What’s new in 3.5

• CMAP-compliant connection pool
• Dedicated monitoring connection
• Server selection error improvements

Full 3.5 Changes Here

What’s new in 3.4

• MongoDB Client Side Field Level Encryption

Full 3.4 Changes Here

What’s new in 3.3

• Supports Distributed Transactions
• Supports On-Demand Materialized Views with the $merge operator
• Supports Wildcard Indexes
• Supports Retryable Reads
• Supports MongoDB Query Language Enhancements.
• SRV Polling for Sharded Clusters
• Beta support for MongoDB Client-Side Encryption

Full 3.3 Changes Here

What’s new in 3.2

• Supports new “Unified Topology” for resolving servers (opt in with useUnifiedTopology option for MongoClient)
• Supports session.withTransaction helper
• Supports Asynchronous Iteration (for await... syntax) on cursors
• Supports Database-level Aggregations (db.aggregate(pipeline, options))

Full 3.2 Changes Here

What’s new in 3.1

• Support for MongoDB version 4.0
• Support for Transactions
• Support for authentication with SCRAM-SHA-256
• Support for new URL parser (opt in with useNewUrlParser option for MongoClient)

Full 3.1 Changes Here

What’s new in 3.0

• Support added for Retryable Writes
• Support added for DNS Seedlists
• Support added for Change Streams
• Support added for sessions
• MongoClient.connect now returns a Client instead of a DB.

Full 3.0 Changes Here

What’s New in 2.3

Key features of the 2.3 driver include:

• Implements Decimal128, a decimal floating-point numbering format that occupies 16 bytes (128 bits). See the CRUD tutorial for an example.

What’s New in 2.2

Key features of the 2.2 driver include:

• Redesigned Connection Pool.
• Connection close will drain any outstanding operations.
• replicaSet parameter MUST be specified if using MongoClient to connect to replicaset, due to SDAM specification implementation.
• Domain support disabled by default, enable with parameter domainsEnabled on MongoClient or on the Server/ReplSet/Mongos.

What’s New in 2.1

Key features of the 2.1 driver include:

• Implements the new GridFS specification
• Implements support for the new 3.2 wire protocol level find, getMore and killCursor commands
• A growing/shrinking connection pool
• A worker-based connection pool which minimizes the impact of slow operations on throughput and latency when the number of slow operations is less than the number of connections in the pool
• Topology monitoring specification implementation, allowing applications to monitor the view of the topology as it changes

What’s New in 2.0

Key features of the 2.0 driver include:

• Adherence to the SDAM (Server Discovery and Monitoring Specification)
• Implementation of the CRUD Specification
• Performance improvements
• New JS-BSON parser which replaces the C++ extension
• A new core driver on top of which you can build alternative or experimental driver APIs
• APM (Application Performance Monitoring) API

Driver revision history.

Upgrading

See the 3.0 Changes on how to upgrade to 3.0 See the upgrading guide on how to upgrade to 2.0