Microsoft Technology Licensing, LLC

Huseyin Simitci

Aaron William Ogus

Bradley Gene Calder

Cheng Huang

Sergey M Yekhanin

Yikang Xu

Shane Kumar Mainali

Ju Wang

Andrew James Edwards

Parikshit Santhan Gopalan

Ioan Oltean

Jin Li

Haiyong Wang

Ramesh Shankar

Parikshit Santhana Gopalan

In various embodiments, methods and systems for implementing a distributed metadata management system in distributed storage systems are provided. A distributed storage system operates based on data storage resources (e.g., extents and streams). The distributed metadata management system is implemented for extent and stream metadata to facilitate the scalability of metadata processing. The distributed storage system implements extent managers and stream managers that independently manage extent and stream metadata, respectively. The extent managers are associated with an extent table that stores extent metadata. The stream managers are associated with streams that store associations with extents. The distributed metadata management system can also utilize a bootstrap layer that leverages components of a legacy distributed storage system to facilitate distributed management of extent and stream metadata. The bootstrap layer is used to store the extent table as a system table and to persist the state of the stream manager as system streams.

Distributed metadata management in a distributed storage system

In various embodiments, methods and systems for implementing garbage collection in distributed storage systems are provided. The distributed storage system operates based on independent management of metadata of extent and stream data storage resources. A hybrid garbage collection system based on reference counting garbage collection operations and mark-and-sweep garbage collection operations is implemented. An extent lifetime table that tracks reference weights and mark sequences for extents is initialized and updated based on indications from extent managers and stream managers, respectively. Upon determining that an extent is to be handed-off from weighted reference counting garbage collection operations to mark-and-sweep garbage collection operations, a reference weight field for the extent is voided and a mark sequence field of the extent is updated. The mark sequence field is updated with a latest global sequence number. The mark-and-sweep garbage collection operations are utilized to reclaim the extent when the extent is no longer referenced.

Hybrid garbage collection in a distributed storage system

In various embodiments, methods and systems for erasure coding with enhanced local protection groups are provided. An erasure coding scheme can be defined based on a Vertical Local Reconstruction Code (VLRC) that achieves high storage efficiency by combining the Local Reconstruction Code and conventional erasure coding, where the local reconstruction code (LRC) is carefully laid out across zones. Thus, when a zone is down, remaining fragments form an appropriate LRC. Further, an inter-zone erasure coding scheme&#x2014;Zone Local Reconstruction Code (ZZG-2 code)&#x2014;is provided having both local reconstruction within every zone and a-of-b recovery property across zones. An inter-zone adaptive erasure coding (uber code) scheme is provided, the uber code is configurable to produce near optimal performance in different environments characterized by intra and inter-zone bandwidth and machine failure rates. It is contemplated that embodiments described herein include functionality for recognizing correctable patterns and decoding techniques for coding schemes.

Flexible erasure coding with enhanced local protection group structures

In various embodiments, methods and systems for erasure coding data across multiple storage zones are provided. This may be accomplished by dividing a data chunk into a plurality of sub-fragments. Each of the plurality of sub-fragments is associated with a zone. Zones comprise buildings, data centers, and geographic regions providing a storage service. A plurality of reconstruction parities is computed. Each of the plurality of reconstruction parities computed using at least one sub-fragment from the plurality of sub-fragments. The plurality of reconstruction parities comprises at least one cross-zone parity. The at least one cross-zone parity is assigned to a parity zone. The cross-zone parity provides cross-zone reconstruction of a portion of the data chunk.

Erasure coding across multiple zones

Erasure coding across multiple zones and sub-zones

Cloud data storage systems, methods, and techniques partition system data symbols into predefined-sized groups and then encode each group to form corresponding parity symbols, encode all data symbols into global redundant symbols, and store each symbol (data, parity, and redundant) in different failure domains in a manner that ensures independence of failures. In several implementations, the resultant cloud-encoded data features both data locality and ability to recover up to a predefined threshold tolerance of simultaneous erasures (unavailable data symbols) without any information loss. In addition, certain implementations also feature the placement of cloud-encoded data in domains (nodes or node groups) to provide similar locality and redundancy features simultaneous with the recovery of an entire domain of data that is unavailable due to software or hardware upgrades or failures.

Cloud data storage using redundant encoding

Embodiments of the present invention relate to systems, methods and computer storage media for erasure coding data in a distributed computing environment. A sealed extent is identified that is comprised of two or more data blocks and two or more index blocks. The sealed extent is optimized for erasure coding by grouping the two or more data blocks within the optimized sealed extent together and grouping the two or more index blocks within the optimized sealed extent together. The optimized extent may also be erasure coded, which includes creating data fragments and coding fragments. The data fragments and the coding fragments may also be stored in the distributed computing environment. Additional embodiments include monitoring statistical information to determine if replication, erasure coding or a hybrid storage plan should be utilized.

Erasure coding immutable data

Systems, methods, and computer storage media for load balancing at a client device in a distributed computing environment based on a dynamic validity duration and utilization metrics of one or more data stores are provided. The client device selects a data store from a plurality of data stores that each maintains a copy of a datum. The selection of data stores by a client is based on utilization metrics of the data stores. The utilization metrics are stored at the client. A data store determines if a request for a particular datum may be fulfilled within a validity period associated with a request from the client. The validity period is dynamically changed by the client across multiple requests to aid in the load balancing process. Additionally, a gossip protocol may be used to propagate utilization metrics of a plurality of data stores across the system.

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Maple Valley, WA, United States of America

Huseyin Simitci