公开(公告)号：US11327887B2

公开(公告)日：2022-05-10

申请号：US15705166

申请日：2017-09-14

Applicant: Oracle International Corporation

Inventor： Jia Shi ,  Wei Zhang ,  Kothanda Umamageswaran ,  Neil J. S. MacNaughton ,  Vijayakrishnan Nagarajan

IPC: G06F15/167 ,  G06F12/0808 ,  G06F13/28 ,  G06F16/10 ,  G06F16/172

Abstract: Techniques related to a server-side extension of client-side caches are provided. A storage server computer receives, from a database server computer, an eviction notification indicating that a data block has been evicted from the database server computer's cache. The storage server computer comprises a memory hierarchy including a volatile cache and a persistent cache. Upon receiving the eviction notification, the storage server computer retrieves the data block from the persistent cache and stores it in the volatile cache. When the storage server computer receives, from the database server computer, a request for the data block, the storage server computer retrieves the data block from the volatile cache. Furthermore, the storage server computer sends the data block to the database server computer, thereby causing the data block to be stored in the database server computer's cache. Still further, the storage server computer evicts the data block from the volatile cache.

公开(公告)号：US10387447B2

公开(公告)日：2019-08-20

申请号：US14823212

申请日：2015-08-11

Applicant: Oracle International Corporation

Inventor： Nilesh Choudhury ,  Scott Martin ,  Zuoyu Tao ,  Jia Shi ,  Alexander Tsukerman ,  Kothanda Umamageswaran

IPC: G06F16/27 ,  G06F11/14 ,  G06F3/06

Abstract: Techniques herein are for creating a database snapshot by creating a sparse database. A method involves receiving a creation request to create a sparse database. The creation request has an identity of a parent database. The creation request is processed to create a sparse database. The sparse database has the identity of the parent database. The sparse database does not contain data copied from the parent database. A write request to write data into the sparse database is received. The write request is processed by writing the data into the sparse database. The parent database does not receive the data.

公开(公告)号：US20190102113A1

公开(公告)日：2019-04-04

申请号：US15720959

申请日：2017-09-29

Applicant: Oracle International Corporation

Inventor： Nilesh Choudhury ,  Kothanda Umamageswaran ,  Krishnan Meiyyappan ,  Jia Shi ,  Vijay Sridharan ,  Zuoyu Tao ,  Kai Zhang ,  Semen Ustimenko ,  Salini Selvaraj Kowsalya ,  Somayeh Sardashti

IPC: G06F3/06 ,  G06F17/30

Abstract: A shared storage architecture persistently stores database files in non-volatile random access memories (NVRAMs) of computing nodes of a multi-node DBMS. The computing nodes of the multi-node DBMS not only collectively store database data on NVRAMs of the computing nodes, but also host database server instances that process queries in parallel, host database sessions and database processes, and together manage access to a database stored on the NVRAMs of the computing nodes. To perform a data block read operation from persistent storage, a data block may be transferred directly over a network between NVRAM of a computing node that persistently stores the data block to a database buffer in non-volatile RAM of another computing node that requests the data block. The transfer is accomplished using remote direct memory access (“RDMA).

公开(公告)号：US20250094385A1

公开(公告)日：2025-03-20

申请号：US18885394

申请日：2024-09-13

Applicant: Oracle International Corporation

Inventor： Nilesh Choudhury ,  Juan R. Loaiza ,  Kothanda Umamageswaran ,  Jia Shi ,  Vijay Sridharan ,  Alexander Tsukerman ,  Siddharth Choudhary

IPC: G06F16/13

Abstract: Herein is an accelerated interface between a database server and a storage area network (SAN). Persistent torage being managed for a database is spread across a number of storage buckets. Global distributed storage metadata is used only for tracking the location of storage buckets on different storage servers. With this approach, a very small amount of memory is needed at a global distributed level to maintain the map. Each storage bucket can have any number of mirrored replicas for further increasing speed and reliability. A database server contains a storage bucket map in memory, and uses the map to do database online transaction processing (OLTP) I/O and smart (i.e. offloaded) database operations on storage. This allows for direct I/O between database server and storage server with lower latency and without using slow and remote middleware such as a logical unit number (LUN) metadata server on a separate network element.

公开(公告)号：US11573719B2

公开(公告)日：2023-02-07

申请号：US16831337

申请日：2020-03-26

Applicant: Oracle International Corporation

Inventor： Wei Zhang ,  Jia Shi ,  Zuoyu Tao ,  Kothanda Umamageswaran

IPC: G06F3/06 ,  G06F12/1081 ,  G06F9/38 ,  G06F16/906

Abstract: Techniques are described for providing one or more clients with direct access to cached data blocks within a persistent memory cache on a storage server. In an embodiment, a storage server maintains a persistent memory cache comprising a plurality of cache lines, each of which represent an allocation unit of block-based storage. The storage server maintains an RDMA table that include a plurality of table entries, each of which maps a respective client to one or more cache lines and a remote access key. An RDMA access request to access a particular cache line is received from a storage server client. The storage server identifies access credentials for the client and determines whether the client has permission to perform the RDMA access on the particular cache line. Upon determining that the client has permissions, the cache line is accessed from the persistent memory cache and sent to the storage server client.

公开(公告)号：US10831666B2

公开(公告)日：2020-11-10

申请号：US16153674

申请日：2018-10-05

Applicant: Oracle International Corporation

Inventor： Jia Shi ,  Wei Zhang ,  Vijayakrishnan Nagarajan ,  Shih-Yu Huang ,  Kothanda Umamageswaran

IPC: G06F12/084 ,  G06F11/14 ,  G06F12/0897 ,  G06F16/2455

Abstract: Techniques related to failover to the secondary storage server from a primary storage server of a database server without degrading the performance of servicing storage requests for client applications are provided. In an embodiment, the secondary storage server receives, from the database server, an eviction notification indicating that a set of data blocks has been evicted from a cache. The secondary storage server's memory hierarchy includes a secondary cache and a secondary persistent storage that stores a second copy of the set of data blocks. The secondary storage server persistently stores a copy of data, which is also persistently stored on the primary storage server, which includes a first copy of the set of data blocks. In an embodiment, upon receiving the eviction notification, the secondary storage server retrieves the second copy of the set of data blocks from the secondary persistent storage of the secondary storage server and loads the second copy of the set of data blocks into the secondary cache. After an interruption event, the secondary storage receives a request for a subset of the set of data blocks based on a request for data, at the database server. Upon receiving the request for the subset of the set of data blocks, the second storage server retrieves the subset of the set of data blocks from the second copy of the set of data blocks stored on the secondary cache of the secondary storage server without retrieving any of such data blocks from the second copy of the set of data blocks stored on the persistent storage of the secondary storage server. The second storage server sends the subset of the set of data blocks to the database server.

公开(公告)号：US10732836B2

公开(公告)日：2020-08-04

申请号：US15720949

申请日：2017-09-29

Applicant: Oracle International Corporation

Inventor： Jia Shi ,  Yiliang Jin ,  Zheren R. Zhang ,  Zuoyu Tao ,  Vijay Sridharan ,  Kothanda Umamageswaran ,  Graham Ivey ,  Yunrui Li

IPC: G06F7/00 ,  G06F17/30 ,  G06F3/06 ,  G06F13/28 ,  G06F16/23 ,  G06F9/455 ,  G06F12/02 ,  G06F12/0871 ,  H04L29/08

Abstract: A shared storage architecture persistently stores database files in non-volatile random access memories (NVRAMs) of computing nodes of a multi-node DBMS. The computing nodes of the multi-node DBMS not only collectively store database data on NVRAMs of the computing nodes, but also host database server instances that process queries in parallel, host database sessions and database processes, and together manage access to a database stored on the NVRAMs of the computing nodes. To perform a data block read operation from persistent storage, a data block may be transferred directly over a network between NVRAM of a computing node that persistently stores the data block to a database buffer in non-volatile RAM of another computing node that requests the data block. The transfer is accomplished using remote direct memory access (“RDMA). In addition to techniques for performing a data block read operation to NVRAM, computing nodes perform a data block write operation to data blocks stored in NVRAM of the NVRAM shared storage architecture. The data block write operation is referred to herein as a one-sided write because only one database process needs to participate in the writing of a data block to NVRAM in order to successfully commit the write.

公开(公告)号：US10346362B2

公开(公告)日：2019-07-09

申请号：US14849012

申请日：2015-09-09

Applicant: Oracle International Corporation

Inventor： Zuoyo Tao ,  Nilesh Choudhury ,  Scott Martin ,  Mingmin Chen ,  Jia Shi ,  Alexander Tsukerman ,  Kothanda Umamageswaran

IPC: G06F16/174 ,  G06F17/30

Abstract: Techniques herein are for accessing non-materialized blocks of a sparse file. A method involves a storage system receiving a storage command to access a sparse file. A combined content of a set of materialized blocks and a header that identifies one or more non-materialized blocks is assembled. The combined content does not comprise a content of the one or more non-materialized blocks. Responsive to the assembling, the combined content is transferred between the storage system and a computer system.

公开(公告)号：US10331573B2

公开(公告)日：2019-06-25

申请号：US15687296

申请日：2017-08-25

Applicant: Oracle International Corporation

Inventor： Justin Matthew Lewis ,  Zuoyu Tao ,  Jia Shi ,  Kothanda Umamageswaran

IPC: G06F12/00 ,  G06F12/121 ,  G06F12/0891

Abstract: Techniques are provided to adjust the behavior of a cache based on a count of cache misses for items recently evicted. In an embodiment, a computer responds to evicting a particular item (PI) from a cache by storing a metadata entry for the PI into memory. In response to a cache miss for the PI, the computer detects whether or not the metadata entry for the PI resides in memory. When the metadata entry for the PI is detected in memory, the computer increments a victim hit counter (VHC) that may be used to calculate how much avoidable thrashing is the cache experiencing, which is how much thrashing would be reduced if the cache were expanded. Either immediately or arbitrarily later, the computer adjusts a policy of the cache based on the VHC's value. For example, the computer may adjust the capacity of the cache based on the VHC.

公开(公告)号：US20190102087A1

公开(公告)日：2019-04-04

申请号：US15720949

申请日：2017-09-29

Applicant: Oracle International Corporation

Inventor： Jia Shi ,  Yiliang Jin ,  Zheren R. Zhang ,  Zuoyu Tao ,  Vijay Sridharan ,  Kothanda Umamageswaran ,  Graham Ivey ,  Yunrui Li

IPC: G06F3/06 ,  G06F9/455 ,  G06F12/02 ,  G06F12/0871 ,  H04L29/08

Abstract: A shared storage architecture persistently stores database files in non-volatile random access memories (NVRAMs) of computing nodes of a multi-node DBMS. The computing nodes of the multi-node DBMS not only collectively store database data on NVRAMs of the computing nodes, but also host database server instances that process queries in parallel, host database sessions and database processes, and together manage access to a database stored on the NVRAMs of the computing nodes. To perform a data block read operation from persistent storage, a data block may be transferred directly over a network between NVRAM of a computing node that persistently stores the data block to a database buffer in non-volatile RAM of another computing node that requests the data block. The transfer is accomplished using remote direct memory access (“RDMA). In addition to techniques for performing a data block read operation to NVRAM, computing nodes perform a data block write operation to data blocks stored in NVRAM of the NVRAM shared storage architecture. The data block write operation is referred to herein as a one-sided write because only one database process needs to participate in the writing of a data block to NVRAM in order to successfully commit the write.