MongoDB, Inc.
NON-BLOCKING SECONDARY READS

Abstract:

Described herein are embodiments of a database system. The database system receives a read command to read at least some stored data. The database system may generate a plurality of snapshots of data stored in a first data storage node of a plurality of data storage nodes. The database system may determine whether data is being written to the first data storage node. Responsive to determining that data is not being written to the first data storage node, the database system may process the read command at least in part by reading at least some data stored on the first data storage node. Responsive to determining that data is being written to the first data storage node, the database system may process the read command at least in part by reading at least some data from a snapshot of the plurality of snapshots.