feat(NODE-5169): Implement emergency logger

src/cmap/command_monitoring_events.ts

@@ -1,5 +1,11 @@
 import type { Document, ObjectId } from '../bson';
-import { LEGACY_HELLO_COMMAND, LEGACY_HELLO_COMMAND_CAMEL_CASE } from '../constants';
+import {
+  COMMAND_FAILED,
+  COMMAND_STARTED,
+  COMMAND_SUCCEEDED,
+  LEGACY_HELLO_COMMAND,
+  LEGACY_HELLO_COMMAND_CAMEL_CASE
+} from '../constants';
 import { calculateDurationInMs, deepCopy } from '../utils';
 import { Msg, WriteProtocolMessageType } from './commands';
 import type { Connection } from './connection';
@@ -18,6 +24,8 @@ export class CommandStartedEvent {
   address: string;
   connectionId?: string | number;
   serviceId?: ObjectId;
+  /** @internal */
+  name = COMMAND_STARTED;
 
   /**
    * Create a started event
@@ -65,6 +73,8 @@ export class CommandSucceededEvent {
   commandName: string;
   reply: unknown;
   serviceId?: ObjectId;
+  /** @internal */
+  name = COMMAND_SUCCEEDED;
 
   /**
    * Create a succeeded event
@@ -113,6 +123,8 @@ export class CommandFailedEvent {
   commandName: string;
   failure: Error;
   serviceId?: ObjectId;
+  /** @internal */
+  name = COMMAND_FAILED;
 
   /**
    * Create a failure event

src/cmap/connect.ts

@@ -401,6 +401,7 @@ function makeConnection(options: MakeConnectionOptions, _callback: Callback<Stre
 
     if ('authorizationError' in socket) {
       if (socket.authorizationError && rejectUnauthorized) {
+        // TODO(NODE-5192): wrap this with a MongoError subclass
         return callback(socket.authorizationError);
       }
     }

src/cmap/connection_pool.ts

@@ -641,7 +641,10 @@ export class ConnectionPool extends TypedEventEmitter<ConnectionPoolEvents> {
     }
   }
 
-  private destroyConnection(connection: Connection, reason: string) {
+  private destroyConnection(
+    connection: Connection,
+    reason: 'error' | 'idle' | 'stale' | 'poolClosed'
+  ) {
     this.emit(
       ConnectionPool.CONNECTION_CLOSED,
       new ConnectionClosedEvent(this, connection, reason)
@@ -701,7 +704,13 @@ export class ConnectionPool extends TypedEventEmitter<ConnectionPoolEvents> {
         this[kPending]--;
         this.emit(
           ConnectionPool.CONNECTION_CLOSED,
-          new ConnectionClosedEvent(this, { id: connectOptions.id, serviceId: undefined }, 'error')
+          new ConnectionClosedEvent(
+            this,
+            { id: connectOptions.id, serviceId: undefined },
+            'error',
+            // TODO(NODE-5192): Remove this cast
+            err as MongoError
+          )
         );
         if (err instanceof MongoNetworkError || err instanceof MongoServerError) {
           err.connectionGeneration = connectOptions.generation;
@@ -812,7 +821,7 @@ export class ConnectionPool extends TypedEventEmitter<ConnectionPoolEvents> {
         const error = this.closed ? new PoolClosedError(this) : new PoolClearedError(this);
         this.emit(
           ConnectionPool.CONNECTION_CHECK_OUT_FAILED,
-          new ConnectionCheckOutFailedEvent(this, reason)
+          new ConnectionCheckOutFailedEvent(this, reason, error)
         );
         if (waitQueueMember.timer) {
           clearTimeout(waitQueueMember.timer);
@@ -865,7 +874,8 @@ export class ConnectionPool extends TypedEventEmitter<ConnectionPoolEvents> {
           if (err) {
             this.emit(
               ConnectionPool.CONNECTION_CHECK_OUT_FAILED,
-              new ConnectionCheckOutFailedEvent(this, 'connectionError')
+              // TODO(NODE-5192): Remove this cast
+              new ConnectionCheckOutFailedEvent(this, 'connectionError', err as MongoError)
             );
           } else if (connection) {
             this[kCheckedOut].add(connection);

src/cmap/connection_pool_events.ts

@@ -1,5 +1,18 @@
 import type { ObjectId } from '../bson';
-import type { AnyError } from '../error';
+import {
+  CONNECTION_CHECK_OUT_FAILED,
+  CONNECTION_CHECK_OUT_STARTED,
+  CONNECTION_CHECKED_IN,
+  CONNECTION_CHECKED_OUT,
+  CONNECTION_CLOSED,
+  CONNECTION_CREATED,
+  CONNECTION_POOL_CLEARED,
+  CONNECTION_POOL_CLOSED,
+  CONNECTION_POOL_CREATED,
+  CONNECTION_POOL_READY,
+  CONNECTION_READY
+} from '../constants';
+import type { MongoError } from '../error';
 import type { Connection } from './connection';
 import type { ConnectionPool, ConnectionPoolOptions } from './connection_pool';
 
@@ -8,11 +21,24 @@ import type { ConnectionPool, ConnectionPoolOptions } from './connection_pool';
  * @public
  * @category Event
  */
-export class ConnectionPoolMonitoringEvent {
+export abstract class ConnectionPoolMonitoringEvent {
   /** A timestamp when the event was created  */
   time: Date;
   /** The address (host/port pair) of the pool */
   address: string;
+  /** @internal */
+  abstract name:
+    | typeof CONNECTION_CHECK_OUT_FAILED
+    | typeof CONNECTION_CHECK_OUT_STARTED
+    | typeof CONNECTION_CHECKED_IN
+    | typeof CONNECTION_CHECKED_OUT
+    | typeof CONNECTION_CLOSED
+    | typeof CONNECTION_CREATED
+    | typeof CONNECTION_POOL_CLEARED
+    | typeof CONNECTION_POOL_CLOSED
+    | typeof CONNECTION_POOL_CREATED
+    | typeof CONNECTION_POOL_READY
+    | typeof CONNECTION_READY;
 
   /** @internal */
   constructor(pool: ConnectionPool) {
@@ -29,6 +55,8 @@ export class ConnectionPoolMonitoringEvent {
 export class ConnectionPoolCreatedEvent extends ConnectionPoolMonitoringEvent {
   /** The options used to create this connection pool */
   options?: ConnectionPoolOptions;
+  /** @internal */
+  name = CONNECTION_POOL_CREATED;
 
   /** @internal */
   constructor(pool: ConnectionPool) {
@@ -43,6 +71,9 @@ export class ConnectionPoolCreatedEvent extends ConnectionPoolMonitoringEvent {
  * @category Event
  */
 export class ConnectionPoolReadyEvent extends ConnectionPoolMonitoringEvent {
+  /** @internal */
+  name = CONNECTION_POOL_READY;
+
   /** @internal */
   constructor(pool: ConnectionPool) {
     super(pool);
@@ -55,6 +86,9 @@ export class ConnectionPoolReadyEvent extends ConnectionPoolMonitoringEvent {
  * @category Event
  */
 export class ConnectionPoolClosedEvent extends ConnectionPoolMonitoringEvent {
+  /** @internal */
+  name = CONNECTION_POOL_CLOSED;
+
   /** @internal */
   constructor(pool: ConnectionPool) {
     super(pool);
@@ -69,6 +103,8 @@ export class ConnectionPoolClosedEvent extends ConnectionPoolMonitoringEvent {
 export class ConnectionCreatedEvent extends ConnectionPoolMonitoringEvent {
   /** A monotonically increasing, per-pool id for the newly created connection */
   connectionId: number | '<monitor>';
+  /** @internal */
+  name = CONNECTION_CREATED;
 
   /** @internal */
   constructor(pool: ConnectionPool, connection: { id: number | '<monitor>' }) {
@@ -85,6 +121,8 @@ export class ConnectionCreatedEvent extends ConnectionPoolMonitoringEvent {
 export class ConnectionReadyEvent extends ConnectionPoolMonitoringEvent {
   /** The id of the connection */
   connectionId: number | '<monitor>';
+  /** @internal */
+  name = CONNECTION_READY;
 
   /** @internal */
   constructor(pool: ConnectionPool, connection: Connection) {
@@ -104,17 +142,23 @@ export class ConnectionClosedEvent extends ConnectionPoolMonitoringEvent {
   /** The reason the connection was closed */
   reason: string;
   serviceId?: ObjectId;
+  /** @internal */
+  name = CONNECTION_CLOSED;
+  /** @internal */
+  error: MongoError | null;
 
   /** @internal */
   constructor(
     pool: ConnectionPool,
     connection: Pick<Connection, 'id' | 'serviceId'>,
-    reason: string
+    reason: 'idle' | 'stale' | 'poolClosed' | 'error',
+    error?: MongoError
   ) {
     super(pool);
     this.connectionId = connection.id;
-    this.reason = reason || 'unknown';
+    this.reason = reason;
     this.serviceId = connection.serviceId;
+    this.error = error ?? null;
   }
 }
 
@@ -124,6 +168,9 @@ export class ConnectionClosedEvent extends ConnectionPoolMonitoringEvent {
  * @category Event
  */
 export class ConnectionCheckOutStartedEvent extends ConnectionPoolMonitoringEvent {
+  /** @internal */
+  name = CONNECTION_CHECK_OUT_STARTED;
+
   /** @internal */
   constructor(pool: ConnectionPool) {
     super(pool);
@@ -137,12 +184,21 @@ export class ConnectionCheckOutStartedEvent extends ConnectionPoolMonitoringEven
  */
 export class ConnectionCheckOutFailedEvent extends ConnectionPoolMonitoringEvent {
   /** The reason the attempt to check out failed */
-  reason: AnyError | string;
+  reason: string;
+  /** @internal */
+  error?: MongoError;
+  /** @internal */
+  name = CONNECTION_CHECK_OUT_FAILED;
 
   /** @internal */
-  constructor(pool: ConnectionPool, reason: AnyError | string) {
+  constructor(
+    pool: ConnectionPool,
+    reason: 'poolClosed' | 'timeout' | 'connectionError',
+    error?: MongoError
+  ) {
     super(pool);
     this.reason = reason;
+    this.error = error;
   }
 }
 
@@ -154,6 +210,8 @@ export class ConnectionCheckOutFailedEvent extends ConnectionPoolMonitoringEvent
 export class ConnectionCheckedOutEvent extends ConnectionPoolMonitoringEvent {
   /** The id of the connection */
   connectionId: number | '<monitor>';
+  /** @internal */
+  name = CONNECTION_CHECKED_OUT;
 
   /** @internal */
   constructor(pool: ConnectionPool, connection: Connection) {
@@ -170,6 +228,8 @@ export class ConnectionCheckedOutEvent extends ConnectionPoolMonitoringEvent {
 export class ConnectionCheckedInEvent extends ConnectionPoolMonitoringEvent {
   /** The id of the connection */
   connectionId: number | '<monitor>';
+  /** @internal */
+  name = CONNECTION_CHECKED_IN;
 
   /** @internal */
   constructor(pool: ConnectionPool, connection: Connection) {
@@ -188,6 +248,8 @@ export class ConnectionPoolClearedEvent extends ConnectionPoolMonitoringEvent {
   serviceId?: ObjectId;
 
   interruptInUseConnections?: boolean;
+  /** @internal */
+  name = CONNECTION_POOL_CLEARED;
 
   /** @internal */
   constructor(

src/connection_string.ts

@@ -1280,5 +1280,6 @@ export const DEFAULT_OPTIONS = new CaseInsensitiveMap(
  */
 export const FEATURE_FLAGS = new Set([
   Symbol.for('@@mdb.skipPingOnConnect'),
-  Symbol.for('@@mdb.enableMongoLogger')
+  Symbol.for('@@mdb.enableMongoLogger'),
+  Symbol.for('@@mdb.internalLoggerConfig')
 ]);

src/constants.ts

@@ -23,16 +23,27 @@ export const SERVER_DESCRIPTION_CHANGED = 'serverDescriptionChanged' as const;
 export const TOPOLOGY_OPENING = 'topologyOpening' as const;
 export const TOPOLOGY_CLOSED = 'topologyClosed' as const;
 export const TOPOLOGY_DESCRIPTION_CHANGED = 'topologyDescriptionChanged' as const;
+/** @internal */
 export const CONNECTION_POOL_CREATED = 'connectionPoolCreated' as const;
+/** @internal */
 export const CONNECTION_POOL_CLOSED = 'connectionPoolClosed' as const;
+/** @internal */
 export const CONNECTION_POOL_CLEARED = 'connectionPoolCleared' as const;
+/** @internal */
 export const CONNECTION_POOL_READY = 'connectionPoolReady' as const;
+/** @internal */
 export const CONNECTION_CREATED = 'connectionCreated' as const;
+/** @internal */
 export const CONNECTION_READY = 'connectionReady' as const;
+/** @internal */
 export const CONNECTION_CLOSED = 'connectionClosed' as const;
+/** @internal */
 export const CONNECTION_CHECK_OUT_STARTED = 'connectionCheckOutStarted' as const;
+/** @internal */
 export const CONNECTION_CHECK_OUT_FAILED = 'connectionCheckOutFailed' as const;
+/** @internal */
 export const CONNECTION_CHECKED_OUT = 'connectionCheckedOut' as const;
+/** @internal */
 export const CONNECTION_CHECKED_IN = 'connectionCheckedIn' as const;
 export const CLUSTER_TIME_RECEIVED = 'clusterTimeReceived' as const;
 export const COMMAND_STARTED = 'commandStarted' as const;

src/index.ts

@@ -248,7 +248,20 @@ export type { ConnectionPoolMetrics } from './cmap/metrics';
 export type { StreamDescription, StreamDescriptionOptions } from './cmap/stream_description';
 export type { CompressorName } from './cmap/wire_protocol/compression';
 export type { CollectionOptions, CollectionPrivate, ModifyResult } from './collection';
-export type { MONGO_CLIENT_EVENTS } from './constants';
+export type {
+  CONNECTION_CHECK_OUT_FAILED,
+  CONNECTION_CHECK_OUT_STARTED,
+  CONNECTION_CHECKED_IN,
+  CONNECTION_CHECKED_OUT,
+  CONNECTION_CLOSED,
+  CONNECTION_CREATED,
+  CONNECTION_POOL_CLEARED,
+  CONNECTION_POOL_CLOSED,
+  CONNECTION_POOL_CREATED,
+  CONNECTION_POOL_READY,
+  CONNECTION_READY,
+  MONGO_CLIENT_EVENTS
+} from './constants';
 export type {
   AbstractCursorEvents,
   AbstractCursorOptions,
@@ -290,6 +303,11 @@ export type {
   WithSessionCallback
 } from './mongo_client';
 export type {
+  Log,
+  LogConvertible,
+  Loggable,
+  LoggableEvent,
+  MongoDBLogWritable,
   MongoLoggableComponent,
   MongoLogger,
   MongoLoggerEnvOptions,