公开(公告)号：US20230123478A1

公开(公告)日：2023-04-20

申请号：US17504845

申请日：2021-10-19

Applicant: VMware, Inc.

Inventor： Enning XIANG ,  Wenguang WANG ,  Abhay Kumar JAIN ,  Sriram PATIL ,  Asit DESAI ,  Eric KNAUFT

IPC: G06F16/11 ,  G06F16/182 ,  G06F16/22 ,  G06F12/02

Abstract: Example methods and systems for accessing data in a log-structured file system having a plurality of snapshots of storage objects backed by a first-level copy-on-write (COW) B+ tree data structure and a plurality of second-level B+ tree data structures have been disclosed. One example method includes obtaining a first first-level mapping associated with a first snapshot from the plurality of snapshots based on a first logical block address, wherein each of the plurality of snapshots corresponds to each of the plurality of second-level B+ tree data structures, identifying a first second-level B+ tree data structure corresponding to one of the plurality of snapshots based on the first first-level mapping, obtaining a first second-level mapping based on the first logical block address in the first second-level B+ tree data structure, obtaining a first physical block address based on the first second-level mapping, and accessing data at the first physical block address.

公开(公告)号：US20220407685A1

公开(公告)日：2022-12-22

申请号：US17402293

申请日：2021-08-13

Applicant: VMware, Inc.

Inventor： Tao XIE ,  Wenguang WANG ,  Ruiling DOU ,  Zhao JIN

IPC: H04L9/08 ,  H04L29/08

Abstract: A method for encryption in a distributed datastore is provided. The method generally includes receiving random data from a virtualization management platform as a wrapped data encryption key (DEK), retrieving a key encryption key (KEK) from a key management server (KMS), decrypting the wrapped DEK using the KEK to determine a blank DEK, where the blank DEK is common to a plurality of hosts of a host cluster accessing a distributed datastore; encrypting first data using the blank DEK, and storing the encrypted first data in one or more disks of the distributed datastore, the one or more disks belonging to the plurality of hosts.

公开(公告)号：US20220261386A1

公开(公告)日：2022-08-18

申请号：US17177686

申请日：2021-02-17

Applicant: VMware, Inc.

Inventor： Hardik Singh NEGI ,  Wenguang WANG ,  Eric KNAUFT

IPC: G06F16/22 ,  G06F16/23 ,  G06F16/2455 ,  G06F16/28

Abstract: A method for modifying key-value pairs of a B+ tree is provided. The method receives a request to modify a particular key-value pair. Each node of the tree has a modification number. The method traverses a path on the tree from the root node toward the particular node. The traversing includes upon reaching a parent node of the path, acquiring a shared lock on both the parent node and a child node one level below the parent node. Upon determining that the child node is the particular node, the method stores the modification number of the particular node, releases the shared lock on the particular node, compares a current modification number of the node with its stored number, and acquires an exclusive lock on the node if the numbers are the same. The method increments the current modification number of the node and modifies it while in the exclusive lock.

公开(公告)号：US20220121532A1

公开(公告)日：2022-04-21

申请号：US17072961

申请日：2020-10-16

Applicant: VMware, Inc.

Inventor： Petr VANDROVEC ,  Wenguang WANG ,  Vamsidhar GUNTURU ,  Junlong GAO ,  Ilia SOKOLINSKI ,  Maxime AUSTRUY

IPC: G06F11/14

Abstract: Techniques for the increased efficiency of storing data objects storage in the object storage of a software designed data center (SDDC) are provided. The techniques include the efficient storage of data, while enabling snapshots of each updating of the data. The snapshots of the data may be efficiently recovered via the techniques. Difference-level mappings for each snapshot are encoded in compact self-balancing data trees included in the object's metadata. The metadata mappings include mappings between various address spaces employed by the SDDC, as well as the address spaces employed by data stores that store the data on physical medium. Because the metadata is efficiently structured, the metadata for an object may be cached for quick lookups during data access and/or snapshot recovery. The techniques also provide low-latency recovery and/or system rollback in the event of any failure in the SDDC, including when the failure occurs while uploading a snapshot.

公开(公告)号：US20210349791A1

公开(公告)日：2021-11-11

申请号：US16870852

申请日：2020-05-08

Applicant: VMware, Inc.

Inventor： Wenguang WANG ,  Vamsi GUNTURU ,  Eric KNAUFT

IPC: G06F11/14 ,  G06F3/06

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for resynchronizing data in a storage system. One of the methods includes receiving, by a first storage subsystem, a plurality of write requests corresponding to respective meta data blocks, wherein the first storage subsystem comprises a meta object; storing, by the first storage subsystem and for each write request, in each disk of the meta object, a version of the corresponding meta data block; determining that a particular disk of the meta object has failed; determining whether one or more valid versions of the meta data block are stored in respective other disks of the meta object; and in response to determining that one or more valid versions of the meta data block are stored in respective other disks of the meta object, resynchronizing the meta data block in the particular disk.

公开(公告)号：US20210334178A1

公开(公告)日：2021-10-28

申请号：US16859944

申请日：2020-04-27

Applicant: VMware, Inc.

Inventor： Yang YANG ,  Ye ZHANG ,  Xiang YU ,  Wenguang WANG ,  Richard P. SPILLANE ,  Sriram PATIL

IPC: G06F11/20 ,  G06F11/30 ,  G06F11/34 ,  G06F16/17 ,  G06F9/455

Abstract: System and method for automatic remediation for a distributed file system uses a file system (FS) remediation module running in a cluster management server and FS remediation agents running in a cluster of host computers. The FS remediation module monitors the cluster of host computers for related events. When a first file system service (FSS)-impacting event is detected, a cluster-level remediation action is executed at the cluster management server by the FS remediation module in response to the detected first FSS-impacting event. When a second FSS-impacting event is detected, a host-level remediation action is executed at one or more of the host computers in the cluster by the FS remediation agents in response to the detected second FSS-impacting event.

公开(公告)号：US20210141728A1

公开(公告)日：2021-05-13

申请号：US16679570

申请日：2019-11-11

Applicant: VMware, Inc.

Inventor： Wenguang WANG ,  Mounesh BADIGER ,  Abhay Kumar JAIN ,  Junlong GAO ,  Zhaohui GUO ,  Richard P. SPILLANE

IPC: G06F12/0842 ,  G06F12/0844 ,  G06F12/0871 ,  G06F12/1018 ,  G06F12/14

Abstract: Disclosed are a method and system for managing multi-threaded concurrent access to a cache data structure. The cache data structure includes a hash table and three queues. The hash table includes a list of elements for each hash bucket with each hash bucket containing a mutex object and elements in each of the queues containing lock objects. Multiple threads can each lock a different hash bucket to have access to the list, and multiple threads can each lock a different element in the queues. The locks permit highly concurrent access to the cache data structure without conflict. Also, atomic operations are used to obtain pointers to elements in the queues so that a thread can safely advance each pointer. Race conditions that are encountered with locking an element in the queues or entering an element into the hash table are detected, and the operation encountering the race condition is retried.

公开(公告)号：US20200242034A1

公开(公告)日：2020-07-30

申请号：US16256726

申请日：2019-01-24

Applicant: VMware, Inc.

Inventor： Wenguang WANG ,  Christoph KLEE ,  Adrian DRZEWIECKI ,  Christos KARAMANOLIS ,  Richard P. SPILLANE ,  Maxime AUSTRUY

IPC: G06F12/0815 ,  G06F12/1027

Abstract: The present disclosure provides techniques for managing a cache of a computer system using a cache management data structure. The cache management data structure includes a cold queue, a ghost queue, and a hot queue. The techniques herein improve the functioning of the computer because management of the cache management data structure can be performed in parallel with multiple cores or multiple processors, because a sequential scan will only pollute (i.e., add unimportant memory pages) cold queue, and to an extent, ghost queue, but not hot queue, and also because the cache management data structure has lower memory requirements and lower CPU overhead on cache hit than some prior art algorithms.

公开(公告)号：US20200241939A1

公开(公告)日：2020-07-30

申请号：US16256713

申请日：2019-01-24

Applicant: VMware, Inc.

Inventor： Wenguang WANG ,  Christoph KLEE ,  Adrian DRZEWIECKI ,  Christos KARAMANOLIS ,  Richard P. SPILLANE ,  Maxime AUSTRUY

IPC: G06F9/54

Abstract: The disclosure provides an approach for performing an operation by a first process on behalf of a second process, the method comprising: obtaining, by the first process, a memory handle from the second process, wherein the memory handle allows access, by the first process, to at least some of the address space of the second process; dividing the address space of the memory handle into a plurality of sections; receiving, by the first process, a request from the second process to perform an operation; determining, by the first process, a section of the plurality of sections that is to be mapped from the address space of the memory handle to the address space of the first process for the performance of the operation by the first process; mapping the section from the address space of the memory handle to the address space of the first process; and performing the operation by the first process on behalf of the second process.

公开(公告)号：US20190294715A1

公开(公告)日：2019-09-26

申请号：US15927030

申请日：2018-03-20

Applicant: VMware, Inc.

Inventor： Abhishek GUPTA ,  Rob T. JOHNSON ,  Srinath PREMACHANDRAN ,  Richard P. SPILLANE ,  Sandeep RANGASWAMY ,  Jorge GUERRA DELGADO ,  Kapil CHOWKSEY ,  Wenguang WANG

IPC: G06F17/30 ,  G06F9/54

Abstract: Exemplary methods, apparatuses, and systems include a file system process obtaining locks on a first node and a second node in a tree structure, with the second node being a child node of the first node. The file system process determines a quantity of child nodes of the second. While holding the locks on the first and second nodes, the file system determines whether to proactively split or merge the second node. In response to determining that the quantity of child nodes is within a first range, the file system process splits the second node. If the file system process determines that the quantity of child nodes is within a second range, the file system process merges the second node.