Release Notes for MongoDB 7.2
Important
MongoDB 7.2 is a rapid release and is only supported for MongoDB Atlas. MongoDB 7.2 is not supported for use on-premises. For more information, see MongoDB Versioning.
Patch Releases
7.2.2 - Feb 28, 2024
Issues Fixed:
SERVER-84723 Sharded multi-document transactions can observe partial effects of concurrent DDL operations
7.2.1 - Feb 27, 2024
Issues fixed:
SERVER-72703 Downgrade $out's db lock to MODE_IX
SERVER-80363 server default writeConcern is not honored when wtimeout is set
SERVER-83492 Remove limit and skip values from SBE plan cache key if possible
SERVER-84013 Incorrect results for index scan plan on query with duplicate predicates in nested $or
SERVER-84338 Top level $or queries may lead to invalid SBE plan cache entry which returns wrong results
7.2.0 - Jan, 9 2023
The rest of this page describes changes and new features introduced in MongoDB 7.2.
General Changes
Database Validation on mongos Aggregation Queries
Starting in MongoDB 7.2, aggregation pipeline queries that attempt to use non-existent databases on mongos deployments return validation errors.
In previous versions, these aggregation queries return empty cursors.
serverStatus Metrics
Starting in MongoDB 7.2, the serverStatus command and the
db.serverStatus() method outputs include the following new metrics:
getField Field Supports All Strings
Starting in MongoDB 7.2, you can specify any valid expression that resolves to a string for the field
input of the $getField operator. In earlier versions,
field accepts only string constants.
Default Chunks Per Shard
Starting in MongoDB 7.2, when you shard an empty collection with a hashed shard key, the operation creates one chunk per shard by default. Previously, the operation created two chunks by default.
Resharding Improvements
MongoDB 7.2 introduces significant performance improvements in reshard collection operations, substantially reducing the amount of time the operation takes to run.
Additionally, if your application and cluster meet the necessary
requirements and limitations, you can reshard the collection on the same key using
the reshardCollection command to redistribute your collection,
which is much faster than alternative range migration procedure.
The following options are added to the command:
Field | Description |
|---|---|
forceRedistribution | Enables same-key resharding. |
For examples, see Redistribute Data to New Shards.