公开(公告)号：US20220318227A1

公开(公告)日：2022-10-06

申请号：US17218103

申请日：2021-03-30

Applicant: Dropbox, Inc.

Inventor： Preslav Le ,  Daniel Adkins ,  Braden Walker ,  Robert Escriva ,  Tanay Lathia ,  Alexander Sosa

IPC: G06F16/23 ,  G06F16/22

Abstract: A content management system stores distributed data tables containing key-value pairs across a plurality of nodes and maintains a plurality of slices, with each slice corresponding to a contiguous key range across the data tables. The content management system may rebalance data among nodes by performing operations such as transferring, merging, or splitting slices. Each operation may be accomplished by performing multiple actions, and each action may cause change in states for slices. During an operation, slices may go through a series of state transitions. For each state transition, the content management system may record a timestamp when the state transition took place and the content management system may maintain a log that records timestamped state transitions associated with slices. The content management system may also perform various invariant checks and determine whether to reject or allow a state transition based on results of invariant checks.

公开(公告)号：US11461365B2

公开(公告)日：2022-10-04

申请号：US16887714

申请日：2020-05-29

Applicant: Dropbox, Inc.

Inventor： Nipunn Koorapati ,  David Wetterau ,  Braden Walker ,  James Cowling ,  Sujay Jayakar

IPC: G06F16/30 ,  G06F16/27 ,  G06F16/11 ,  G06F16/18 ,  G06F16/178 ,  G06F16/176 ,  G06F3/06 ,  G06F21/60 ,  G06F21/62 ,  H04L9/40 ,  H04L67/06 ,  H04L67/1097 ,  G06F16/958 ,  G06F16/2455 ,  G06F16/951 ,  G06F16/172 ,  G06F1/04 ,  G06F9/54 ,  G06F11/14 ,  G06F12/14 ,  G06F21/10 ,  H04L9/32 ,  H04L67/1095 ,  G06F16/23 ,  G06F16/22 ,  G06F16/182 ,  G06F16/185 ,  G06F16/16 ,  G06F16/13 ,  G06F16/174 ,  G06F16/14 ,  G06F16/907 ,  G06F16/17 ,  G06F16/901 ,  G06F16/955 ,  H04L67/306 ,  H04L67/01

Abstract: A system can serialize moves and mounts across namespaces based on lamport clocks. In some examples, the system obtains a request to move a content item from a source namespace to a destination namespace. The system processes an incoming move at the destination and an outgoing move at the source. The system processes for the content item a delete at the source and an add at the destination. The system assigns a first clock to the incoming move and a second clock to the outgoing move, the first clock being lower than the second clock. The system assigns a third clock to the delete and a fourth clock to the add, the third clock being higher than the second clock and lower than the fourth clock. The system serializes the incoming and outgoing moves, the delete and the add based on the first, second, third and fourth clocks.

公开(公告)号：US20200293547A1

公开(公告)日：2020-09-17

申请号：US16887714

申请日：2020-05-29

Applicant: Dropbox, Inc.

Inventor： Nipunn Koorapati ,  David Wetterau ,  Braden Walker ,  James Cowling ,  Sujay Jayakar

IPC: G06F16/27 ,  G06F16/11 ,  G06F16/18 ,  G06F16/178 ,  G06F16/176 ,  G06F21/62 ,  G06F16/23 ,  G06F16/22 ,  H04L29/08 ,  G06F16/182 ,  G06F1/04 ,  G06F16/185 ,  H04L29/06 ,  G06F16/16 ,  G06F21/60 ,  G06F16/13 ,  G06F16/174 ,  G06F16/14 ,  G06F16/907 ,  G06F16/17 ,  G06F3/06 ,  G06F9/54 ,  G06F12/14 ,  G06F16/2455 ,  G06F16/172 ,  G06F11/14 ,  G06F21/10 ,  G06F16/958 ,  G06F16/901 ,  G06F16/951 ,  G06F16/955 ,  H04L9/32

Abstract: A system can serialize moves and mounts across namespaces based on lamport clocks. In some examples, the system obtains a request to move a content item from a source namespace to a destination namespace. The system processes an incoming move at the destination and an outgoing move at the source. The system processes for the content item a delete at the source and an add at the destination. The system assigns a first clock to the incoming move and a second clock to the outgoing move, the first clock being lower than the second clock. The system assigns a third clock to the delete and a fourth clock to the add, the third clock being higher than the second clock and lower than the fourth clock. The system serializes the incoming and outgoing moves, the delete and the add based on the first, second, third and fourth clocks.

公开(公告)号：US12050591B2

公开(公告)日：2024-07-30

申请号：US18354626

申请日：2023-07-18

Applicant: Dropbox, Inc.

Inventor： Preslav Le ,  Braden Walker ,  Leslie Tu ,  Tanay Lathia ,  Alexander Sosa ,  Lihao He

IPC: G06F16/23 ,  G06F16/22

CPC classification number: G06F16/2365 ,  G06F16/2272

Abstract: A consistency verification system that verifies data consistency in a content item management system. The system processes a write request. The write request includes a set of preconditions, a key, and data to write in a write operation. Processing the write request includes determining that the set of conditions are met, committing the write request at a commit time, and assigning a timestamp indicating the commit time to the write request. The system verifies data consistency associated with the write request. The verifying data consistency includes sending a replay request corresponding to the write request. The system determines whether results of the replay are consistent with results of the write request. Responsive to determining whether results of the replay are consistent with results of the write request, the system outputs information describing data inconsistency.

公开(公告)号：US11914727B2

公开(公告)日：2024-02-27

申请号：US17129337

申请日：2020-12-21

Applicant: Dropbox, Inc.

Inventor： Aaron Passey ,  Braden Walker ,  Akos Albert

IPC: G06F21/62 ,  G06F16/2455 ,  G06F16/901

CPC classification number: G06F21/6209 ,  G06F16/24566 ,  G06F16/9017

Abstract: The disclosed technology addresses the need in the art for a content management system that can be highly flexible to the needs of its subjects. The present technology permits any object to be shared by providing a robust and flexible access control list mechanism. The present technology utilizes a data structure that is highly efficient that both minimizes the amount of information that needs to be written into any database, but also allows for fast reads and writes of information from authoritative tables that are a source of truth for the content management system, while allowing for maintenance of indexes containing more refined data that allow for efficient retrieval of certain information that would normally need to be calculated when it is needed.

公开(公告)号：US20230004550A1

公开(公告)日：2023-01-05

申请号：US17364606

申请日：2021-06-30

Applicant: Dropbox, Inc.

Inventor： Preslav Le ,  Braden Walker ,  Leslie Tu ,  Tanay Lathia ,  Alexander Sosa ,  Lihao He

IPC: G06F16/23 ,  G06F16/22

Abstract: A consistency verification system that verifies data consistency in a content item management system. The system maintains a plurality of verifiers for checking data consistency, each verifier comprising instructions for verifying consistency for a type of requests. The system may verify the original request by selecting a verifier from the plurality of verifiers based on a type of the original request. Using the selected verifier, the consistency verification system may send verification requests to the content item management system at a second timestamp that is a period of time after the original timestamp. The system may determine whether the second response is consistent with the first response. If the responses are not consistent, the system may output information describing data inconsistency. If the responses are consistent, the system may output results and perform further verifications to help ensure data accuracy.

公开(公告)号：US11474977B2

公开(公告)日：2022-10-18

申请号：US16588960

申请日：2019-09-30

Applicant: DROPBOX, INC.

Inventor： David Wetterau ,  Braden Walker

IPC: G06F16/18 ,  G06F16/182 ,  G06F11/14 ,  G06F16/14

Abstract: Systems and methods for snapshot isolation in a distributed storage system M are provided. In some examples, a method can include receiving a request for data from a data store comprising a plurality of storage nodes, the request comprising a key associated with the data and a request timestamp, identifying a storage node in the plurality of storage nodes from which to read the data based on the key and a mapping of keys to storage nodes, determining that the request is associated with a transaction comprising operations associated with at least one other storage node in the plurality of storage nodes, determining a status of the entry for the key in the key-value table based on a lookup of a transaction table using the transaction identifier, and providing the data when the status of the entry for the key indicates the data is ready to be read.

公开(公告)号：US20220197883A1

公开(公告)日：2022-06-23

申请号：US17129292

申请日：2020-12-21

Applicant: Dropbox, Inc.

Inventor： Aaron Passey ,  Braden Walker ,  Akos Albert

IPC: G06F16/22 ,  G06F16/23

Abstract: The disclosed technology addresses the need in the art for a content management system that can be highly flexible to the needs of its subjects. The present technology permits any object to be shared by providing a robust and flexible access control list mechanism. The present technology utilizes a data structure that is highly efficient that both minimizes the amount of information that needs to be written into any database, but also allows for fast reads and writes of information from authoritative tables that are a source of truth for the content management system, while allowing for maintenance of indexes containing more refined data that allow for efficient retrieval of certain information that would normally need to be calculated when it is needed.

公开(公告)号：US20210097036A1

公开(公告)日：2021-04-01

申请号：US16588960

申请日：2019-09-30

Applicant: DROPBOX, INC.

Inventor： David Wetterau ,  Braden Walker

IPC: G06F16/18 ,  G06F16/182 ,  G06F16/14 ,  G06F11/14

Abstract: Systems and methods for snapshot isolation in a distributed storage system M are provided. In some examples, a method can include receiving a request for data from a data store comprising a plurality of storage nodes, the request comprising a key associated with the data and a request timestamp, identifying a storage node in the plurality of storage nodes from which to read the data based on the key and a mapping of keys to storage nodes, determining that the request is associated with a transaction comprising operations associated with at least one other storage node in the plurality of storage nodes, determining a status of the entry for the key in the key-value table based on a lookup of a transaction table using the transaction identifier, and providing the data when the status of the entry for the key indicates the data is ready to be read.

公开(公告)号：US20240330259A1

公开(公告)日：2024-10-03

申请号：US18738249

申请日：2024-06-10

Applicant: Dropbox, Inc.

Inventor： Aaron Passey ,  Braden Walker ,  Akos Albert

IPC: G06F16/21 ,  G06F16/27

CPC classification number: G06F16/219 ,  G06F16/27 ,  G06F16/273 ,  G06F16/275 ,  G06F16/278

Abstract: The disclosed technology addresses the need in the art for a content management system that can be highly flexible to the needs of its subjects. The present technology permits any object to be shared by providing a robust and flexible access control list mechanism. The present technology utilizes a data structure that is highly efficient that both minimizes the amount of information that needs to be written into any database, but also allows for fast reads and writes of information from authoritative tables that are a source of truth for the content management system, while allowing for maintenance of indexes containing more refined data that allow for efficient retrieval of certain information that would normally need to be calculated when it is needed.