High performance space efficient distributed storage is disclosed. For example, a distributed storage volume (DSV) is deployed on a plurality of hosts, with a first host storing a local cache, and a storage controller executing on a processor of the first host receives a request to store a first file. The first file is stored to the local cache. The DSV is queried to determine whether a second file that is a copy of the first file is stored in the DSV. In response to determining that the DSV lacks the second file, the first file is transferred from the local cache to the DSV and then replicated to a second host of the plurality of hosts. In response to determining that the second file resides in the DSV, a reference to the second file is stored in the DSV and then replicated to the second host.

A method for maintaining statistics for data elements in a cache is disclosed. The method maintains a heterogeneous cache comprising a higher performance portion and a lower performance portion. The method maintains, within the lower performance portion, a ghost cache containing statistics for data elements that are currently contained in the heterogeneous cache, and data elements that have been demoted from the heterogeneous cache within a specified time interval. The method calculates a size of the ghost cache based on an amount of frequently accessed data that is stored in backend storage volumes behind the heterogeneous cache. The method alters the size of the ghost cache as the amount of frequently accessed data changes. A corresponding system and computer program product are also disclosed.

Described herein are method and apparatus for servicing software components of nodes of a cluster storage system. During data-access sessions with clients, client IDs and file handles for accessing files are produced and stored to clients and stored (as session data) to each node. A serviced node is taken offline, whereby network connections to clients are disconnected. Each disconnected client is configured to retain its client ID and file handles and attempt reconnections. Session data of the serviced node is made available to a partner node (by transferring session data to the partner node). After clients have reconnected to the partner node, the clients may use the retained client IDs and file handles to continue a data-access session with the partner node since the partner node has access to the session data of the serviced node and thus will recognize and accept the retained client ID and file handles.

A system, method and apparatus to facilitate data exchange via pointers. For example, in a computing system having a first processor and a second processor that is separate and independent from the first processor, the first processor can run a program configured to use a pointer identifying a virtual memory address having an ID of an object and an offset within the object. The first processor can use the virtual memory address to store data at a memory location in the computing system and/or identify a routine at the memory location for execution by the second processor. After the pointer is communicated from the first processor to the second processor, the second processor can access the same memory location identified by the virtual memory address. The second processor may operate on the data stored at the memory location or load the routine from the memory location for execution.

A method for compressing data in a local cache of a web server is described. A local cache compression engine accesses values in the local cache and determines a cardinality of the values of the local cache. The local cache compression engine determines a compression rate of a compression algorithm based on the cardinality of the values of the local cache. The compression algorithm is applied to the cache based on the compression rate to generate a compressed local cache.

Data base performance is improved using write-behind optimization of covering cache. Non-volatile memory data cache includes a full copy of stored data file(s). Data cache and storage writes, checkpoints, and recovery may be decoupled (e.g., with separate writes, checkpoints and recoveries). A covering data cache supports improved performance by supporting database operation during storage delays or outages and/or by supporting reduced I/O operations using aggregate writes of contiguous data pages (e.g., clean and dirty pages) to stored data file(s). Aggregate writes reduce data file fragmentation and reduce the cost of snapshots. Performing write-behind operations in a background process with optimistic concurrency control may support improved database performance, for example, by not interfering with write operations to data cache. Data cache may store (e.g., in metadata) data cache checkpoint information and storage checkpoint information. A stored data file may store storage checkpoint information (e.g., in a file header).

A shared data management system configured to receive frames comprising data from one or more producer devices and to transmit reconstructed frames to one or more consumer devices, a producer device and a consumer device being connected to the shared data management system by way of a communication network using a communication protocol. The shared data management system comprises a memory system having one or more memories. The shared data management system advantageously comprises a central controller configured to store at least some of the data encapsulated in a frame received from a producer device in a target memory area of the memory system, the central controller being configured to compute, for each datum to be stored, the address of the target memory based on an index associated with the datum in the received frame.

A storage system includes a CPU, a first memory module, a second memory module, and a storage device. The processor and the first memory module are installed in the same node. The second memory module are replaceable without shutting down power supply of the node. The first memory module stores an operating system and a program for managing user data to be stored in the storage device. The second memory module stores cache data of the user data to be stored in the storage device. The processor is configured to store a copy of data to be stored in the second memory module in the third memory module.

Techniques for implementing user-space remote memory paging are provided. In one set of embodiments, these techniques include a user-space remote memory paging (RMP) runtime that can: (1) pre-allocate one or more regions of remote memory for use by an application; (2) at a time of receiving/intercepting a memory allocation function call invoked by the application, map the virtual memory address range of the allocated local memory to a portion of the pre-allocated remote memory; (3) at a time of detecting a page fault directed to a page that is mapped to remote memory, retrieve the page via Remote Direct Memory Access (RDMA) from its remote memory location and store the retrieved page in a local main memory cache; and (4) on a periodic basis, identify pages in the local main memory cache that are candidates for eviction and write out the identified pages via RDMA to their mapped remote memory locations if they have been modified.

An information processing apparatus includes a network interface, a storage device, and a processor. The processor is configured to assign a plurality of zones in the storage device. Each of the zones is a contiguous physical address range of the storage device that is mapped to a contiguous logical address range. The processor is configured to generate zone management information for each of the plurality of zones, store content received from the origin server via the network interface, in one of writable zones and update a writable address of the zone management information for the one of the writable zones. The processor is configured to operate to transmit the received content, and control the storage device to delete data stored therein in units of a zone upon a predetermined cache clearing criteria being met.