US 11,080,262 B1 · Optimistic atomic multi-page write operations in decoupled multi-writer databases

Abstract

Systems and methods are disclosed to implement, in a database system, database engine nodes that implement multi-page writes as an atomic operation. In embodiments, the database system may include multiple database engine nodes that optimistically perform page writes locally without checking for potential conflicts at a shared storage system. The storage system will detect and report conflicting writes on a single page. To ensure that a group of writes to multiple pages occur atomically, the database engine node maintains a transaction context for the group, so that if a page conflict is later detected for any write in the group, the entire group will be rolled back at the database engine node and the storage system. In embodiments, the transaction context will track subsequent writes generated by the node to any page written by the group, so that these subsequent writes are also rolled back with the group.

Claims20

Dependent claims

A system, comprising:

one or more hardware processors with associated memory that implement a storage service configured to store pages of a database;
and
one or more hardware processors with associated memory that implement a plurality of database engine nodes configured to send requests to write the pages stored by the storage service, including a first database engine node configured to:
perform respective writes to different pages of the database in an in-memory data structure of the first database engine node, wherein the different pages are locked to atomically complete the writes;
send requests to the storage service to perform the respective writes on copies of the different pages stored by the storage service;
receive an indication of a conflict between one of the writes and a write, generated by a second database engine node of the database, committed to a copy of one of the different pages at the storage service;
responsive to receiving the indication of the conflict:
send one or more requests to the storage service to cancel the respective writes;
lock the different pages in the in-memory data structure to return the different pages to a state prior to the respective writes;
and
apply the write committed by the second database engine node to the one page in the in-memory data structure.

8 more elements

One or more non-transitory computer-accessible storage media storing program instructions that when executed on or across one or more processors implements a first writer of a plurality of writers of a database and cause the first writer to:

perform respective writes to different portions of an in-memory data structure for the database, wherein the different portions are locked to atomically complete the writes;
send requests to a data store that stores a copy of the in-memory data structure to perform the respective writes to the different portions in the copy;
receive an indication of a conflict between one of the writes and a write committed to one of the different portions of the copy of the in-memory data structure performed by a second writer to the database;
responsive to receiving the indication of the conflict:
send one or more requests to cancel the respective writes to the data store;
lock the different portions of the in-memory data structure to return the portions to a state prior to the respective writes;
and
apply the write committed to the one of the different portions of the copy of the in-memory data structure to the in-memory data structure.

5 more elements

Dependencies are inferred from the claim text.

Optimistic atomic multi-page write operations in decoupled multi-writer databases

Life of this patent

Optimistic atomic multi-page write operations in decoupled multi-writer databases

Life of this patent

Abstract

Claims20