each cache entry includes information relating to whether at least one input/output (IO) thread is referencing the cache entry and information relating to whether the cache entry is no longer referenced by at least one IO thread. Each cache entry in the active-cache-entry set includes information that indicates that at least one IO thread is actively referencing the cache entry. Each cache entry in the unreferenced-cache-entry set is eligible for eviction from the distributed metadata cache by including information that indicates that the cache entry is no longer actively referenced by an IO thread.

Abstract: According to one embodiment, a method includes: assigning a target port to a control path thread of an application to access data stored in a storage device of a data storage system; creating a storage device path corresponding to the target port; running the data path thread to access the data stored in the storage device; and running a control path thread to process a management work request to operate on one of objects including the target port, the storage device path, and the storage device. The control path thread is configured to send the management work request to the data path thread asynchronously. The data path thread is configured to complete the management work request and send a management work request completion response to the control path thread asynchronously.

Abstract: According to one embodiment, a method includes: assigning a target port to a control path thread of an application to access data stored in a storage device of a data storage system; creating a storage device path corresponding to the target port; running the data path thread to access the data stored in the storage device; and running a control path thread to process a management work request to operate on one of objects including the target port, the storage device path, and the storage device. The control path thread is configured to send the management work request to the data path thread asynchronously. The data path thread is configured to complete the management work request and send a management work request completion response to the control path thread asynchronously.