Micron Technology Incorporated

Other

Steven Moyer

Alexander Tomlinson

David Boles

John M Groves

Nabeel Meeramohideen Mohamed

Greg A Becker

David Andrew Roberts

Jacob Mulamootil Jacob

Pierre Labat

Sudheer Kurichiyath

Tomoko Ogura Iwasaki

Manik Advani

Gaurav Sanjay Ramdasi

Tristan Antonio Partin

Methods, systems, and devices for access heatmap implementations at a host device are described. A host device may leverage access operation monitoring that is performed at a memory device, including various examples of signaling and management of monitoring configurations. For example, a memory device may maintain a storage location for tracking access operation occurrence, for which access operations of a given address may be mapped to multiple fields, and for which each field may be associated with access operations of a respective subset of the addresses. In some examples, such registers may be configured or accessed based on indications (e.g., commands, requests) from a host device, which may support dynamic access operation monitoring that is responsive to various operating conditions. In some examples, the host device may perform evaluations based on such minimum values associated with respective addresses to determine a distribution of data across various portions of memory.

Access heatmap implementations at a host device

Systems and techniques for reducing probabilistic filter query latency are described herein. A query for a probabilistic filter that is stored on a first media may be received from a caller. In response to receiving the query, cached segments of the probabilistic filter stored on a second media may be obtained. Here, the probabilistic filter provides a set membership determination that is conclusive in a determination that an element is not in a set. The query may be executed on the cached segments resulting in a partial query result. Retrieval of remaining data of the probabilistic filter from the first media to the second media may be initiated without intervention from the caller. Here, the remaining data corresponds to the query and data that is not in the cached segment. The partial query results may then be returned to the caller.

Reducing probabilistic filter query latency

Methods, systems, and devices for access heatmap generation at a memory device are described. In some examples, a memory device may maintain a register for tracking access operation occurrence, for which access operations of an address of the memory device may be mapped to multiple fields of the register. In some cases, in response to a first access operation performed on a first address of the memory device, the memory device may increment a first field and a second field of the register and, in response to a second access operation performed on a second address of the memory device, the memory device may increment the first field and a third field of the register. In some examples, the memory device may maintain a second register having a set of fields that each indicate a respective address for which an access occurrence satisfies a threshold.

Techniques to generate access heatmaps at a memory device

Methods, systems, and devices for techniques to balance log structured merge trees are described. A computing system may rebalance a tree structure having an ordered set of leaf nodes by splitting or joining leaf nodes of the tree structure. To split a leaf node, the computing system may select a key to evenly partition key and value data stored in the leaf. The computing system may place each key block of the leaf node having keys less than or equal to the selected key in a first new leaf node, and may place each key block of the leaf node having keys greater than the selected key in a second new leaf node. To join leaf nodes of the tree structure, the computing system may place each key block and each value block of the leaf node and the adjacent leaf node in a new leaf node.

Techniques to balance log structured merge trees

Methods, systems, and devices for techniques to group media blocks are described. In some cases, a computing system may generate a memory map for a preconfigured size or chunk of data. For example, the computing system may divide files of media blocks into a set of fixed sized chunks of consecutive media blocks. Upon an application requesting a memory map for a set of media blocks, a storage layer of the computing system may generate a sub-map of the memory map for each chunk of data containing a media block of the set of requested media blocks. In some cases, the computing system may assign the chunks of data a continuous range of addresses in the virtual address space of the application. Upon generating the memory map, the storage layer may return an indication of the virtual address ranges of the requested media blocks to the application.

Techniques to group media blocks

A system includes a memory device, and a processing device, operatively coupled with the memory device, to perform operations including detecting a failure of a key-value store, identifying a non-filled zone of the memory device resulting from the failure, wherein the non-filled zone stores, in the key-value store, at least one of: an uncommitted key block or an uncommitted value block, and recovering the non-filled zone to obtain a recovered zone.

Zoned memory device recovery after a key-value store failure

A system and method for updating a configuration of a host system so that the memory sub-system of the host system emulates performance characteristics of a target memory sub-system. An example system includes a memory sub-system; and a processor, operatively coupled with the memory sub-system, to perform operations comprising receiving a request to emulate a characteristic of a target memory sub-system, identifying a candidate configuration that generates a load on a memory sub-system of a host system to decrease a characteristics of the memory sub-system of the host system, and updating a configuration of the host system based at least on the candidate configuration, wherein the updated configuration changes the memory sub-system of the host system to emulate the characteristic of the target memory sub-system.

Emulating memory sub-systems that have different performance characteristics

A memory system includes a memory device comprising a content addressable memory (CAM) block comprising a plurality of key tables each storing a respective plurality of stored search keys. The memory system further includes a processing device that receives, from a requestor, an input search key and an indication of one of the plurality of key tables and identifies a match between the input search key and one of the plurality of stored search keys in the one of the plurality of key tables. The one of the plurality of stored search keys has an associated offset value indicating a location in a sorted string table (SSTable) corresponding to the one of the plurality of key tables. The processing device further reads the offset value from the one of the plurality of key tables and returns, to the requestor, the offset value read from the one of the plurality of key tables. The requestor can retrieve, from the location in the SSTable, data representing a value associated with the input search key.

Key storage for sorted string tables using content addressable memory

A system includes a zoned memory device allocating a zone storing a block belonging to a key-value set, and a processing device, operatively coupled with the zoned memory device, to perform operations including obtaining zone status information associated with the zone, identifying that the zone is a non-filled zone in view of the zone status information, and recovering the non-filled zone to obtain a recovered zone.

A system and method for updating a configuration of a host system so that the memory sub-system of the host system emulates performance characteristics of a target memory sub-system. An example system determining a configuration of the host system, the host system comprising a memory sub-system; receiving, by a processing device, a request to emulate a characteristic of a target memory sub-system; analyzing a plurality of candidate configurations for the host system, wherein the plurality of candidate configurations comprises a candidate configuration that generates a load on the memory sub-system to decrease characteristics of the memory sub-system; and updating the configuration of the host system based on the plurality of candidate configurations, wherein the updated configuration changes the memory sub-system to emulate the characteristic of the target memory sub-system.

Aspects of the present disclosure provide for operations of a key-value store (KVS) that uses journaling with storage of data (e.g., key data or value data of a key-value pair) in different types of data storage objects (e.g., data storage formats) selected based on one or more criteria.

Key-value store using journaling with selective data storage format

A KVS tree database and operations thereon are described herein. A KVS tree database is a multilevel tree that includes a base level and subsequent levels. The base level includes a heterogeneous kvset in a node, The heterogeneous kvset including entries for multiple KVS trees, such as a first entry for a first KVS tree and a second entry for a second KVS tree, The subsequent level includes a first node including a first homogeneous kvset for the first KVS tree and a second node including a second homogeneous kvset for the second KVS tree. Here, a homogeneous kvset includes nodes from only one KVS tree. The KVS tree database also includes a first determinative mapping of entries between the base level and the subsequent level and a second determinative mapping of entries between subsequent levels.

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Round Rock, TX, United States of America

Steven Moyer