Release Highlights

This release includes a number of features we’re happy to announce. You can now run aggregation pipelines that write write to a MongoDB collection using $out and $merge stages on secondaries! We’ve added an option to limit the number of hosts the driver will connect to when using SRV DNS lookups to manage your host addresses. And lastly, the authorizedCollection option is now usable on the db.listCollections() function.

Additionally, in this release, we’ve marked collection.mapReduce() as deprecated. The same functionality can be replicated in the much more flexible aggregation pipeline. Visit Map-Reduce to Aggregation Pipeline to learn more.

The minimum supported MongoDB version is 3.6. Attempts to connect to a MongoDB server older than 3.6 will result in an error. Please take note of the MongoDB Software Lifecycle Schedules for timeframes of supported server versions.

Features

• NODE-3083: support aggregate writes on secondaries (#3022) (f696909)
• NODE-3446: deprecate mapReduce command (#3036) (b6c73bf)
• NODE-3467: implement srvMaxHosts, srvServiceName options (#3031) (1f8b539)
• NODE-3469,NODE-3615,NODE-3507: update min and max wire versions (#3014) (2a78d5a)
• NODE-3691: make time series options granularity type strict (#3005) (98017f9)
• NODE-3692: make change stream events typing more generic (#3034) (d5ae78e)
• NODE-3728: Allow to pass authorizedCollections option to the db.listCollections method (#3021) (e1234a7)
• NODE-3729: add withId to default return type for collection.find and collection.findOne (#3039) (52520aa)

Bug Fixes

• NODE-3116: reschedule unreliable async interval first (#3006) (33886a7)
• NODE-3344: allow setting defaultTransactionOptions with POJO rather than ReadConcern instance (#3032) (53b3164)
• NODE-3515: do proper opTime merging in bulk results (#3012) (43300c3)
• NODE-3668: compile error with OptionalId on TS 4.5 beta (#3004) (ee7f095)
• NODE-3726: add optional option overloads of Db's createCollection function (#3019) (c3149e1)
• NODE-3727: add overloads for BulkOperationBase's execute function (#3018) (216d194)

Documentation

• Reference: https://docs.mongodb.com/drivers/node
• API: https://mongodb.github.io/node-mongodb-native/4.2
• Changelog: https://github.com/mongodb/node-mongodb-native/blob/main/HISTORY.md

We invite you to try the mongodb library immediately, and report any issues to the NODE project.

Release Highlights

This release includes a couple of bug fixes as noted below:

Bug Fixes

• NODE-3515: do proper opTime merging in bulk results (#3012) (43300c3)
• NODE-3668: compile error with OptionalId on TS 4.5 beta (#3004) (ee7f095)

Documentation

• Reference: https://docs.mongodb.com/drivers/node
• API: https://mongodb.github.io/node-mongodb-native/4.1
• Changelog: https://github.com/mongodb/node-mongodb-native/blob/4.1/HISTORY.md

We invite you to try the mongodb library immediately, and report any issues to the NODE project.

The MongoDB Node.js team is pleased to announce version 4.1.3 of the mongodb package!

Release Highlights

This release includes a couple of TypeScript fixes as noted below:

Bug Fixes

• NODE-3609: correct listDatabases return type (#2986) (a8e9938)
• NODE-3624: Incorrect default aggregation generic type (#2987) (440517e)

Documentation

• Reference: https://docs.mongodb.com/drivers/node
• API: https://mongodb.github.io/node-mongodb-native/4.1
• Changelog: https://github.com/mongodb/node-mongodb-native/blob/4.1/HISTORY.md

We invite you to try the mongodb library immediately, and report any issues to the NODE project.

The MongoDB Node.js team is pleased to announce version 4.1.2 of the mongodb package!

Release Highlights

This release addresses a number of bug fixes, please peruse the list below for more information on each fix.

Bug Fixes

• NODE-3434: errInfo should be exposed on bulk write (#2977) (6b3c161)
• NODE-3467: allow object type for aggregate out helper (#2971) (cd603e8)
• NODE-3487: check for nullish aws mechanism property (#2951) (78ec0dd)
• NODE-3559: incorrect GridFS stream type (#2981) (3915ea8)
• NODE-3567: correct typing on aggregation out helper (#2967) (a299a0b)
• NODE-3574: reintroduce ObjectID export (#2965) (2291119)
• NODE-3585: MongoClientOptions#compressors has incorrect type (#2976) (f1b896d)
• NODE-3591: tlsCertificateKeyFile option does not default cert (#2979) (6d42267)
• NODE-3599: incorrect indexes return type (#2980) (122b9f3)

Documentation

• Reference: https://docs.mongodb.com/drivers/node
• API: https://mongodb.github.io/node-mongodb-native/4.1
• Changelog: https://github.com/mongodb/node-mongodb-native/blob/4.1/HISTORY.md

We invite you to try the mongodb library immediately, and report any issues to the NODE project.

The MongoDB Node.js team is pleased to announce version 4.1.1 of the mongodb package!

Release Highlights

Error handling

We introduced better organization and consistency to our existing errors in an effort to provide more detailed error types that can help identify issues clearly and quickly. Our readme has a new section that describes how to handle errors thrown by the driver and defines our approach to semver in the context of errors. Notably, we recommend only using instanceof checks to filter for a given error class as we do not guarantee error messages or names will be preserved between patch releases, only the subclass hierarchy.

Thanks so much to our summer interns @andymina and @W-A-James for undertaking this effort!

Notable fixes

• This version of the driver brings in the latest BSON release which includes deserialization performance improvements.
• The snappy package recently released a major version bump (v7) that makes use of a rust implementation of Snappy compression. Our driver can now make use of this version (while maintaining compatibility with the previous v6).
• findOne() once again correctly returns null when no match is found instead of undefined. This change was unintentional and not consistent with our other APIs. It slipped through testing due to the nature of undefined and null being nearly (==) but not actually (===) equal. We apologize if this results in the need for any code changes.

This release also addresses some Typescript issues that require further explanation, let's dive in:

TypeScript support

Projections

Starting in MongoDB 4.4 projections can accept aggregation expressions and aggregation syntax. This empowers users to create some pretty amazing and complex data model transformations on the database side. Unfortunately, our initial release of typescript typing for projections was too narrow to allow these use cases and still pass the compiler checks. Now projections are generic objects and the result of a cursor with a projection is typed as a generic object by default.

The recommended usage for projections alongside typescript is as follows:

interface Pet {
    name: string;
    buddies: Pet[];
}
interface PetBuddyCount {
    name: string;
    buddyCount: number;
}

const pets = db.collection<Pet>('pets');

const petBuddyCounts = await pets.find().project<PetBuddyCount>({
    name: 1,
    buddyCount: { $size: '$buddies' },
}).toArray();

By using a parameterized .project call you can now get the correct type information on the petBuddyCounts array. You will need to build the projection type yourself based on the projection you define for your query, but this has the benefit of constraining your results to precisely your type expectations.

Generics in find/findOne

In our initial typescript release the find and findOne methods accepted a generic parameter that was passed to the filter argument of the API.

find<T>(f: Filter<T>): FindCursor<T>

Due to how typescript automatically resolves the types of generics, one could run into an issue when specifying a filter that was incorrectly typed. The code below should be a Typescript error, TS hints to us the name is a string so it should only allow an array of string for $in.

// (using the same pets collection from the last example)
pets.find({ name: { $in: [1, 2] } });
// instead of the expected FindCursor<Pet> type TS was resolving to:
const res: FindCursor<{name: {$in: number[]}}> = pets.find(/* same arg as above */);

It uses the incorrectly typed filter that does not match the schema of Filter<TSchema> to automatically resolve a crazy return type. The function definition has now been updated to be:

find<T>(f: Filter<TSchema>): FindCursor<T>

So the Filter argument will no longer be automatically resolved to the passed in type, giving us the typescript compiler errors we love so much!

Bug Fixes

• NODE-3454: projection types are too narrow (#2924) (48d6da9)
• NODE-3468: remove generic overrides from find (#2935) (74bd7bd)
• NODE-3511: deprecate fullResponse and remove associated buggy code paths (#2943) (dfc39d1)
• NODE-3528: add support for snappy 7 (#2939) (0f7f300)
• NODE-3546: revert findOne not found result type to null (#2945) (1c576e9)

Refactoring

• NODE-3404 implement MongoRuntimeError children (#2912) (e69d99257)
• NODE-3405 implement MongoRuntimeError children (#2913) (e69d99257)

Documentation

• Reference: https://docs.mongodb.com/drivers/node
• API: https://mongodb.github.io/node-mongodb-native/4.0
• Changelog: https://github.com/mongodb/node-mongodb-native/blob/4.1/HISTORY.md

We invite you to try the mongodb library immediately, and report any issues to the NODE project.

The MongoDB Node.js team is pleased to announce version 4.1.0 of the mongodb package!

Release Highlights

This release includes load balancer support, intended for use with the beta Serverless platform. When using the driver with Serverless, the SRV URI will automatically put the driver into this mode. When wanting to use a non-SRV URI one must add the loadBalanced=true option to the URI to put the driver into this mode. Being in this mode enables the driver to properly route transactions and cursors to the correct service behind the load balancer.

The release also fixes an important bug where the original release of the v4 driver enabled command monitoring by default, which caused many reported observations of performance degradation when upgrading from v3 of the driver. Command monitoring is now once again disabled by default and must be enabled by passing in { monitorCommands: true } to the client if desired.

Features

• NODE-2843: implement sessions advanceClusterTime method (#2920) (1fd0244)
• NODE-3011: Load Balancer Support (#2909) (c554a7a)

Bug Fixes

• NODE-2883: Aggregate Operation should not require parent parameter (#2918) (dc6e2d6)
• NODE-3058: accept null or undefined anywhere we permit nullish values (#2921) (b42a1b4)
• NODE-3441: fix typings for createIndexes (#2915) (f87f376)
• NODE-3442: AsyncIterator has incorrect return type (#2916) (4a10389)
• NODE-3452: readonly filters not permitted by typings (#2927) (ce51e78)
• NODE-3510: omit incorrect | void in declaration of Promise overload of rename() (#2922) (58c1e84)
• NODE-3513: default command monitoring to off (#2926) (3c60245)

Documentation

• Reference: https://docs.mongodb.com/drivers/node
• API: https://mongodb.github.io/node-mongodb-native/4.0
• Changelog: https://github.com/mongodb/node-mongodb-native/blob/4.0/HISTORY.md

We invite you to try the mongodb library immediately, and report any issues to the NODE project.

The MongoDB Node.js team is pleased to announce version 4.0.1 of the mongodb package!

Release Highlights

This release fixes two small but important bugs from our 4.0.0 release:

• Webpack will no longer throw an error when trying to bundle the driver
• Snapshot sessions will now correctly apply the snapshot time when initiated with a distinct operation

We hope this improves your upgrade experience!

Bug Fixes

• NODE-3199: unable to bundle driver due to uncaught require (#2904) (9e48bbd)
• NODE-3393: snapshot time not applied if distinct executed first (#2908) (7aa3008)
• NODE-3417: allow calling db() before MongoClient is connected (#2889) (51ea86d)

Documentation

• Reference: https://docs.mongodb.com/drivers/node
• API: https://mongodb.github.io/node-mongodb-native/4.0
• Changelog: https://github.com/mongodb/node-mongodb-native/blob/4.0/HISTORY.md

We invite you to try the mongodb library immediately, and report any issues to the NODE project.

The MongoDB Node.js team is delighted to announce the major version release 4.0.0 of the MongoDB Node.js Driver!

Release Highlights

We finally did it! The major version release of the MongoDB driver is now generally available! This release represents over a year's worth of effort that couldn't have been done without stellar contributions from the community and our Node.js DBX team. We hope you give it a try and are able to upgrade smoothly! :tada:

The biggest news is our migration to Typescript :partying_face: offering first class support of type definitions in the driver itself.

Some cool new MongoDB 5.0 features now supported in the driver are:

• Native support for Time Series Collections
  • Time series collections efficiently store sequences of measurements over a period of time. Compared to normal collections, storing time series data in time series collections improves query efficiency and reduces the disk usage for time series data and secondary indexes
• Snapshot reads on secondaries
  • Support for read concern level "snapshot" (non-speculative) for read commands outside of transactions, including on secondaries. The snapshot reads on secondaries feature allows users to perform analytics with snapshot isolation on dedicated secondaries, including long running snapshot reads.

Below are only the changes since our last beta release, for the full set of breaking changes look at the upgrade guide here and for the full set of new features, take a look here.

⚠ BREAKING CHANGES (since beta.6)

• NODE-3427: remove md5 hashing from GridFS API (#2899) (a488d88)
• NODE-1797: error when ChangeStream used as iterator and emitter concurrently (#2871) (e0b3afe)
• AND MORE!

Features (since beta.6)

• NODE-3095: add timeseries options to db.createCollection (#2878) (c145c91)
• NODE-3392: enable snapshot reads on secondaries (#2897) (523e05c)
• NODE-3403: define MongoRuntimeError children (#2894) (cb0db49)
• NODE-3410: added MongoRuntimeError (#2892) (ee903cb)
• AND MORE!

Bug Fixes

• NODE-1797: error when ChangeStream used as iterator and emitter concurrently (#2871) (e0b3afe)
• NODE-1843: bulk operations ignoring provided sessions (#2868) (70810d1)
• NODE-3063: fix custom csfle test script (#2884) (d73c80c)
• NODE-3279: use "hello" for monitoring if supported (#2895) (5a8842a)
• NODE-3386: listCollections result type definition (#2866) (c12979a)
• NODE-3413: accept tls=false in mongodb+srv connection strings (#2886) (526c73f)
• NODE-3416: make change stream generic default to Document (#2882) (3d490dc)
• NODE-3430: watch method types on MongoClient and Db (#2900) (17cc291)

Documentation

• Reference: https://docs.mongodb.com/drivers/node
• API: https://mongodb.github.io/node-mongodb-native/4.0
• Changelog: https://github.com/mongodb/node-mongodb-native/blob/4.0/HISTORY.md

We invite you to try the mongodb library immediately, and report any issues to the NODE project.

The MongoDB Node.js team is pleased to announce version 4.0.0-beta.6 of the mongodb package!

Release Highlights

This is on the larger side of the beta releases we've done so far we're getting closer to calling this version official.

As a breaking change in this release we now make use of the new MongoDriverError and MongoServerError to clarify where the issue arose from. All of the errors that our driver throws subclass from MongoError so its possible to filter in catch blocks using instanceof. Take a look at this example:

// without calling .connect()
await c.insertOne({ a: 1 })
// Uncaught MongoDriverError: MongoClient must be connected before calling MongoClient.prototype.db
//   at MongoClient.db (lib/mongo_client.js)
await c.insertOne({ _id: /a/ })
// Uncaught MongoServerError: can't use a regex for _id
//   at lib/operations/insert.js {
//     index: 0,
//     code: 2
//   }

Here's the highlights:

• BSON-EXT support is back! Make sure you use bson-ext v4 with the driver v4.
• Our typescript got some big upgrades, you should get hinting and completion for filters in .find() and update specifiers in findOneAndUpdate()
• If you store regular expressions in mongodb from another language where the symbols are not supported in native JS regexes, you can now set the bsonRegExp flag to retrieve them

   await collection.insertOne({ a: new BSONRegExp('(?-i)AA_') })
   await collection.findOne({ a: new BSONRegExp('(?-i)AA_') }, { bsonRegExp: true })
   // { _id: ObjectId,  a: BSONRegExp { pattern: '(?-i)AA_', options: '' } }

⚠ BREAKING CHANGES

• NODE-3291: Standardize error representation in the driver (#2824)
• NODE-3272: emit correct event type when SRV Polling (#2825)
• NODE-2752: remove strict/callback mode from Db.collection helper (#2817)

Features

• NODE-2751: add arrayFilters builder to bulk FindOperators (#2820) (d099622)
• NODE-3274: add type hinting for UpdateFilter (#2842) (05035eb)
• NODE-3325: support 'let' option for aggregate command (#2828) (e38838e)
• NODE-3331: offer downleveled types for legacy typescript versions (#2859) (27cf1d2)
• NODE-3333: support 'let' option for CRUD commands (#2829) (0d91da1)

Bug Fixes

• NODE-1502: command monitoring objects hold internal state references (#2832) (a2887db)
• NODE-2026: SERVICE_REALM kerberos mechanism property not attached (#2865) (5caa354)
• NODE-2035: exceptions thrown from awaited cursor forEach do not propagate (#2835) (ac49df6)
• NODE-2905: support SERVICE_NAME authentication mechanism property (#2857) (dfb91b8)
• NODE-2944: Reintroduce bson-ext support (#2823) (8eb0081)
• NODE-3150: allow retrieving PCRE-style RegExp (ca9e2dc)
• NODE-3272: emit correct event type when SRV Polling (#2825) (579119f)
• NODE-3305: beforeHandshake flag is always true (#2854) (079bd6c)
• NODE-3311: InsertOneOptions extends CommandOperationOptions (#2816) (734b481)
• NODE-3335: do not validate explain verbosity in client (#2834) (1a57ba8)
• NODE-3343: allow overriding result document after projection applied (#2856) (988f9c8)
• NODE-3356: update redaction logic for command monitoring events (#2849) (536e5ff)
• NODE-3291: Standardize error representation in the driver (#2824) (9608c6a)
• NODE-2752: remove strict/callback mode from Db.collection helper (#2817) (53abfe7)

Documentation

• Reference: https://docs.mongodb.com/drivers/node
• API: https://mongodb.github.io/node-mongodb-native/4.0
• Changelog: https://github.com/mongodb/node-mongodb-native/blob/4.0/HISTORY.md

We invite you to try the mongodb library immediately, and report any issues to the NODE project.

The MongoDB Node.js team is pleased to announce version 4.0.0-beta.5 of the driver!

Release Highlights

This release further improves our TypeScript support with consistent enum naming and a better list of exported types.

Bug Fixes

• NODE-3183, NODE-3249: bring versioned API impl up to date (#2814) (cd3b73a)
• NODE-3245: mark symbols as internal remove from type definitions (#2810) (0b636ba)
• NODE-3275: Fix enum type export naming and serverApi validation (#2809) (661511d)

Documentation

• Reference: https://docs.mongodb.com/drivers/node
• API: https://mongodb.github.io/node-mongodb-native/4.0
• Changelog: https://github.com/mongodb/node-mongodb-native/blob/4.0/HISTORY.md

We invite you to try the mongodb package immediately, and report any issues to the NODE project.

The MongoDB Node.js team is pleased to announce version 4.0.0.beta.4 of the driver.

Release Highlights

This beta release brings optional support for Typescript generics when defining your collections

// Example:
interface Pet {
    type: 'cat' | 'dog' | 'fish'
}
const collection = db.collection<Pet>()
await collection.findOne({}).toArray() // returns Pet[]

as well as strong typing for events emitted by the MongoClient. For example, when listening to .on('commandStarted' event => ...), event here will be a CommandStartedEvent object.

We have a few breaking changes listed below, notably the node driver now aligns with other drivers by using the returnDocument option when determining whether to return the document before or after the update in findOneAndUpdate and findOneAndReplace.

⚠ BREAKING CHANGES

• NODE-1812: replace returnOriginal with returnDocument option (#2803)
• NODE-3157: update find and modify interfaces for 4.0 (#2799)
• NODE-2978: remove deprecated bulk ops (#2794)

Features

• NODE-3115: Add generic parameterization (#2767) (4d12491)
• NODE-3132: Add TypedEventEmitter (#2785) (f4d40a4)

Bug Fixes

• NODE-2995: Add shared metadata MongoClient (#2772) (9073d54)

• NODE-3074: update estimated document count for v1 api (#2764) (146791c)

• NODE-3109: prevent servername from being an IP (#2771) (27089be)

• NODE-3166: allowInvalidHostnames and allowInvalidCertificates flags are ignored (#2784) (a769cf8)

• NODE-3174: Preserve sort key order for numeric string keys (#2788) (440de41)

• NODE-3176: handle errors from MessageStream (#2780) (76b110e)

• NODE-3194: Ignore undefined and null options in MongoClient constructor (#2800) (8bb92f9)

• NODE-3197: revert setImmediate in waitQueue (#2802) (6c0dfef)

• NODE-3206: Make distinct use any[] type instead of Document[] (#2795) (b45e3b3)

• NODE-3219: topology no longer causes close event (#2792) (6cd982f)

• NODE-1812: replace returnOriginal with returnDocument option (#2803) (1cdc8a8)

• NODE-2978: remove deprecated bulk ops (#2794) (c3a1839)

• NODE-3157: update find and modify interfaces for 4.0 (#2799) (29512da)

---

Documentation

• Reference: https://docs.mongodb.com/drivers/node
• API: https://mongodb.github.io/node-mongodb-native/4.0
• Changelog: https://github.com/mongodb/node-mongodb-native/blob/4.0/HISTORY.md

We invite you to try the driver immediately, and report any issues to the NODE project.

To try the beta use the following command:

npm install mongodb@4.0.0-beta.4

Thanks very much to all the community members who contributed to this release!

The MongoDB Node.js team is pleased to announce version 4.0.0-beta.3 of the driver

This release brings us closer to the RC release for the fully typescript enabled version 4.0.0 of the driver. You can expect a full migration and detailed list of changes with the upcoming RC.

All Changes

• always close gridfs upload stream on finish (#2759) (1c6f544)
• don't auto destroy read stream for Node 14 (d4e297e)
• move session support check to operation layer (#2750) (c19f296)
• remove existing session from cloned cursors (30ccd86)
• NODE-3071: Ignore error message if error code is defined (#2770) (d4cc936)
• NODE-3152: ensure AWS environment variables are applied properly (#2756) (341a602)
• add fermium to evergreen test runs (#2762) (2303b41)

Documentation

• Reference: https://docs.mongodb.com/drivers/node
• API: https://mongodb.github.io/node-mongodb-native/4.0
• Changelog: https://github.com/mongodb/node-mongodb-native/blob/4.0/HISTORY.md

The MongoDB Node.js team is pleased to announce version 4.0.0-beta.2 of the driver

This release brings us closer to the RC release for the fully typescript enabled version 4.0.0 of the driver. You can expect a full migration and detailed list of changes with the upcoming RC.

Breaking Changes

• remove deprecated items (#2740)
  • All removals are noted here
• remove enums in favor of const objects (#2741)

All Changes

• add FLE AWS sessionToken TypeScript definitions (#2737) (f4698b5)
• remove catch for synchronous socket errors and remove validation on nodejs option (#2746) (a516903)
• session support detection spec compliance (#2733) (1615be0)
• remove deprecated items (#2740) (ee1a4d3)
• remove enums in favor of const objects (#2741) (d52c00e)

Documentation

Reference: https://docs.mongodb.com/drivers/node API: https://mongodb.github.io/node-mongodb-native/4.0 Changelog: https://github.com/mongodb/node-mongodb-native/blob/4.0/HISTORY.md

Release Highlights

This beta release addresses a few bugs relating to using CSFLE with the beta version of the driver. As well as a fix for BulkWriteResult and BulkWriteError to correctly reflect the operation's result information.

You can take a look at the raw updates list in our HISTORY.md file, we are intending to do a complete rundown of features and fixes with the v4.0.0 release.

You can give it a try with:

npm install mongodb@beta

If you have any suggestions about clarifying documentation or if you run into any issues or have any feature ideas please let us know! You can make an account and submit tickets to our JIRA project here.

Documentation

Reference: https://docs.mongodb.com/drivers/node API: https://mongodb.github.io/node-mongodb-native/4.0 Changelog: https://github.com/mongodb/node-mongodb-native/blob/4.0/HISTORY.md

The MongoDB Node.js team is pleased to announce a beta version v4.0.0-beta.0 of the driver.

A major motivation for releasing this beta was the migration of the entire code base to TypeScript. While we took special care to ensure a smooth transition, we imagine such a dramatic change might reveal unexpected issues. This beta release makes it easy to easily check compatibility with your application and make use of the included type definitions.

Additionally, we are publishing an early version of the new API documentation https://mongodb.github.io/node-mongodb-native/4.0.

You can take a look at the raw updates list in our HISTORY.md file, we are intending to do a complete rundown of features and fixes with the v4.0.0 release.

You can give it a try with:

npm install mongodb@beta

If you have any suggestions about clarifying documentation or if you run into any issues or have any feature ideas please let us know! You can make an account and submit tickets to our JIRA project here.

Documentation

Reference: https://docs.mongodb.com/drivers/node API: https://mongodb.github.io/node-mongodb-native/4.0 Changelog: https://github.com/mongodb/node-mongodb-native/blob/4.0/HISTORY.md

The MongoDB Node.js team is pleased to announce version 3.7.4 of the mongodb package!

Release Highlights

This release fixes a bug that throws a type error when SCRAM-SHA-256 is used with saslprep in a webpacked environment.

3.7.4 (2023-06-21)

Bug Fixes

• NODE-3711: retry txn end on retryable write (#3047) (1595140)
• NODE-5355: prevent error when saslprep is not a function (#3733) (152425a)

Documentation

• Reference
• API
• Changelog

We invite you to try the mongodb library immediately, and report any issues to the NODE project.

The MongoDB Node.js team is pleased to announce version 3.7.3 of the mongodb package!

What's Changed

• fix(NODE-3515): do proper opTime merging in bulk results by @durran in https://github.com/mongodb/node-mongodb-native/pull/3011

Full Changelog: https://github.com/mongodb/node-mongodb-native/compare/v3.7.2...v3.7.3

Documentation

• Reference: https://docs.mongodb.com/drivers/node
• API: https://mongodb.github.io/node-mongodb-native/3.7
• Changelog: https://github.com/mongodb/node-mongodb-native/blob/3.7/HISTORY.md

We invite you to try the mongodb library immediately, and report any issues to the NODE project.

The MongoDB Node.js team is pleased to announce version 3.7.2 of the mongodb package!

Release Highlights

This release contains a fix for optional require of dependencies on yarn berry.

Bug Fixes

• NODE-3622: bump optional-require for additional yarn berry pnp support (#2989) (ec23d6302)

Documentation

• Reference: https://docs.mongodb.com/drivers/node
• API: https://mongodb.github.io/node-mongodb-native/3.7
• Changelog: https://github.com/mongodb/node-mongodb-native/blob/3.7/HISTORY.md

We invite you to try the mongodb library immediately, and report any issues to the NODE project.

The MongoDB Node.js team is pleased to announce version 3.7.1 of the mongodb package!

Release Highlights

This release contains an internal improvement that makes our monitor utilize the new hello handshake for monitoring when available.

Features

• NODE-3424: use hello for monitoring commands (#2964) (910c564)

Documentation

• Reference: https://docs.mongodb.com/drivers/node
• API: https://mongodb.github.io/node-mongodb-native/3.7
• Changelog: https://github.com/mongodb/node-mongodb-native/blob/3.7/HISTORY.md

We invite you to try the mongodb library immediately, and report any issues to the NODE project.

The MongoDB Node.js team is pleased to announce version 3.7.0 of the mongodb package!

Release Highlights

Versioned API

Versioned API is a new feature in MongoDB 5.0 that allows user-selectable API versions, subsets of MongoDB server semantics, to be declared on a client. During communication with a server, clients with a declared API version will force the server to behave in a manner compatible with the API version. Declaring an API version on a client can be used to ensure consistent responses from a server, providing long term API stability for an application. The declared API version is applied to all commands run through the client, including those sent through the generic RunCommand helper. Specifying versioned API options in the command document AND declaring an API version on the client is not supported and will lead to undefined behavior.

Declare an API version on a client

// Declare API version "1" for the client
client = new MongoClient(uri, { serverApi: { version: '1' } });

cursor = client.db('database').collection('coll').find(...);

Strict mode

Declaring a strict API version will cause the MongoDB server to reject all commands that are not part of the declared API version. This includes command options and aggregation pipeline stages. For example, the following find call would fail because the tailable option is not part of version 1:

// Declare API version "1" for the client, with strict on
client = new MongoClient(uri, { serverApi: { version: '1', strict: true } });

// Fails with an error
cursor = client.db('database').collection('coll').find({ ... }, { tailable: true });

Deprecation Errors

The deprecationErrors option can be used to enable command failures when using functionality that is deprecated from version 1. Note that at the time of this writing, no deprecations in version 1 exist.

// Declare API version "1" for the client, with deprecationErrors on
client = new MongoClient(uri, { serverApi: { version: '1', deprecationErrors: true } });

// Note: since API version "1" is the initial version, there are no deprecated commands to provide as an example yet.

Features

• NODE-3191: backport versioned api (#2850) (93a47fd)

Bug Fixes

• NODE-3377: driver should allow arbitrary explain levels (#2961) (96c8ab4)
• NODE-3463: pass explain error through to callback (#2949) (e5975af)

Documentation

• Reference: https://docs.mongodb.com/drivers/node/current/
• API: https://mongodb.github.io/node-mongodb-native/3.7/api/
• Changelog: https://github.com/mongodb/node-mongodb-native/blob/v3.7.0/HISTORY.md

We invite you to try the mongodb library immediately, and report any issues to the NODE project.

The MongoDB Node.js team is pleased to announce version 3.6.12 of the mongodb package!

Bug Fixes

• NODE-3487: check for nullish aws mechanism property (#2957) (5902b4c)
• NODE-3528: add support for snappy v7 (#2947) (54f5c2d)

Documentation

• Reference: https://docs.mongodb.com/drivers/node/current/
• API: https://mongodb.github.io/node-mongodb-native/3.6/api/
• Changelog: https://github.com/mongodb/node-mongodb-native/blob/v3.6.12/HISTORY.md

We invite you to try the mongodb library immediately, and report any issues to the NODE project.

The MongoDB Node.js team is pleased to announce version 3.6.11 of the mongodb package!

Release Highlights

This patch addresses a few bugs listed below. Notably, we fixed an issue with the way we imported one of our optional dependencies that blocked webpack bundling.

If you are a webpack user you will still get warnings for our optional dependencies (if you don't use them). You can hush the warnings by adding this option to your webpack config:

{
    // ...
    externals: [
        'mongodb-client-encryption',
        'aws4',
        'saslprep',
        'kerberos',
        'snappy',
        'bson-ext',
    ],
    // ...
}

It is important to note that this will leave the imports in place and not pull in the code to your bundle. If you later do adopt using these dependencies you'll want to revert the relevant setting.

Bug Fixes

• NODE-1843: bulk operations ignoring provided sessions (#2898) (9244b17)
• NODE-3199: unable to bundle driver due to uncaught require (#2903) (60efe9d)

Documentation

• Reference: https://docs.mongodb.com/drivers/node/current/
• API: http://mongodb.github.io/node-mongodb-native/3.6/api
• Changelog: https://github.com/mongodb/node-mongodb-native/blob/3.6/HISTORY.md

We invite you to try the mongodb package immediately, and report any issues to the NODE project.

The MongoDB Node.js team is pleased to announce version 3.6.10 of the mongodb package!

Release Highlights

This patch addresses a few bugs listed below. Notably the bsonRegExp option is now respected by the underlying BSON library, you can use this to decode regular expressions that contain syntax not permitted in native JS RegExp objects. Take a look at this example:

await collection.insertOne({ a: new BSONRegExp('(?-i)AA_') })
await collection.findOne({ a: new BSONRegExp('(?-i)AA_') }, { bsonRegExp: true })
// { _id: ObjectId,  a: BSONRegExp { pattern: '(?-i)AA_', options: '' } }

Also there was an issue with Cursor.forEach where user defined forEach callbacks that throw errors incorrectly handled catching errors. Take a look at the comments in this example:

collection.find({}).forEach(doc => {
    if(doc.bad) throw new Error('bad document!');
}).catch(error => {
    // now this is called! and error is `bad document!`
})
// before this fix the `bad document!` error would be thrown synchronously
// and have to be caught with try catch out here

Bug Fixes

• NODE-2035: Exceptions thrown from awaited cursor forEach do not propagate (#2852) (a917dfa)
• NODE-3150: added bsonRegExp option for v3.6 (#2843) (e4a9a57)
• NODE-3358: Command monitoring objects hold internal state references (#2858) (750760c)
• NODE-3380: perform retryable write checks against server (#2861) (621677a)
• NODE-3397: report more helpful error with unsupported authMechanism in initial handshake (#2876) (3ce148d)

Documentation

• Reference: https://docs.mongodb.com/drivers/node/current/
• API: http://mongodb.github.io/node-mongodb-native/3.6/api
• Changelog: https://github.com/mongodb/node-mongodb-native/blob/3.6/HISTORY.md

We invite you to try the mongodb package immediately, and report any issues to the NODE project.

The MongoDB Node.js team is pleased to announce version 3.6.9 of the driver!

Release Highlights

This release fixes a major performance bug in bulk write operations, which was inadvertently introduced by an incomplete code change in the previous release. The bug resulted in redundant array iterations and caused exponential increases in bulk operation completion times. Thank you Jan Schwalbe for bringing this to our attention!

Bug Fixes

• NODE-3309: remove redundant iteration of bulk write result (#2815) (fac9610)
• NODE-3234: fix url parsing for a mongodb+srv url that has commas in the database name (#2789) (58c4e69)

Documentation

• Reference: https://docs.mongodb.com/drivers/node/current/
• API: http://mongodb.github.io/node-mongodb-native/3.6/api
• Changelog: https://github.com/mongodb/node-mongodb-native/blob/3.6/HISTORY.md

We invite you to try the mongodb package immediately, and report any issues to the NODE project.

The MongoDB Node.js team is pleased to announce version 3.6.8 of the mongodb package!

Release Highlights

Thanks to the quick adoption of the previous new patch by the mongoose package (https://github.com/Automattic/mongoose/pull/10265) a small bug was identified when connections to mongodb would timeout causing unnecessary clean up operations to run. Thank you @vkarpov15!

Bug Fixes

• NODE-3305: undo flipping of beforeHandshake flag for timeout errors (#2813) (6e3bab3)

Documentation

• Reference: https://docs.mongodb.com/drivers/node/current/
• API: http://mongodb.github.io/node-mongodb-native/3.6/api
• Changelog: https://github.com/mongodb/node-mongodb-native/blob/3.6/HISTORY.md

We invite you to try the mongodb package immediately, and report any issues to the NODE project.

The MongoDB Node.js team is pleased to announce version 3.6.7 of the driver

Release Highlights

This patch addresses a number of bug fixes. Notably, there was an interesting javascript related issue with sorting documents. It only impacts users using numerical keys in their documents.

> { a: 'asc', [23]: 'asc' }
{ [23]: 'asc', a: 'asc' } // numbers come first

In javascript, numerical keys are always iterated first when looping over the keys of an object followed by the chronological specification of each string key. This effectively changes the ordering of a sort document sent to mongodb. However our driver does accept sort specification in a variety of ways and one way to avoid this problem is passing an array of tuples:

[['a', 'asc'], ['23', 'asc']]

This ensures that mongodb is sent the 'a' key as the first sort key and '23' as the second.

Bug Fixes

• NODE-3159: removing incorrect apm docs (#2793) (971259a)
• NODE-3173: Preserve sort key order for numeric string keys (#2790) (730f43a)
• NODE-3176: handle errors from MessageStream (#2774) (f1afcc4)
• NODE-3192: check clusterTime is defined before access (#2806) (6ceace6)
• NODE-3252: state transistion from DISCONNECTED (#2807) (5d8f649)
• NODE-3219: topology no longer causes close event (#2791) (16e7064)
• invalid case on writeconcern makes skip check fail (#2773) (b1363c2)

Documentation

• Reference: http://mongodb.github.io/node-mongodb-native/3.6
• API: http://mongodb.github.io/node-mongodb-native/3.6/api
• Changelog: https://github.com/mongodb/node-mongodb-native/blob/3.6/HISTORY.md

We invite you to try the driver immediately, and report any issues to the NODE project.

Thanks very much to all the community members who contributed to this release!

The MongoDB Node.js team is pleased to announce version 3.6.6 of the driver

Release Highlights

This patch addresses a number of bugs listed below. Most notably, for client side encryption users upgrading to this version of the driver along with the new version of mongodb-client-encryption@1.2.3 will alleviate the potential deadlock case if your connection pool was fully utilized. There will now be an internal MongoClient that will be used for metadata look ups (e.g, listCollections) when the pool size is under certain constraints. The events generated from this client are forwarded to the client instance you initialize so it is possible to monitor all events.

Bug

• [NODE-2995] - Sharing a MongoClient for metadata lookup can lead to deadlock in drivers using automatic encryption
• [NODE-3050] - Infinite loop on Windows due to a bug in require_optional package
• [NODE-3120] - TypeError: Cannot read property 'roundTripTime' of undefined
• [NODE-3122] - Pipelining an upload stream of GridFSBucket never finishes on Node v14
• [NODE-3129] - Collection () .. .setReadPreference() not routing query to secondaries
• [NODE-3133] - autoEncryption produces serverHeartbeatFailed - with MongoError typemismatch

Improvement

• [NODE-3070] - Define error handling behavior of writeErrors and writeConcernError on Mongos

Documentation

• Reference: http://mongodb.github.io/node-mongodb-native/3.6
• API: http://mongodb.github.io/node-mongodb-native/3.6/api
• Changelog: https://github.com/mongodb/node-mongodb-native/blob/3.6/HISTORY.md

We invite you to try the driver immediately, and report any issues to the NODE project.

Thanks very much to all the community members who contributed to this release!

The MongoDB Node.js team is pleased to announce version 3.6.5 of the driver!

Notable Fixes

In this patch there is a fix surrounding an issue some users were encountering in serverless environments when using the Unified Topology. If the nodejs process went unused for a great amount of time there was an intermittent issue that would cause startSession to fail, however, issuing a dummy read request would resolve the problem. The session support check is now done after server selection meaning the driver has the most up to date information about the MongoDB deployment before utilizing sessions. We encourage any user's that implemented workarounds to updated their driver and make use of this fix.

In addition, the previous release of our driver added a warning about an upcoming change in the v4 version of the driver about how users can specify their write concern options. We've updated the driver to use nodejs's process.emitWarning API in nearly all cases where the driver prints something out, as well as limit most warning messages to only be printed once.

Bug

• session support detection spec compliance (#2732) (9baec71)
• [NODE-3100] - startSession fails intermittently on servers that support sessions
• [NODE-3066] - Accessing non-existent property 'MongoError' of module exports inside circular dependency
• [NODE-3114] - Incorrect warning: Top-level use of w, wtimeout, j, and fsync is deprecated
• [NODE-3119] - Node 14.5.4, mongo 3.6.4 Circular warnings

MongoDB Driver v3.6.4

The MongoDB Node.js team is pleased to announce version 3.6.4 of the driver

Release Highlights

Explain Support

The full set of $explain verbosity settings are now supported:

• queryPlanner
• queryPlannerExtended
• executionStats
• allPlansExecution

In the following commands:

• aggregate() (MDB 3.0+)
• find() (MDB 3.0+)
• remove() (MDB 3.0+)
• update() (MDB 3.0+)
• distinct() (MDB 3.2+)
• findAndModify() (MDB 3.2+)
• mapReduce() (MDB 4.4+)

You can get a lot of insight into the performance of a query or optimization using these fine grained reports. To learn more about how to use explain read here.

Direct Connection Issue Revert

We removed automatic direct connection for the unified topology in the 3.6.3 release of the driver. This change was preparatory for the 4.0 version of the driver, where we'll always perform automatic discovery. To avoid making this kind of change in a patch release, this version restores automatic direct connection when connecting to a single host using the unified topology without a specified replicaSet and without directConnection: false, in line with previous 3.6 releases.

NOTE: In the next major version the unifiedTopology is the only Topology and it is required to either specify a replicaSet name or enable directConnection in order to connect to single nodes in a replica set.

Support Azure and GCP keystores in FLE

There are no functional changes to the driver to support using Azure and GCP keystores but a new mongodb-client-encryption release (v1.2.0) can be found here which prominently features support for these key stores.

Documentation

• Reference: http://mongodb.github.io/node-mongodb-native/3.6
• API: http://mongodb.github.io/node-mongodb-native/3.6/api
• Changelog: https://github.com/mongodb/node-mongodb-native/blob/3.6/HISTORY.md

We invite you to try the driver immediately, and report any issues to the NODE project.

Thanks very much to all the community members who contributed to this release!

Release Notes

Bug

• [NODE-2355] - GridFSBucketWriteStream doesn't implement stream.Writable properly
• [NODE-2828] - noCursorTimeout does not seem to for find()
• [NODE-2874] - Setting connectionTimeoutMS to 0 will result in a disconnection every heartbeatFrequencyMS
• [NODE-2876] - Race condition when resetting server monitor
• [NODE-2916] - Legacy topology hangs with unlimited socket timeout
• [NODE-2945] - ignoreUndefined not works on findOneAndUpdate when { upsert: true }
• [NODE-2965] - MongoClient.readPreference returns "primary" ignoring readPref from connection string
• [NODE-2966] - Unified topology: server selection fails when trying to connect to a remote replica set with a member whose 'host' attribute resolves to 'localhost'
• [NODE-2977] - Query parameters with path in connection string not working on windows
• [NODE-2986] - MongoError: pool destroyed

Features

• [NODE-2762] - Comprehensive Support for Explain
• [NODE-2852] - Add explain support to non-cursor commands
• [NODE-2853] - Add explain support to cursor-based commands

Improvement

• [NODE-1726] - Deprecate Topology events in Db
• [NODE-2825] - Support Azure and GCP keystores in FLE
• [NODE-2880] - Improve stack traces in the session leak checker
• [NODE-2895] - Update AggregateCursor "unwind" method to match the native driver
• [NODE-2995] - Sharing a MongoClient for metadata lookup can lead to deadlock in drivers using automatic encryption

The MongoDB Node.js team is pleased to announce version 3.6.3 of the driver

Release Highlights

MongoError: not master when running createIndex

A regression introduced in v3.6.2 meant that createIndex operations would not be executed with a fixed primary read preference. This resulted in the driver selecting any server for the operation, which would fail if a non-primary was selected.

Performance issues on AWS Lambda

The driver periodically monitors members of the replicaset for changes in the topology, but ensures that the "monitoring thread" is never woken sooner than 500ms. Measuring this elapsed time depends on a stable clock, which is not available to us in some virtualized environments like AWS Lambda. The result was that periodically operations would think there were no available servers, and the driver would force a wait of heartbeatFrequencyMS (10s by default) before reaching out to servers again for a new monitoring check. The internal async interval timer has been improved to account for these environments

GSSAPI AuthProvider reuses single kerberos client

A regression introduced in v3.6.0 forced the driver to reuse a single kerberos client for all authentication attempts. This would result in incomplete authentication flows, and occaisionally even a crash in the kerberos module. The driver has been reverted to creating a kerberos client per authentication attempt.

Performance regression due to use of setImmediate

A change introduced in v3.6.1 switched all our usage of process.nextTick in the connection pool with setImmediate per Node.js core recommendation. This was observed to introduce noticeable latency when the event loop was experiencing pressure, so the change was reverted for this release pending further investigation.

Community Contributions

• @jswangjunsheng submitted a fix for a rare scenario when wait queue members time out before connection establishment
• @through-a-haze submitted a fix for incorrect construction of an X509 authentication message
• @andreialecu helped us indicate peer optional dependencies in our package.json for stricter package managers (pnpm, yarn2)

Documentation

Reference: http://mongodb.github.io/node-mongodb-native/3.6/ API: http://mongodb.github.io/node-mongodb-native/3.6/api/ Changelog: https://github.com/mongodb/node-mongodb-native/blob/3.6/HISTORY.md

We invite you to try the driver immediately, and report any issues to the NODE project.

Thanks very much to all the community members who contributed to this release!

Release Notes

<h2> Bug </h2> <ul> <li>[<a href='https://jira.mongodb.org/browse/NODE-2172'>NODE-2172</a>] - Change stream breaks on disconnection when there's something piped into it. </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2784'>NODE-2784</a>] - MongoError: Not Master when running createIndex in 3.6.0 </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2807'>NODE-2807</a>] - MongoClient.readPreference always returns primary </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2827'>NODE-2827</a>] - Connecting to single mongos makes driver think it is connected to a standalone </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2829'>NODE-2829</a>] - MongoDB Driver 3.6+ Performance issues on AWS Lambda </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2835'>NODE-2835</a>] - Remove default timeout for read operations </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2859'>NODE-2859</a>] - GSSAPI AuthProvider causing crashes in Compass </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2861'>NODE-2861</a>] - Performance Regression for usage of mongodb connections (queries, inserts, ...) </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2865'>NODE-2865</a>] - Connections can be leaked if wait queue members are cancelled </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2869'>NODE-2869</a>] - Invalid assignment of X509 username makes authentication impossible </li> </ul>

<h2> Improvement </h2> <ul> <li>[<a href='https://jira.mongodb.org/browse/NODE-2834'>NODE-2834</a>] - Remove deprecation of AggregationCursor#geoNear </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2867'>NODE-2867</a>] - Use peerDependenciesMeta field to mark peer optional dependencies </li> </ul>

The MongoDB Node.js team is pleased to announce version 3.6.2 of the driver

Release Highlights

Updated bl dependency due to CVE-2020-8244

See this link for more details: https://github.com/advisories/GHSA-pp7h-53gx-mx7r

Connection pool wait queue processing is too greedy

The logic for processing the wait queue in our connection pool ran the risk of starving the event loop. Calls to process the wait queue are now wrapped in a setImmediate to prevent starvation

Documentation

Reference: http://mongodb.github.io/node-mongodb-native/3.6/ API: http://mongodb.github.io/node-mongodb-native/3.6/api/ Changelog: https://github.com/mongodb/node-mongodb-native/blob/3.6/HISTORY.md

We invite you to try the driver immediately, and report any issues to the NODE project.

Thanks very much to all the community members who contributed to this release!

Release Notes

<h3> Bug </h3> <ul> <li>[<a href='https://jira.mongodb.org/browse/NODE-2798'>NODE-2798</a>] - Update version of dependency "bl" due to vulnerability </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2803'>NODE-2803</a>] - Connection pool wait queue processing is too greedy </li> </ul>

The MongoDB Node.js team is pleased to announce version 3.6.1 of the driver

Release Highlights

Kerberos

A bug in introducing the new CMAP Connection prevented some users from properly authenticating with the kerberos module.

Index options are not respected with createIndex

The logic for building the createIndex command was changed in v3.6.0 to use an allowlist rather than a blocklist, but omitted a number of index types in that list. This release reintroduces all supported index types to the allowlist.

Remove strict mode for createCollection

Since v3.6.0 createCollection will no longer returned a cached Collection instance if a collection already exists in the database, rather it will return a server error stating that the collection already exists. This is the same behavior provided by the strict option for createCollection, so that option has been removed from documentation.

Documentation

Reference: http://mongodb.github.io/node-mongodb-native/3.6/ API: http://mongodb.github.io/node-mongodb-native/3.6/api/ Changelog: https://github.com/mongodb/node-mongodb-native/blob/3.6/HISTORY.md

We invite you to try the driver immediately, and report any issues to the NODE project.

Thanks very much to all the community members who contributed to this release!

Release Notes

<h3> Bug </h3> <ul> <li>[<a href='https://jira.mongodb.org/browse/NODE-2731'>NODE-2731</a>] - CMAP Connection type does not provide host/port properties </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2755'>NODE-2755</a>] - "language_override" option support for text index is broken </li> </ul>

<h2> Improvement </h2> <ul> <li>[<a href='https://jira.mongodb.org/browse/NODE-2730'>NODE-2730</a>] - Move MongoAuthProcess into the driver source tree </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2746'>NODE-2746</a>] - Strict mode for createCollection should be removed </li> </ul>

The MongoDB Node.js team is pleased to announce version 3.6.0 of the driver

NOTE: This version begins our official support for MongoDB 4.4

Release Highlights

Streaming topology changes

MongoDB drivers maintain a local view of the topology they are connected to, and ensure the accuracy of that view by polling connected nodes on average every ~10s. In MongoDB 4.4, drivers are now able to receive push notifications about topology updates, effectively reducing the time for client recovery in failover scenarios to the time it takes for the server to make the election and report the outcome.

This feature is enabled by default when connecting to MongoDB 4.4, no changes are needed for user code.

Authentication

MONGODB-AWS authentication mechanism

The MONGODB-AWS authentication mechanism uses your Amazon Web Services Identity and Access Management (AWS IAM) credentials to authenticate users on MongoDB 4.4+. Please read more about this new authentication mechanism in our documentation.

Performance improvements

There were two projects to transparently improve performance of authentication in MongoDB 4.4:

• A driver can now include the first saslStart command in its initial handshake with server. This so-called "speculative authentication" allows us to reduce one roundtrip to the server for authentication a connection. This feature is only support for X.509, SCRAM-SHA-1 and SCRAM-SHA-256 (default) authentication mechanisms.

• The SCRAM conversation between driver and server can now skip one of it's empty exchanges which also serves to reduce the roundtrips during a SCRAM authentication.

Changes in behavior of Db.prototype.createCollection

The createCollection helper used to internally run a listCollections command in order to see if a collection already existed before running the command. If it determined a collection with the same name existed, it would skip running the command and return an instance of Collection. This behavior was changed in v3.6.0 to avoid potentially serious bugs, specifically that the driver was not considering options passed into createCollection as part of the collection equality check. Imagine the following scenario:

const client = new MongoClient('...');
await client.connect();
 
await client.db('foo').collection('bar').insert({ importantField: 'llamas' });
await client.db('foo').createCollection('bar', {
  validator: { $jsonSchema: {
    bsonType: 'object',
    required: ['importantField'],
    properties: { name: { bsonType: 'boolean' } }
  }
});

The createCollection call which defines a JSON schema validator would be completely bypassed because of the existence of bar, which was implicitly created in the first command. Our policy is strictly adhere to semver, but in rare cases like this where we feel there is potential for a data corrupting bug, we make breaking behavioral changes to protect the user.

Documentation

Reference: http://mongodb.github.io/node-mongodb-native/3.6/ API: http://mongodb.github.io/node-mongodb-native/3.6/api/ Changelog: https://github.com/mongodb/node-mongodb-native/blob/3.6/HISTORY.md

We invite you to try the driver immediately, and report any issues to the NODE project.

Thanks very much to all the community members who contributed to this release!

Release Notes

<h3> Epic </h3> <ul> <li>[<a href='https://jira.mongodb.org/browse/NODE-2450'>NODE-2450</a>] - Node MongoDB 4.4 Support </li> </ul>

<h3> New Feature </h3> <ul> <li>[<a href='https://jira.mongodb.org/browse/NODE-2434'>NODE-2434</a>] - Reduce Client Time To Recovery On Topology Changes </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2288'>NODE-2288</a>] - MONGODB-AWS Support </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2289'>NODE-2289</a>] - Support for allowDiskUse on find operations </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2290'>NODE-2290</a>] - Allow passing hint to findAndModify update and replace operations </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2291'>NODE-2291</a>] - Improve testing around default writeConcern </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2295'>NODE-2295</a>] - Collection and index creation in multi-doc txns </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2427'>NODE-2427</a>] - OCSP Support </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2487'>NODE-2487</a>] - Support speculative authentication attempts in isMaster </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2301'>NODE-2301</a>] - Support shorter SCRAM conversation </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2269'>NODE-2269</a>] - Add support for validate command "background" option </li> </ul>

<h3> Improvement </h3> <ul> <li>[<a href='https://jira.mongodb.org/browse/NODE-2175'>NODE-2175</a>] - Avoid using readConcern snapshot in sharded transaction tests </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2176'>NODE-2176</a>] - Resync bson-corpus array.json to fix duplicate test names </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2393'>NODE-2393</a>] - Change uri_options/auth-options spec test to enable conditional tests </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2394'>NODE-2394</a>] - Verify max set version and max election id on topologies in SDAM spec tests </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2422'>NODE-2422</a>] - Validate that mongocryptd is not spawned if bypassAutoEncryption=true </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2430'>NODE-2430</a>] - Raise error if hint specified for unacknowledged update using OP_MSG or OP_UPDATE </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2431'>NODE-2431</a>] - Reduce floating point precision required of extended json implementations </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2432'>NODE-2432</a>] - Clarify behavior when "me" field doesn't match any values in "hosts" array </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2477'>NODE-2477</a>] - Allow hinting the delete command </li>

<li>[<a href='https://jira.mongodb.org/browse/NODE-2504'>NODE-2504</a>] - Add SDAM test for incompatible server becoming compatible </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2506'>NODE-2506</a>] - Ensure that the WriteConcernError "errInfo" object is propagated </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2538'>NODE-2538</a>] - Add RetryableWriteError error labels to retryable transaction tests </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2546'>NODE-2546</a>] - Deprecate geoHaystack and geoSearch </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2559'>NODE-2559</a>] - Reduce race conditions in SDAM error handling </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2560'>NODE-2560</a>] - Make 'reIndex' a standalone-only command </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2564'>NODE-2564</a>] - Clarify how a driver must handle wrong set name in single topology </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2569'>NODE-2569</a>] - 'CommitQuorum' option support for 'createIndexes’ command on MongoDB 4.4 </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2576'>NODE-2576</a>] - Raise error when hint option is provided on unacknowledged writes against any server version </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2592'>NODE-2592</a>] - Update documentation for Text Search </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2594'>NODE-2594</a>] - Do not add the RetryableWriteError label to errors that occur during a write within a transaction (excepting commitTransaction and abortTransaction) </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2622'>NODE-2622</a>] - allowDiskUse option for find should be documented as only being supported in 4.4+ </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2627'>NODE-2627</a>] - Reduce default keepalive time to align with Azure defaults </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2659'>NODE-2659</a>] - Drivers should retry replSetStepDown after "Unable to acquire X lock" error </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2661'>NODE-2661</a>] - Define behavior of connectTimeoutMS=0 with streaming protocol </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2675'>NODE-2675</a>] - Test that ElectionInProgress is not resumed </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2682'>NODE-2682</a>] - Treat CursorNotFound as a resumable change stream error </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2150'>NODE-2150</a>] - Bump wire protocol version for 4.4 </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2379'>NODE-2379</a>] - Expand use of error labels for RetryableWrites </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2423'>NODE-2423</a>] - Deprecate oplogReplay find command option from CRUD spec </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2426'>NODE-2426</a>] - Make ExceededTimeLimit retryable writes error </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2429'>NODE-2429</a>] - GridFS index checking should support indexes created in the shell </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2433'>NODE-2433</a>] - Lift restriction on authSource without credentials </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2452'>NODE-2452</a>] - Unify behavior around configuration for replica set discovery </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2510'>NODE-2510</a>] - Driver support for server Hedged Reads </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2516'>NODE-2516</a>] - Update comment in Transactions withTxn examples for the manual. </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2557'>NODE-2557</a>] - Remove replicaset from tests that perform reIndex command </li> </ul>

<h3> Bug </h3> <ul> <li>[<a href='https://jira.mongodb.org/browse/NODE-2416'>NODE-2416</a>] - Confusing documentation for collection.aggregate collation option </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2502'>NODE-2502</a>] - replaceOne example in test/examples/update_documents.js incorrect </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2537'>NODE-2537</a>] - createCollection helper should not run listIndexes outside of strict mode </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2567'>NODE-2567</a>] - Fix qs dependency for older node </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2616'>NODE-2616</a>] - SDAM test typo "compatible" </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2623'>NODE-2623</a>] - Gridfs doesn't allow to catch exception with length that exceeds file size </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2660'>NODE-2660</a>] - Throw an error if bulk update documents don't contain update operator expressions </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2711'>NODE-2711</a>] - Monitoring should not be immediately scheduled on streaming failure </li> </ul>

The MongoDB Node.js team is pleased to announce version 3.5.11 of the driver

Release Highlights

Kerberos

A bug in introducing the new CMAP Connection prevented some users from properly authenticating with the kerberos module.

Updated bl dependency due to CVE-2020-8244

See this link for more details: https://github.com/advisories/GHSA-pp7h-53gx-mx7r

Documentation

Reference: http://mongodb.github.io/node-mongodb-native/3.5/ API: http://mongodb.github.io/node-mongodb-native/3.5/api/ Changelog: https://github.com/mongodb/node-mongodb-native/blob/3.5/HISTORY.md

We invite you to try the driver immediately, and report any issues to the NODE project.

Thanks very much to all the community members who contributed to this release!

Release Notes

<h3> Bug </h3> <ul> <li>[<a href='https://jira.mongodb.org/browse/NODE-2731'>NODE-2731</a>] - CMAP Connection type does not provide host/port properties </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2798'>NODE-2798</a>] - Update version of dependency "bl" due to vulnerability </li> </ul>

The MongoDB Node.js team is pleased to announce version 3.5.10 of the driver

NOTE: This will be the final release in the 3.5.x branch, please consider upgrading to 3.6.0

Release Highlights

TypeError: Cannot read property 'documents' of null

@adrian-gierakowski helped us identify a bug with our ChangeStreamCursor, specifically when the cursor was complete it would not return a valid document but instead a null value.

Command helper not respecting server selection specification rules

The server selection specification indicates that the "runCommand" helper should act as a read operation for the purposes of server selection, and that it should use a default read preference of "primary" which can only be overridden by the helper itself. The driver had a bug where it would inherit the read preference from its "parent" type (Collection, Db, MongoClient) which is at odds with the specified behavior.

mongodb+srv invalid IPv6 support

Due to a bug in how we referred to ipv6 addresses internal to the driver, if a mongodb+srv connection string was provided with an ipv6 address the driver would never be able to connect and would result in a the following error RangeError: Maximum call stack size exceeded.

maxStalenessSeconds not accepted when provided via options

There was a bug in our connection string and MongoClient options parsing where a value provided for maxStalenessSeconds would not end up being reflected in the ReadPreference used internal to the driver.

Sessions are prohibited with unacknowledged writes

MongoDB can provide no guarantees around unacknowledged writes when used within a session. The driver will now silently remove the lsid field from all writes issued with { w: 0 }, and will return an error in these situations in the upcoming 4.0 major release.

Documentation

Reference: http://mongodb.github.io/node-mongodb-native/3.5/ API: http://mongodb.github.io/node-mongodb-native/3.5/api/ Changelog: https://github.com/mongodb/node-mongodb-native/blob/3.5/HISTORY.md

We invite you to try the driver immediately, and report any issues to the NODE project.

Thanks very much to all the community members who contributed to this release!

Release Notes

<h3> Bug </h3> <ul> <li>[<a href='https://jira.mongodb.org/browse/NODE-2626'>NODE-2626</a>] - initialising change stream results in: TypeError: Cannot read property 'documents' of null </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2649'>NODE-2649</a>] - Driver 3.5.x with useUnifiedTopology sends admin commands to secondary </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2671'>NODE-2671</a>] - ipv6 is not supported when using dns service discovering </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2678'>NODE-2678</a>] - ReadPreference.fromOptions doesn't pull "maxStalenessSeconds" from options </li> </ul>

<h3> Improvement </h3> <ul> <li>[<a href='https://jira.mongodb.org/browse/NODE-1341'>NODE-1341</a>] - Prohibit using unacknowledged writes with explicit sessions </li> </ul>

The MongoDB Node.js team is pleased to announce version 3.5.9 of the driver

Release Highlights

Use duration of handshake if no previous roundTripTime exists

The default roundTripTime of a ServerDescription is -1, which means if that value is used we can potentially calculate a negative roundTripTime. Instead, if no previous roundTripTime exists, we use the duration of the initial handshake.

the options [maxIdleTimeMS] is not supported

A number of new options were added when the CMAP compliant connection pool was introduced in 3.5.x. Unfortunately, these options were not documented properly. Now they are mentioned in the MongoClient documentation, with a notice that they are only supported with the unified topology.

TypeError: Reduce of empty array with no initial value

A fix in 3.5.8 which ensured proper filtering of servers during server selection exposed an issue in max staleness calculations when the topology type is ReplicaSetNoPrimary and no servers are currently known. In order to estimate an upper bound of max staleness when there is no primary, the most stale known server is known to compare the others to - if there are no known servers, you can't reduce the array!

Server monitoring is prevented under heavy request load

In certain very high load fail-over scenarios the driver is unable to reschedule a monitoring check in order to update its view of the topology for retryability. This would result in a high number of failed operations, as they were unable to determine a new viable server.

Documentation

Reference: http://mongodb.github.io/node-mongodb-native/3.5/ API: http://mongodb.github.io/node-mongodb-native/3.5/api/ Changelog: https://github.com/mongodb/node-mongodb-native/blob/3.5/HISTORY.md

We invite you to try the driver immediately, and report any issues to the NODE project.

Thanks very much to all the community members who contributed to this release!

Release Notes

<h3> Bug </h3> <ul> <li>[<a href='https://jira.mongodb.org/browse/NODE-2637'>NODE-2637</a>] - connection pool options support for MongoClient </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2641'>NODE-2641</a>] - maxStalenessReducer fails on empty set of servers </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2643'>NODE-2643</a>] - Server monitoring is prevented under heavy request load </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2652'>NODE-2652</a>] - Use duration of initial handshake if no roundTripTime value exists for server </li> </ul>

<h3> Improvement </h3> <ul> <li>[<a href='https://jira.mongodb.org/browse/NODE-2651'>NODE-2651</a>] - Use consistent means of measuring time </li> </ul>

The MongoDB Node.js team is pleased to announce version 3.5.8 of the driver

Release Highlights

Fixes for NEAREST latency window calculation

@adityapatadia helped uncover an issue with our server selection logic which filtered out servers after evaluating whether they were in the latency window. This meant that non-viable servers were considered during the window calculation and would render certain viable servers unviable.

BulkWriteError writeErrors property

@vkarpov15 submitted a patch to always include writeErrors on a BulkWriteError. We have logic to set the message of BulkWriteError to the message of the first error encountered if there is only one error. Unfortunately, this logic removed the writeErrors field when doing that, so users could be faced with an error which conditionally changed shape.

Memory leak in timed out wait queue members

@dead-horse identified a memory leak in the new connection pool where wait queue members which timed out might be left in the queue indefinitely under sufficient load. The fix here was to ensure that all wait queue members are flushed during wait queue processing before evaluating whether there were available sockets to process new requests.

Implicit sessions cleanup improvements

Once @dead-horse was able to patch the connection pool memory leak, they also identified a edge case where implicit sessions could be leaked in a very specific error condition. The logic to release implicit sessions was simplified, preventing this from happening in the future

Unordered bulk writes continue-on-error

A bug introduced last summer prevented unordered bulk write operations from continuing after the first write error - one of the most important features of being an unordered operation. We now properly support this feature again.

journal in connection string is ignored

@nknighter filed a report that the journal option was ignored when provided via the connection string. The paramater j was supported both through the connection string and explicit added to MongoClient options, but the official documentation for connection strings support a journal option.

Documentation

Reference: http://mongodb.github.io/node-mongodb-native/3.5/ API: http://mongodb.github.io/node-mongodb-native/3.5/api/ Changelog: https://github.com/mongodb/node-mongodb-native/blob/3.5/HISTORY.md

We invite you to try the driver immediately, and report any issues to the NODE project.

Thanks very much to all the community members who contributed to this release!

Release Notes

<h3> Bug </h3> <ul> <li>[<a href='https://jira.mongodb.org/browse/NODE-2407'>NODE-2407</a>] - UnifiedTopology + near read makes application crash with timeout error when one of replica server is down </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2413'>NODE-2413</a>] - The node process enters an infinite loop at the pool and causes OOM </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2442'>NODE-2442</a>] - journal=true is ignored in connection string </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2548'>NODE-2548</a>] - Change streams do not resume from errors </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2565'>NODE-2565</a>] - Change stream should not check for NonResumableChangeStreamError label </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2619'>NODE-2619</a>] - Unordered bulk write aborts on first encountered error </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2625'>NODE-2625</a>] - BulkWriteError should always have a writeErrors field </li> </ul>

<h3> Task </h3> <ul> <li>[<a href='https://jira.mongodb.org/browse/NODE-2478'>NODE-2478</a>] - Use white list for change stream resumability </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2598'>NODE-2598</a>] - Change stream close refactor </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2605'>NODE-2605</a>] - Refactor shared test helpers to improve usability </li> </ul>

<h3> Improvement </h3> <ul> <li>[<a href='https://jira.mongodb.org/browse/NODE-2522'>NODE-2522</a>] - Remove ElectionInProgress (216) from ResumableChangeStreamError </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2571'>NODE-2571</a>] - Don't use admin database for FLE tests </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2630'>NODE-2630</a>] - Simplify code path for ending implicit sessions in cursors </li> </ul>

The MongoDB Node.js team is pleased to announce version 3.5.7 of the driver

Release Highlights

Warning: Accessing non-existent property 'count' of module exports inside circular dependency

Work earlier this year left some dead code in our operations code, resulting in this warning message reported by multiple users. While we still have a few cycles in our codebase yet, this will quiet Node.js 14's circular dependency warnings.

Sessions are only acquired when operations are executed

Drivers use an implicit session for all operations where an explicit session is not provided. A subtle bug was introduced when session support was implemented where implicit sessions were created and assigned to operations even if they were about to sit in a queue waiting for execution. This results in the driver creating many sessions rather than reusing pooled ones. The fix is to ensure a session is only checked out of the pool when the operation is about to be written to a server.

Thanks very much to all the community members who contributed to this release!

Release Notes

<h2> Bug </h2> <ul> <li>[<a href='https://jira.mongodb.org/browse/NODE-2536'>NODE-2536</a>] - Circular dependency in Node.js 14 nightly </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2552'>NODE-2552</a>] - Server session creation grows unbounded with every operation call </li> </ul>

<h2> Improvement </h2> <ul> <li>[<a href='https://jira.mongodb.org/browse/NODE-2534'>NODE-2534</a>] - Document options supported by the unified topology </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2560'>NODE-2560</a>] - Make 'reIndex' a standalone-only command </li> </ul>

The MongoDB Node.js team is pleased to announce version 3.5.6 of the driver

Release Highlights

Regression in map when cursor used as a stream

@dobesv helped identify a regression where a map function would be applied twice if defined on a cursor, and that cursor was used to stream data.

TypeError: Cannot read property 'code' of undefined

User @linus-hologram originally reported an issue with a TypeError when the lambda passed to the withTransaction helper rejected with a null value. @vkarpov15 submitted the fix.

readPreferenceTags interpreted as an array

A bug was fixed where readPreferenceTags with a single value in the connection string was not properly interpreted as an array of tags. This prevented the Use Analytics Nodes to Isolate Workload guidance from working correctly.

Cannot set property 'isDirty' of null

User @sean-daley reported seeing this in an AWS Lambda environment, but has proven to be somewhat of a heisenbug. We are rolling out a fix here that ensures sessions (implicit or not) are not used after they have been explicitly ended.

Thanks very much to all the community members who contributed to this release!

Release Notes

<h3> Bug </h3> <ul> <li>[<a href='https://jira.mongodb.org/browse/NODE-2503'>NODE-2503</a>] - Cursor ReadStream applies map function twice </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2515'>NODE-2515</a>] - TypeError when transaction is rejected with empty reason </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2541'>NODE-2541</a>] - readPreferenceTags are not interpreted as an array </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2545'>NODE-2545</a>] - Cannot set property 'isDirty' of null </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2549'>NODE-2549</a>] - Unknown topology should return empty array for server selection with read preference </li> </ul>

The MongoDB Node.js team is pleased to announce version 3.5.5 of the driver

Release Highlights

Regression in hasNext when using a cursor with a limit

@peterbroadhurst helped point out a regression introduced in v3.5.4 where using hasNext on a cusor with a limit would not return the full set of results.

Ignored topology updates cause servers to fall out of latency window

A change introduced across all MongoDB drivers, and in particular v3.5.0 of the Node.js driver, attempted to prevent needless duplicate topologyDescriptionChanged topology events by introducing a ServerDescription equality operator. Since equality does not take the lastUpdateTime and lastWriteDate fields of an ismaster into account, the driver could eventually consider servers non-suitable for server selection, since they would fall out of the latency window. All updates are considered viable for topology updates now, and only event emission is gated by ServerDescription equality.

Memory leaks with Node.js v12+

The legacy topology types (in particular if you were connected to a replic set) used a custom Timeout class to wrap a timer. Unfortunately, the class depended on an undocumented, private variable _called, which was removed in Node.js v12. This would lead to the driver thinking the timeout never occurred, and therefore never releasing the object for garbage collection. We recommend users of the legacy topology types immediately update to this version of the driver, or use the Unified Topology which is unaffected by this bug.

TypeError: Cannot read property 'Symbol(cancelled)' of undefined

@erfanium and @Paic helped us identify an issue in rare failover events where multiple requests to process the server selection queue would result in an attempted property access of an undefined variable.

promiseLibrary not respected by newly introduced maybePromise helper

@tobyealden pointed out that an internal refactor to use a helper to optionally return a Promise for top level API methods was not, in fact, using a custom promise library if one was provided!

Thanks very much to all the community members who contributed to this release!

Release Notes

<h3> Bug </h3> <ul> <li>[<a href='https://jira.mongodb.org/browse/NODE-2460'>NODE-2460</a>] - Memory Leak with ReplSet and NodeJS v12 </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2472'>NODE-2472</a>] - TypeError on server available with useUnifiedTopology: true </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2474'>NODE-2474</a>] - Server_Description update with lastUpdateTime / lastWriteDate fields is ignored in topology </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2480'>NODE-2480</a>] - TypeError after reconnecting </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2483'>NODE-2483</a>] - Regression using hasNext on cursor with limit </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2490'>NODE-2490</a>] - promiseLibrary option is not honoured </li> </ul>

The MongoDB Node.js team is pleased to announce version 3.5.4 of the driver

Release Highlights

Regression in hasNext when piping a cursor

Pierre Mallet and @Sintendo helped identify a regression with our cursors which did not properly rewind a cursor when hasNext was called before the cursor was piped.

Regression in server selection queue processing

A change introduced in v3.5.3 converted the server selection loop from a loop with timers to a queue of callbacks. A subtle bug was introduced to the code to process the quere where the upper bound of a for loop was using a dynamically decreasing length, leading to some operations being ignored, and ultimately timing out. Many thanks to Frederic Maillasson, @paulrobinson, and @adityapatadia for helping uncover this issue

Only ensure minimum connection pool size if a size is specified

User @millerick submitted a PR short circuiting the background task for ensuring a minimum pool size if no minimum size was set.

Release Notes

<h3> Bug </h3> <ul> <li>[<a href='https://jira.mongodb.org/browse/NODE-2454'>NODE-2454</a>] - Cursor.hasNext() seems to consume first document when the cursor is piped in a writable stream </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2464'>NODE-2464</a>] - max election ID comparison uses invalid comparison for tracking </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2466'>NODE-2466</a>] - Driver does not seem to properly recover from a long disconnection with primary server </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2467'>NODE-2467</a>] - MongoServerSelectionError when using useUnifiedTopology: true </li> </ul>

<h3> Improvement </h3> <ul> <li>[<a href='https://jira.mongodb.org/browse/NODE-2459'>NODE-2459</a>] - Do not run minimum connection size task if there is no minimum pool size </li> </ul>

The MongoDB Node.js team is pleased to announce version 3.5.3 of the driver

Release Highlights

This patch release fixes one issue with command error handling during network errors, and one minor issue with multiple incoming wire messages not being properly processed.

Release Notes

<h3> Bug </h3> <ul> <li>[<a href='https://jira.mongodb.org/browse/NODE-2435'>NODE-2435</a>] - Unified topology does not transition server to Unknown on non-timeout operation error </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2437'>NODE-2437</a>] - Multiple incoming message packets are not processed correctly </li> </ul>

<h3> Improvement </h3> <ul> <li>[<a href='https://jira.mongodb.org/browse/NODE-2438'>NODE-2438</a>] - Add exhaust command support to transport layer </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2449'>NODE-2449</a>] - Simplify server error handling in unified topology </li> </ul>

The MongoDB Node.js team is pleased to announce version 3.5.2 of the driver

Release Highlights

This patch release corrects a regression introduced in the 4.2 timeframe which would effectively disable retryable operations for connection to MongoDB 4.2+. Additionally, the server selection loop has been converted to a queue of callbacks to improve readability, as well as performance in certain scenarios.

Release Notes

<h3> Bug </h3> <ul> <li>[<a href='https://jira.mongodb.org/browse/NODE-2408'>NODE-2408</a>] - retryWrites seems not to work as expected in failover test </li> </ul>

<h3> Improvement </h3> <ul> <li>[<a href='https://jira.mongodb.org/browse/NODE-2398'>NODE-2398</a>] - Use a queue for server selection </li> </ul>

The MongoDB Node.js team is pleased to announce version 3.5.1 of the driver

Release Highlights

This patch release fixes a few regressions introduced with new connection pool, primarily around the ability to use custom TLS certificates.

Release Notes

<h3> Bug </h3> <ul> <li>[<a href='https://jira.mongodb.org/browse/NODE-2372'>NODE-2372</a>] - db.findOne does not respect client setting bufferMaxEntries </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2401'>NODE-2401</a>] - "readPreference.equals is not a function" exception thrown within executeWithServerSelection </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2424'>NODE-2424</a>] - CMAP connection pool fails to create connection using SSL / TLS </li> </ul>

The MongoDB Node.js team is pleased to announce version 3.5.0 of the driver

Release Highlights

CMAP-compliant Connection Pool

This release introduces a modern replacement for the driver's connection pool, available only with the unified topology. A major effort was made in early 2019 to fully specifiy connection pools for MongoDB drivers (see: CMAP specification), and this release brings the Node.js driver in line with that specification.

Traceability

The new pool supports monitoring for all aspects of its behavior. This allows deep introspection into the operation of the connection pool, as well as an ability to profile the lifetime of an operation when used in conjunction with command monitoring.

Stream-first Connection Design

The Connection class was completely rewritten for the new pool adopting a stream-first mentality. All wire message processing and compression is handled in a duplex stream called the MessageStream, and that stream is connected bidirectionally to the underlaying TCP socket. The result is a connection which gains the general benefit of streams: better performance, less memory pressure, backpressure support. It also opens the possiblity of supporting non-TCP/UDP streams as a transport for the driver.

waitQueueTimeoutMS

The new connection pool has a concept of a "wait queue", which allows operation requests to buffer waiting for a connection to execute against. There is no timeout by default, but users can now specify a new value waitQueueTimeoutMS in their connection string or MongoClient options to proactively cancel operations that have waited too long.

Remember that the new connection pool is only available for the "Unified Topology", so remember to pass useUnifiedTopology: true to your MongoClient constructor to use it!

Dedicated monitoring connection

Both the legacy and unified SDAM implementations have until now executed monitoring checks as priority messages in the legacy Pool implementation. This means that monitoring (ismaster) operations were prioritized over other queued operations, but also means that monitoring could be indefinitely blocked, in particular during failover or black hole scenarios. The default socket timeout is null (read: Infinity), so if the pool was completely saturated with operations, there may be no ability to execute a monitoring check and determine that the connection to a server was no longer valid. This version of the driver introduces a new Monitor class which manages its own dedicated monitoring connection to each known node.

Server selection errors

In v3.3.0 of the driver we introduced a new MongoTimeoutError for all errors covered by the server selection loop, leading to a spike in bug reports with a title similar to Server selection timed out after 30000ms. Even though the error type itself had an attached reason field, we still feel it was easy to miss why the selection had failed. As a result we have introduced a new type MongoServerSelectionError which will use the originating error (reason) for its message, better informing users what caused a selection error, while still also conveying it is an error in server selection.

Release Notes

<h3> New Feature </h3> <ul> <li>[<a href='https://jira.mongodb.org/browse/NODE-1742'>NODE-1742</a>] - Implement Connection Monitoring and Pooling spec </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2386'>NODE-2386</a>] - Use a dedicated monitoring thread </li> </ul>

<h3> Bug </h3> <ul> <li>[<a href='https://jira.mongodb.org/browse/NODE-2400'>NODE-2400</a>] - Synchronous errors are swallowed by executeOperation </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2417'>NODE-2417</a>] - Server descriptions with me mismatch from primary response should be removed </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2418'>NODE-2418</a>] - client platform not sent in metadata for CMAP connections </li> </ul>

<h3> Improvement </h3> <ul> <li>[<a href='https://jira.mongodb.org/browse/NODE-1619'>NODE-1619</a>] - Remove wasteful empty Buffer allocations in Connection </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2049'>NODE-2049</a>] - Add "connectionError" as a valid "reason" for a ConnectionCheckOutFailedEvent when connection set up fails </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2397'>NODE-2397</a>] - Make server selection errors more informative </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2402'>NODE-2402</a>] - Integrate CMAP connection pool into unified topology </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2419'>NODE-2419</a>] - Improve traceability of CMAP events </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2033'>NODE-2033</a>] - Ignore ConnectionReadyEvent in CMAP pool creation test </li> </ul>

The MongoDB Node.js team is pleased to announce version 3.4.1 of the driver

Release Highlights

This is a patch release addressing two regressions introduced in bulk writes and SCRAM authentication.

Release Notes

<h2> Bug </h2> <ul> <li>[<a href='https://jira.mongodb.org/browse/NODE-2383'>NODE-2383</a>] - Unordered bulk write reports wrong error indexes </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2390'>NODE-2390</a>] - Sporadic connection errors with AWS Lambda </li> </ul>

The MongoDB Node.js team is pleased to announce version 3.4.0 of the driver

Release Highlights

Client Side Field Level Encryption (CSFLE)

The major functionality introduced in this release, and indeed the reason for the minor version bump, is full support for MongoDB's Client Side Field Level Encryption. The bulk of the support comes through an addon module mongodb-client-encryption, please refer to the reference documentation for more details.

TLS Option Variants

This release also introduces a number of new connection string options related to TLS. In order to unify uri options across all MongoDB drivers, and to better signal the technology the driver is actually using, all ssl related options now have a corresponding tls variant. NOTE: your application will not break if you continue to use the ssl variants, but deprecation warnings will be introduced prior to the 4.x driver release.

@adityapatadia initially pointed out that these tls variants had no effect, now they do. Thank you @adityapatadia!

mongodb+srv

A critical bug was found by @ephemer with the recently introduced "mongos discovery", where a typo caused DNS polling to occur at very fast intervals.

Additionally, user @mpilar identified and fixed a bug with our mongodb+srv parsing, where user-provided client options were not overriding those provided by a TXT record lookup.

Thank you very much @ephemer and @mpilar!

server selection

@adityapatadia also helped find a bug in the server selection code which rendered selection with a nearest read preference non-functional. Thanks again @adityapatadia!

bulkWrite

A small bug was fixed causing errors in an unordered bulk write to be reported in incorrect order. If an error occurs in a bulk write now, then it will show up in the writeErrors field of the resulting BulkWriteError with an index that corresponds to the position the operation had in the initial input.

Release Notes

<h2> Bug </h2> <ul> <li>[<a href='https://jira.mongodb.org/browse/NODE-1547'>NODE-1547</a>] - Default Port is not applied </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-1991'>NODE-1991</a>] - replaceOne() also returns the replacement document? </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2089'>NODE-2089</a>] - Only apply TransientTransactionError label within a transaction </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2308'>NODE-2308</a>] - Bulk write error returns incorrect index in WriteError for unordered writes </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2334'>NODE-2334</a>] - Driver must error if autoEncryption is attempted against wire version < 8 </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2335'>NODE-2335</a>] - Node Driver does not follow Initial DNS Seedlist Discovery spec </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2353'>NODE-2353</a>] - Timed out connections should not half-close on destroy </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2356'>NODE-2356</a>] - nearest server is not selected when useUnifiedTopology is set </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2359'>NODE-2359</a>] - tls option in connection URI has no effect </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2375'>NODE-2375</a>] - Typo in rescanIntervalSrvMS causes spike in DNS lookups </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2376'>NODE-2376</a>] - Malicious server can accept incomplete SCRAM authentication and bypass mutual authentication </li> </ul>

<h2> New Feature </h2> <li>[<a href='https://jira.mongodb.org/browse/NODE-2094'>NODE-2094</a>] - FLE GA Support </li> <ul> </ul>

<h2> Improvement </h2> <ul> <li>[<a href='https://jira.mongodb.org/browse/NODE-2024'>NODE-2024</a>] - Document createIndexes usage </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2052'>NODE-2052</a>] - [FLE] Add a corpus test that exhaustively enumerates all ways to encrypt all BSON value types </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2053'>NODE-2053</a>] - [FLE] Add prose test for explicit encryption with key alt name </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2298'>NODE-2298</a>] - Add driver API documentation for Field Level Encryption </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2363'>NODE-2363</a>] - Allow connection establishment to be cancelled </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2306'>NODE-2306</a>] - Driver module does not export BulkWriteError </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2338'>NODE-2338</a>] - build FLE addon on windows </li> </ul>

The MongoDB Node.js team is pleased to announce version 3.3.5 of the driver

Release Highlights

unified topology

This patch release includes additional fixes for the regression in the unified topology discovered in v3.3.2, expanding our testing infrastructure to include a simulated workload during failover testing. There was a bug when connecting to single-node replicasets which could result in a stack overflow which was corrected. Additionally, events and options which are incompatible with the unified topology will now emit a warning message.

mongodb+srv

The release also includes a fix submitted by @mpilar, who found an inconsistency in our implementation of the "Initial Seedlist Discovery" specification. An authSource specified in the options passed to MongoClient would be overridden by an authSource provided in the TXT record checked during initial seedlist discovery over SRV. Thank you very much Miguel!

bulkWrite

BulkWriteError is now exported at the top level of the module so that users can catch them easily. Additionally, a fix was made to ensure that the index of operations passed into an unordered bulk operation were preserved when reporting possible errors in the future.

Release Notes

<h2> Bug </h2> <ul> <li>[<a href='https://jira.mongodb.org/browse/NODE-1747'>NODE-1747</a>] - Replica set causes MongoNetworkError due to not connecting with fully qualified domain name </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2089'>NODE-2089</a>] - Only apply TransientTransactionError label within a transaction </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2143'>NODE-2143</a>] - getaddrinfo ENOTFOUND error on Windows 10 due to failed fallback to ipv4 after ipv6 lookup fails </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2308'>NODE-2308</a>] - Bulk write error returns incorrect index in WriteError for unordered writes </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2332'>NODE-2332</a>] - useUnifiedTopology - replicaset </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2335'>NODE-2335</a>] - Node Driver does not follow Initial DNS Seedlist Discovery spec </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2342'>NODE-2342</a>] - Enabling useUnifiedTopology results in stack overflow when connecting to uninitialized replica set </li> </ul>

<h2> Improvement </h2> <ul> <li>[<a href='https://jira.mongodb.org/browse/NODE-2348'>NODE-2348</a>] - Document and notify on deprecated events and options for unified topology </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2306'>NODE-2306</a>] - Driver module does not export BulkWriteError </li> </ul>

The MongoDB Node.js team is pleased to announce version 3.3.4 of the driver

Release Highlights

This release primary consists of improvements to the "unified topology". In particular, a regression with interaction between the connection pool and topology could result in servers which "go away" (due to network error, for example) would not return, resulting in a MongoTimeoutError.

Release Notes

<h2> Bug </h2> <ul> <li>[<a href='https://jira.mongodb.org/browse/NODE-2123'>NODE-2123</a>] - MaxListenersExceededWarning caused by topologyDescriptionChanged </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2214'>NODE-2214</a>] - Incorrect removal of Unknown server type from ReplicaSetNoPrimary topology </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2234'>NODE-2234</a>] - isConnected() takes legacy path with useUnifiedTopology </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2251'>NODE-2251</a>] - useUnifiedTopology continuously emits 'close' event when replica set member is down </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2268'>NODE-2268</a>] - Legacy SDAM ReplSet topology reports incorrect topology ID </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2270'>NODE-2270</a>] - Servers are not removed from unknownServer list, leaking </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2274'>NODE-2274</a>] - Unified topology never regains nodes which temporarily go down </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2277'>NODE-2277</a>] - Unhandled error when server is offline </li> </ul>

<h2> Improvement </h2> <ul> <li>[<a href='https://jira.mongodb.org/browse/NODE-1517'>NODE-1517</a>] - normalize state management across all stateful types </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2257'>NODE-2257</a>] - Introduce ServerDescription equality to reduce SDAM events </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2263'>NODE-2263</a>] - support ability to pass hint to update </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2276'>NODE-2276</a>] - Add SDAM test for debouncing topology description updates </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2280'>NODE-2280</a>] - Integrate a state machine into the unified topology </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2309'>NODE-2309</a>] - Document the design and rationale of the unified topology </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2316'>NODE-2316</a>] - Correct client metadata for unified topology </li> </ul>

The MongoDB Node.js team is pleased to announce version 3.3.0 of the driver

Release Highlights

Server Version 4.2 feature support

This latest release brings support for features in the newly released MongoDB v4.2:

• Distributed Transactions
• On-Demand Materialized Views with the $merge operator
• Wildcard Indexes
• Retryable Reads
• MongoDB Query Language Enhancements.

SRV Polling for Sharded Clusters

The Driver has supported connecting to a cluster using an SRV record since version 3.0. Prior to now, we would only resolve the SRV record when initially connecting. This was fine for single replica sets, as the driver is able to discover new members added after initial connect from any member of a replica set. However, in a sharded deployment, individual mongos processes do not have an awareness of each other. This means that if the deployment changes in a shared cluster, the driver would have no way of knowing without disconnecting and connecting with a new client.

Starting in 3.3, if a driver connects to a sharded cluster with an SRV record, we will now periodically check that SRV record for any changes in the deployment, and update the client-side connections accordingly.

**NOTE: This feature is only available when starting a client with { useUnifiedTopology: true } **

Beta support for MongoDB Client-Side Encryption

The driver now has support for MongoDB Client-Side Encryption. This requires installing the mongodb-client-encryption npm package in your project.

Merged mongodb-core into node-mongodb-native

Up until this release, the mongodb driver has consisted of two components:

• mongodb-core: The low-level engine of the driver.
• node-mongodb-native: The API layer of the driver, published as mongodb

Over time, this separation has done more harm than good, and has led to increased development time for repairing bugs and implementing new features. Starting in the 3.3 release of mongodb, we have merged mongodb-core into node-mongodb-native, removing this barrier to development.

Release Notes

<h3> Bug </h3> <ul> <li>[<a href='https://jira.mongodb.org/browse/NODE-1480'>NODE-1480</a>] - 'Should handle Error thrown during operation' in error_tests.js should handle exception </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-1994'>NODE-1994</a>] - fix 'should correctly handle multiple unordered batch API' </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2022'>NODE-2022</a>] - startAtOperationTime and resumeToken conflict on cursor restarts </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2051'>NODE-2051</a>] - MongoClient with autoEncryption does not clean up MongoCryptD client </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2054'>NODE-2054</a>] - [FLE] AutoEncrypter MongoClient does not use new url parser </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2060'>NODE-2060</a>] - can't use database named 'constructor' </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2067'>NODE-2067</a>] - requestid overflow </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2075'>NODE-2075</a>] - Ensure error events also emit close events in change_stream.js </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2077'>NODE-2077</a>] - Invalid staleness calculation </li> </ul>

<h3> Epic </h3> <ul> <li>[<a href='https://jira.mongodb.org/browse/NODE-1405'>NODE-1405</a>] - Improve command construction </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-1744'>NODE-1744</a>] - Retryable Reads </li> </ul>

<h3> New Feature </h3> <ul> <li>[<a href='https://jira.mongodb.org/browse/NODE-1740'>NODE-1740</a>] - Implement Unified URI Options </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-1745'>NODE-1745</a>] - Support polling SRV records for mongos discovery </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-1750'>NODE-1750</a>] - Connections survive primary stepdown </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-1766'>NODE-1766</a>] - Aggregate command must be sent to a primary if it uses $out </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-1820'>NODE-1820</a>] - Resync CRUD spec tests to use transaction spec test format </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-1824'>NODE-1824</a>] - Support 'startAfter' option to the $changeStream stage </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-1864'>NODE-1864</a>] - Support Retryable Writes on by Default </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-1866'>NODE-1866</a>] - Support postBatchResumeToken in change streams </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-1880'>NODE-1880</a>] - Add support for majority read concern level to Aggregation $out </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-1896'>NODE-1896</a>] - Implement executeOperationV2 </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-1902'>NODE-1902</a>] - Add "aspects" to all operation classes </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-1920'>NODE-1920</a>] - Add the ability to specify a pipeline to an update command </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-1931'>NODE-1931</a>] - Ensure 4.0 drivers return an error when attempting sharded transactions on 4.2 </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-1965'>NODE-1965</a>] - More useful error when bulk writes fail </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2023'>NODE-2023</a>] - set default for useRecoveryToken to true </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2071'>NODE-2071</a>] - [FLE]: use crypto callbacks </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2078'>NODE-2078</a>] - Improve error message for missing mongodb-client-encryption </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2095'>NODE-2095</a>] - Operating System Removals/Updates for 4.2 </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2098'>NODE-2098</a>] - Raise an actionable error message when retryWrites fails due to using an unsupported storage engine </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2102'>NODE-2102</a>] - Mark the FLE feature as "Beta" in driver docs </li> </ul>

<h3> Task </h3> <ul> <li>[<a href='https://jira.mongodb.org/browse/NODE-1854'>NODE-1854</a>] - POC - Support Client-side Field Level Encryption </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-1949'>NODE-1949</a>] - Add tests for postBatchResumeToken support </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-1950'>NODE-1950</a>] - Test writes in transactions do not send writeConcern when collection write concern is w=0 </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-1951'>NODE-1951</a>] - Amend change stream missing resume token tests for wire version 8+ </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-1966'>NODE-1966</a>] - Merge core and native modules into a single driver </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-1979'>NODE-1979</a>] - Clarify resume token used in resuming and getResumeToken </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2004'>NODE-2004</a>] - Spec: Finer-grained updates from aggregation via $merge </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2017'>NODE-2017</a>] - Fix result assertion in change stream spec test </li> </ul>

<h3> Improvement </h3> <ul> <li>[<a href='https://jira.mongodb.org/browse/NODE-1425'>NODE-1425</a>] - validate internal representation of ReadPreference </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-1557'>NODE-1557</a>] - Clean up constructor for ClientSession </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-1682'>NODE-1682</a>] - Implement connection pool reset </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-1756'>NODE-1756</a>] - applyWriteConcern should take a writeConcern </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-1811'>NODE-1811</a>] - Refactor readconcern tests </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-1897'>NODE-1897</a>] - Move all operations to their own classes </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-1910'>NODE-1910</a>] - Refactor findAnd* operations to extend findAndModify </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-1943'>NODE-1943</a>] - Move executeOperation to executeLegacyOperation </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-1944'>NODE-1944</a>] - Use new CommandOperation for operations </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-1947'>NODE-1947</a>] - create a MongoNamespace for database and collection classes </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-1962'>NODE-1962</a>] - Remove duplicate operation code </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-1976'>NODE-1976</a>] - ChangeStream spec's Resumable Error definition is too broad </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-1977'>NODE-1977</a>] - Discard ServerSessions involved in network errors </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2016'>NODE-2016</a>] - Test MongoDB 4.2 in Evergreen </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2025'>NODE-2025</a>] - Fix Node is Recovering error handling </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2063'>NODE-2063</a>] - Simplify cursor constructor </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2064'>NODE-2064</a>] - Use AggregateOperation for aggregation cursors </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2065'>NODE-2065</a>] - Simplify cursor session management </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2066'>NODE-2066</a>] - Cursor should use wire protocol primitives on stored server </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2068'>NODE-2068</a>] - Perform server selection for sessions check if required </li> <li>[<a href='https://jira.mongodb.org/browse/NODE-2079'>NODE-2079</a>] - Add attribute fullResponse to CommandOperationV2 </li> </ul>