2021-05-11, Version 14.17.0 Fermium (LTS)

Notable changes:

Diagnostics channel (experimental module):

`diagnostics_channel` is a new experimental module that provides an API to create named channels to report arbitrary message data for diagnostics purposes.

The module was initially introduced in Node.js v15.1.0 and is backported to v14.17.0
to enable testing it at a larger scale.

With `diagnostics_channel`, Node.js core and module authors can publish contextual data about what they are doing at a given time. This could be the hostname and query string of a mysql query, for example. Just create a named channel with `dc.channel(name)` and call `channel.publish(data)` to send the data to any listeners to that channel.

```js
const dc = require('diagnostics_channel');
const channel = dc.channel('mysql.query');

MySQL.prototype.query = function query(queryString, values, callback) {
  // Broadcast query information whenever a query is made
  channel.publish({
    query: queryString,
    host: this.hostname,
  });

  this.doQuery(queryString, values, callback);
};
```

Channels are like one big global event emitter but are split into separate objects to ensure they get the best performance. If nothing is listening to the channel, the publishing overhead should be as close to zero as possible. Consuming channel data is as easy as using `channel.subscribe(listener)` to run a function whenever a message is published to that channel.

```js
const dc = require('diagnostics_channel');
const channel = dc.channel('mysql.query');

channel.subscribe(({ query, host }) => {
  console.log(`mysql query to ${host}: ${query}`);
});
```

The data captured can be used to provide context for what an app is doing at a given time. This can be used for things like augmenting tracing data, tracking network and filesystem activity, logging queries, and many other things. It's also a very useful data source for diagnostics tools to provide a clearer picture of exactly what the application is doing at a given point in the data they are presenting.

Contributed by Stephen Belanger (#34895).

UUID support in the crypto module:

The new `crypto.randomUUID()` method now allows to generate random
[RFC 4122](https://www.rfc-editor.org/rfc/rfc4122.txt) Version 4 UUID strings:

```js
const { randomUUID } = require('crypto');

console.log(randomUUID());
// 'aa7c91a1-f8fc-4339-b9db-f93fc7233429'
```

Contributed by James M Snell (#36729.

Experimental support for `AbortController` and `AbortSignal`:

Node.js 14.17.0 adds experimental partial support for `AbortController` and `AbortSignal`.

Both constructors can be enabled globally using the `--experimental-abortcontroller` flag.

Additionally, several Node.js APIs have been updated to support `AbortSignal` for cancellation.
It is not mandatory to use the built-in constructors with them. Any spec-compliant third-party alternatives
should be compatible.

`AbortSignal` support was added to the following methods:

* `child_process.exec`
* `child_process.execFile`
* `child_process.fork`
* `child_process.spawn`
* `dgram.createSocket`
* `events.on`
* `events.once`
* `fs.readFile`
* `fs.watch`
* `fs.writeFile`
* `http.request`
* `https.request`
* `http2Session.request`
* The promisified variants of `setImmediate` and `setTimeout`

Other notable changes:

* doc:
  * revoke deprecation of legacy url, change status to legacy (James M Snell) (#37784)
  * add legacy status to stability index (James M Snell) (#37784)
  * upgrade stability status of report API (Gireesh Punathil) (#35654)
* deps:
  * V8: Backport various patches for Apple Silicon support (BoHong Li) (#38051)
  * update ICU to 68.1 (Michaël Zasso) (#36187)
  * upgrade to libuv 1.41.0 (Colin Ihrig) (#37360)
* http:
  * add http.ClientRequest.getRawHeaderNames() (simov) (#37660)
  * report request start and end with diagnostics\_channel (Stephen Belanger) (#34895)
* util:
  * add getSystemErrorMap() impl (eladkeyshawn) (#38101)

PR-URL: #38507

doc/api/buffer.md

@@ -3114,7 +3114,7 @@ accessed using `require('buffer')`.
 
 ### `buffer.atob(data)`
 <!-- YAML
-added: REPLACEME
+added: v14.17.0
 -->
 
 * `data` {any} The Base64-encoded input string.
@@ -3133,7 +3133,7 @@ and binary data should be performed using `Buffer.from(str, 'base64')` and
 
 ### `buffer.btoa(data)`
 <!-- YAML
-added: REPLACEME
+added: v14.17.0
 -->
 
 * `data` {any} An ASCII (Latin1) string.

doc/api/child_process.md

@@ -250,7 +250,7 @@ lsExample();
 <!-- YAML
 added: v0.1.91
 changes:
-  - version: REPLACEME
+  - version: v14.17.0
     pr-url: https://github.com/nodejs/node/pull/36308
     description: AbortSignal support was added.
   - version: v8.8.0
@@ -351,7 +351,7 @@ controller.abort();
 <!-- YAML
 added: v0.5.0
 changes:
-  - version: REPLACEME
+  - version: v14.17.0
     pr-url: https://github.com/nodejs/node/pull/36603
     description: AbortSignal support was added.
   - version:
@@ -431,7 +431,7 @@ The `signal` option works exactly the same way it does in
 <!-- YAML
 added: v0.1.90
 changes:
-  - version: REPLACEME
+  - version: v14.17.0
     pr-url: https://github.com/nodejs/node/pull/36432
     description: AbortSignal support was added.
   - version:
@@ -1086,7 +1086,7 @@ See [Advanced serialization][] for more details.
 
 ### Event: `'spawn'`
 <!-- YAML
-added: REPLACEME
+added: v14.17.0
 -->
 
 The `'spawn'` event is emitted once the child process has spawned successfully.

doc/api/cli.md

@@ -199,7 +199,7 @@ Currently, overriding `Error.prepareStackTrace` is ignored when the
 
 ### `--experimental-abortcontroller`
 <!-- YAML
-added: REPLACEME
+added: v14.17.0
 -->
 
 Enable experimental `AbortController` and `AbortSignal` support.

doc/api/crypto.md

@@ -2843,7 +2843,7 @@ console.log(`The dice rolled: ${n}`);
 
 ### `crypto.randomUUID([options])`
 <!-- YAML
-added: REPLACEME
+added: v14.17.0
 -->
 
 * `options` {Object}

doc/api/deprecations.md

@@ -2148,7 +2148,7 @@ future release.
 ### DEP0116: Legacy URL API
 <!-- YAML
 changes:
-  - version: REPLACEME
+  - version: v14.17.0
     pr-url: https://github.com/nodejs/node/pull/37784
     description: Deprecation revoked. Status changed to "Legacy".
   - version: v11.0.0

doc/api/diagnostics_channel.md

@@ -1,6 +1,6 @@
 # Diagnostics Channel
 
-<!--introduced_in=REPLACEME-->
+<!--introduced_in=v14.17.0-->
 
 > Stability: 1 - Experimental
 

doc/api/dns.md

@@ -119,7 +119,7 @@ callbacks will be called with an error with code `ECANCELLED`.
 
 ### `resolver.setLocalAddress([ipv4][, ipv6])`
 <!-- YAML
-added: REPLACEME
+added: v14.17.0
 -->
 
 * `ipv4` {string} A string representation of an IPv4 address.
@@ -437,7 +437,7 @@ will contain an array of canonical name records available for the `hostname`
 
 ## `dns.resolveCaa(hostname, callback)`
 <!-- YAML
-added: REPLACEME
+added: v14.17.0
 -->
 
 * `hostname` {string}
@@ -718,7 +718,7 @@ The following methods from the `dnsPromises` API are available:
 
 ### `resolver.cancel()`
 <!-- YAML
-added: REPLACEME
+added: v14.17.0
 -->
 
 Cancel all outstanding DNS queries made by this resolver. The corresponding
@@ -946,7 +946,7 @@ Here is an example of the result object:
 
 ### `dnsPromises.resolveCaa(hostname)`
 <!-- YAML
-added: REPLACEME
+added: v14.17.0
 -->
 
 * `hostname` {string}

doc/api/esm.md

@@ -6,7 +6,7 @@
 added: v8.5.0
 changes:
   - version:
-    - REPLACEME
+    - v14.17.0
     pr-url: https://github.com/nodejs/node/pull/35781
     description: Stabilize modules implementation.
   - version:

doc/api/events.md

@@ -385,7 +385,7 @@ regular `'error'` listener is installed.
 
 ### `EventEmitter.setMaxListeners(n[, ...eventTargets])`
 <!-- YAML
-added: REPLACEME
+added: v14.17.0
 -->
 
 * `n` {number} A non-negative number. The maximum number of listeners per
@@ -855,7 +855,7 @@ class MyClass extends EventEmitter {
 ## `events.getEventListeners(emitterOrTarget, eventName)`
 <!-- YAML
 added:
- - REPLACEME
+ - v14.17.0
 -->
 * `emitterOrTarget` {EventEmitter|EventTarget}
 * `eventName` {string|symbol}

doc/api/fs.md

@@ -1612,7 +1612,7 @@ See also: chown(2).
 <!-- YAML
 added: v0.0.2
 changes:
-  - version: REPLACEME
+  - version: v14.17.0
     pr-url: https://github.com/nodejs/node/pull/37174
     description: A default callback is now used if one is not provided.
   - version: v10.0.0
@@ -3031,7 +3031,7 @@ If `options.withFileTypes` is set to `true`, the result will contain
 <!-- YAML
 added: v0.1.29
 changes:
-  - version: REPLACEME
+  - version: v14.17.0
     pr-url: https://github.com/nodejs/node/pull/35911
     description: The options argument may include an AbortSignal to abort an
                  ongoing readFile request.
@@ -4083,7 +4083,7 @@ this API: [`fs.utimes()`][].
 <!-- YAML
 added: v0.5.10
 changes:
-  - version: REPLACEME
+  - version: v14.17.0
     pr-url: https://github.com/nodejs/node/pull/37190
     description: Added support for closing the watcher with an AbortSignal.
   - version: v7.6.0
@@ -4405,7 +4405,7 @@ details.
 <!-- YAML
 added: v0.1.29
 changes:
-  - version: REPLACEME
+  - version: v14.17.0
     pr-url: https://github.com/nodejs/node/pull/35993
     description: The options argument may include an AbortSignal to abort an
                  ongoing writeFile request.
@@ -5491,7 +5491,7 @@ print('./').catch(console.error);
 <!-- YAML
 added: v10.0.0
 changes:
-  - version: REPLACEME
+  - version: v14.17.0
     pr-url: https://github.com/nodejs/node/pull/35911
     description: The options argument may include an AbortSignal to abort an
                  ongoing readFile request.
@@ -5741,7 +5741,7 @@ The `atime` and `mtime` arguments follow these rules:
 <!-- YAML
 added: v10.0.0
 changes:
-  - version: REPLACEME
+  - version: v14.17.0
     pr-url: https://github.com/nodejs/node/pull/35993
     description: The options argument may include an AbortSignal to abort an
                  ongoing writeFile request.

doc/api/globals.md

@@ -19,7 +19,7 @@ accessible.
 
 ## Class: `AbortController`
 <!--YAML
-added: REPLACEME
+added: v14.17.0
 -->
 
 > Stability: 1 - Experimental
@@ -44,22 +44,22 @@ console.log(ac.signal.aborted);  // Prints True
 
 ### `abortController.abort()`
 <!-- YAML
-added: REPLACEME
+added: v14.17.0
 -->
 
 Triggers the abort signal, causing the `abortController.signal` to emit
 the `'abort'` event.
 
 ### `abortController.signal`
 <!-- YAML
-added: REPLACEME
+added: v14.17.0
 -->
 
 * Type: {AbortSignal}
 
 ### Class: `AbortSignal`
 <!-- YAML
-added: REPLACEME
+added: v14.17.0
 -->
 
 * Extends: {EventTarget}
@@ -69,7 +69,7 @@ The `AbortSignal` is used to notify observers when the
 
 #### Static method: `AbortSignal.abort()`
 <!-- YAML
-added: REPLACEME
+added: v14.17.0
 -->
 
 * Returns: {AbortSignal}
@@ -78,7 +78,7 @@ Returns a new already aborted `AbortSignal`.
 
 #### Event: `'abort'`
 <!-- YAML
-added: REPLACEME
+added: v14.17.0
 -->
 
 The `'abort'` event is emitted when the `abortController.abort()` method
@@ -112,14 +112,14 @@ result in memory leaks.
 
 #### `abortSignal.aborted`
 <!-- YAML
-added: REPLACEME
+added: v14.17.0
 -->
 
 * Type: {boolean} True after the `AbortController` has been aborted.
 
 #### `abortSignal.onabort`
 <!-- YAML
-added: REPLACEME
+added: v14.17.0
 -->
 
 * Type: {Function}

doc/api/http.md

@@ -113,7 +113,7 @@ http.get({
 <!-- YAML
 added: v0.3.4
 changes:
-  - version: REPLACEME
+  - version: v14.17.0
     pr-url: https://github.com/nodejs/node/pull/36685
     description: Change the default scheduling from 'fifo' to 'lifo'.
   - version: v14.5.0
@@ -758,7 +758,7 @@ const cookie = request.getHeader('Cookie');
 
 ### `request.getRawHeaderNames()`
 <!-- YAML
-added: REPLACEME
+added: v14.17.0
 -->
 
 * Returns: {string[]}
@@ -2364,7 +2364,7 @@ This can be overridden for servers and client requests by passing the
 <!-- YAML
 added: v0.3.6
 changes:
-  - version: REPLACEME
+  - version: v14.17.0
     pr-url: https://github.com/nodejs/node/pull/36048
     description: It is possible to abort a request with an AbortSignal.
   - version:

doc/api/http2.md

@@ -2,7 +2,7 @@
 <!-- YAML
 added: v8.4.0
 changes:
-  - version: REPLACEME
+  - version: v14.17.0
     pr-url: https://github.com/nodejs/node/pull/36070
     description: It is possible to abort a request with an AbortSignal.
   - version: v10.10.0
@@ -1880,7 +1880,7 @@ value only affects new connections to the server, not any existing connections.
 
 #### `server.updateSettings([settings])`
 <!-- YAML
-added: REPLACEME
+added: v14.17.0
 -->
 
 * `settings` {HTTP/2 Settings Object}
@@ -2074,7 +2074,7 @@ value only affects new connections to the server, not any existing connections.
 
 #### `server.updateSettings([settings])`
 <!-- YAML
-added: REPLACEME
+added: v14.17.0
 -->
 
 * `settings` {HTTP/2 Settings Object}

doc/api/modules.md

@@ -891,7 +891,7 @@ filename.
 
 ### `module.isPreloading`
 <!-- YAML
-added: REPLACEME
+added: v14.17.0
 -->
 
 * Type: {boolean} `true` if the module is running during the Node.js preload

doc/api/process.md

@@ -1986,7 +1986,7 @@ Additional documentation is available in the [report documentation][].
 added: v11.12.0
 changes:
   - version:
-     - REPLACEME
+     - v14.17.0
     pr-url: https://github.com/nodejs/node/pull/35654
     description: This API is no longer experimental.
 -->

doc/api/readline.md

@@ -285,7 +285,7 @@ whenever `rl.prompt()` is called.
 
 ### `rl.getPrompt()`
 <!-- YAML
-added: REPLACEME
+added: v14.17.0
 -->
 
 * Returns: {string} the current prompt string

doc/api/stream.md

@@ -576,7 +576,7 @@ the status of the `highWaterMark`.
 
 ##### `writable.writableNeedDrain`
 <!-- YAML
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+added: v14.17.0
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 * {boolean}