feat: socket.io redis->postgres socket.io, add broadcastchannel option

e2e/docker-compose.yml

@@ -10,6 +10,7 @@ services:
   immich-server:
     container_name: immich-e2e-server
     image: immich-server:latest
+    shm_size: 128mb
     build:
       context: ../
       dockerfile: server/Dockerfile

pnpm-lock.yaml

@@ -406,9 +406,12 @@ importers:
       '@react-email/render':
         specifier: ^1.1.2
         version: 1.4.0(react-dom@19.2.4(react@19.2.4))(react@19.2.4)
-      '@socket.io/redis-adapter':
-        specifier: ^8.3.0
-        version: 8.3.0(socket.io-adapter@2.5.6)
+      '@socket.io/postgres-adapter':
+        specifier: ^0.5.0
+        version: 0.5.0(socket.io-adapter@2.5.6)
+      '@types/pg':
+        specifier: ^8.16.0
+        version: 8.16.0
       ajv:
         specifier: ^8.17.1
         version: 8.17.1
@@ -562,6 +565,9 @@ importers:
       socket.io:
         specifier: ^4.8.1
         version: 4.8.3
+      socket.io-adapter:
+        specifier: ^2.5.6
+        version: 2.5.6
       tailwindcss-preset-email:
         specifier: ^1.4.0
         version: 1.4.1(tailwindcss@3.4.19(tsx@4.21.0)(yaml@2.8.2))
@@ -3402,6 +3408,10 @@ packages:
   '@microsoft/tsdoc@0.16.0':
     resolution: {integrity: sha512-xgAyonlVVS+q7Vc7qLW0UrJU7rSFcETRWsqdXZtjzRU8dF+6CkozTK4V4y1LwOX7j8r/vHphjDeMeGI4tNGeGA==}
 
+  '@msgpack/msgpack@2.8.0':
+    resolution: {integrity: sha512-h9u4u/jiIRKbq25PM+zymTyW6bhTzELvOoUd+AvYriWOAKpLGnIamaET3pnHYoI5iYphAHBI4ayx0MehR+VVPQ==}
+    engines: {node: '>= 10'}
+
   '@msgpackr-extract/msgpackr-extract-darwin-arm64@3.0.3':
     resolution: {integrity: sha512-QZHtlVgbAdy2zAqNA9Gu1UpIuI8Xvsd1v8ic6B2pZmeFnFcMWiPLfWXh7TVw4eGEZ/C9TH281KwhVoeQUKbyjw==}
     cpu: [arm64]
@@ -4310,9 +4320,9 @@ packages:
   '@socket.io/component-emitter@3.1.2':
     resolution: {integrity: sha512-9BCxFwvbGg/RsZK9tjXd8s4UcwR0MWeFQ1XEKIQVVvAGJyINdrqKMcTRyLoK8Rse1GjzLV9cwjWV1olXRWEXVA==}
 
-  '@socket.io/redis-adapter@8.3.0':
-    resolution: {integrity: sha512-ly0cra+48hDmChxmIpnESKrc94LjRL80TEmZVscuQ/WWkRP81nNj8W8cCGMqbI4L6NCuAaPRSzZF1a9GlAxxnA==}
-    engines: {node: '>=10.0.0'}
+  '@socket.io/postgres-adapter@0.5.0':
+    resolution: {integrity: sha512-s1vFsatB4lS429ZbeAi8ju+mZMgtgdSmi9UsZsdcEG++vVtX5z10yDEt4TV8saePscvvGjs6uXvJfMCxz8+M2Q==}
+    engines: {node: '>=12.0.0'}
     peerDependencies:
       socket.io-adapter: ^2.5.4
 
@@ -9285,9 +9295,6 @@ packages:
   not@0.1.0:
     resolution: {integrity: sha512-5PDmaAsVfnWUgTUbJ3ERwn7u79Z0dYxN9ErxCpVJJqe2RK0PJ3z+iFUxuqjwtlDDegXvtWoxD/3Fzxox7tFGWA==}
 
-  notepack.io@3.0.1:
-    resolution: {integrity: sha512-TKC/8zH5pXIAMVQio2TvVDTtPRX+DJPHDqjRbxogtFiByHyzKmy96RA0JtCQJ+WouyyL4A10xomQzgbUT+1jCg==}
-
   npm-run-path@4.0.1:
     resolution: {integrity: sha512-S48WzZW777zhNIrn7gxOlISNAqi9ZC/uQFnRdbeIHhZhCA6UqpkOT8T1G7BvfdgP4Er8gF4sUbaS0i7QvIfCWw==}
     engines: {node: '>=8'}
@@ -11619,10 +11626,6 @@ packages:
     engines: {node: '>=0.8.0'}
     hasBin: true
 
-  uid2@1.0.0:
-    resolution: {integrity: sha512-+I6aJUv63YAcY9n4mQreLUt0d4lvwkkopDNmpomkAUz0fAkEMV9pRWxN0EjhW1YfRhcuyHg2v3mwddCDW1+LFQ==}
-    engines: {node: '>= 4.0.0'}
-
   uid@2.0.2:
     resolution: {integrity: sha512-u3xV3X7uzvi5b1MncmZo3i2Aw222Zk1keqLA1YkHldREkAhAqi65wuPfe7lHx8H/Wzy+8CE7S7uS3jekIM5s8g==}
     engines: {node: '>=8'}
@@ -15426,6 +15429,8 @@ snapshots:
 
   '@microsoft/tsdoc@0.16.0': {}
 
+  '@msgpack/msgpack@2.8.0': {}
+
   '@msgpackr-extract/msgpackr-extract-darwin-arm64@3.0.3':
     optional: true
 
@@ -16303,13 +16308,15 @@ snapshots:
 
   '@socket.io/component-emitter@3.1.2': {}
 
-  '@socket.io/redis-adapter@8.3.0(socket.io-adapter@2.5.6)':
+  '@socket.io/postgres-adapter@0.5.0(socket.io-adapter@2.5.6)':
     dependencies:
+      '@msgpack/msgpack': 2.8.0
+      '@types/pg': 8.16.0
       debug: 4.3.7
-      notepack.io: 3.0.1
+      pg: 8.18.0
       socket.io-adapter: 2.5.6
-      uid2: 1.0.0
     transitivePeerDependencies:
+      - pg-native
       - supports-color
 
   '@sphinxxxx/color-conversion@2.2.2': {}
@@ -22280,8 +22287,6 @@ snapshots:
 
   not@0.1.0: {}
 
-  notepack.io@3.0.1: {}
-
   npm-run-path@4.0.1:
     dependencies:
       path-key: 3.1.1
@@ -25030,8 +25035,6 @@ snapshots:
   uglify-js@3.19.3:
     optional: true
 
-  uid2@1.0.0: {}
-
   uid@2.0.2:
     dependencies:
       '@lukeed/csprng': 1.1.0

server/package.json

@@ -56,7 +56,8 @@
     "@opentelemetry/semantic-conventions": "^1.34.0",
     "@react-email/components": "^0.5.0",
     "@react-email/render": "^1.1.2",
-    "@socket.io/redis-adapter": "^8.3.0",
+    "@socket.io/postgres-adapter": "^0.5.0",
+    "@types/pg": "^8.16.0",
     "ajv": "^8.17.1",
     "archiver": "^7.0.0",
     "async-lock": "^1.4.0",
@@ -108,6 +109,7 @@
     "sharp": "^0.34.5",
     "sirv": "^3.0.0",
     "socket.io": "^4.8.1",
+    "socket.io-adapter": "^2.5.6",
     "tailwindcss-preset-email": "^1.4.0",
     "thumbhash": "^0.1.1",
     "transformation-matrix": "^3.1.0",

server/src/app.common.ts

@@ -5,8 +5,9 @@ import cookieParser from 'cookie-parser';
 import { existsSync } from 'node:fs';
 import sirv from 'sirv';
 import { excludePaths, serverVersion } from 'src/constants';
+import { SocketIoAdapter } from 'src/enum';
 import { MaintenanceWorkerService } from 'src/maintenance/maintenance-worker.service';
-import { WebSocketAdapter } from 'src/middleware/websocket.adapter';
+import { createWebSocketAdapter } from 'src/middleware/websocket.adapter';
 import { ConfigRepository } from 'src/repositories/config.repository';
 import { LoggingRepository } from 'src/repositories/logging.repository';
 import { bootstrapTelemetry } from 'src/repositories/telemetry.repository';
@@ -25,6 +26,7 @@ export async function configureExpress(
   {
     permitSwaggerWrite = true,
     ssr,
+    socketIoAdapter,
   }: {
     /**
      * Whether to allow swagger module to write to the specs.json
@@ -36,6 +38,10 @@ export async function configureExpress(
      * Service to use for server-side rendering
      */
     ssr: typeof ApiService | typeof MaintenanceWorkerService;
+    /**
+     * Override the Socket.IO adapter. If not specified, uses the adapter from config.
+     */
+    socketIoAdapter?: SocketIoAdapter;
   },
 ) {
   const configRepository = app.get(ConfigRepository);
@@ -55,7 +61,7 @@ export async function configureExpress(
   }
 
   app.setGlobalPrefix('api', { exclude: excludePaths });
-  app.useWebSocketAdapter(new WebSocketAdapter(app));
+  app.useWebSocketAdapter(await createWebSocketAdapter(app, socketIoAdapter));
 
   useSwagger(app, { write: configRepository.isDev() && permitSwaggerWrite });
 

server/src/controllers/index.ts

@@ -10,6 +10,7 @@ import { DatabaseBackupController } from 'src/controllers/database-backup.contro
 import { DownloadController } from 'src/controllers/download.controller';
 import { DuplicateController } from 'src/controllers/duplicate.controller';
 import { FaceController } from 'src/controllers/face.controller';
+import { InternalController } from 'src/controllers/internal.controller';
 import { JobController } from 'src/controllers/job.controller';
 import { LibraryController } from 'src/controllers/library.controller';
 import { MaintenanceController } from 'src/controllers/maintenance.controller';
@@ -51,6 +52,7 @@ export const controllers = [
   DownloadController,
   DuplicateController,
   FaceController,
+  InternalController,
   JobController,
   LibraryController,
   MaintenanceController,

server/src/controllers/internal.controller.ts

@@ -0,0 +1,22 @@
+import { Body, Controller, NotFoundException, Post, Req } from '@nestjs/common';
+import { ApiExcludeController } from '@nestjs/swagger';
+import { Request } from 'express';
+import { AppRestartEvent, EventRepository } from 'src/repositories/event.repository';
+
+const LOCALHOST_ADDRESSES = new Set(['127.0.0.1', '::1', '::ffff:127.0.0.1']);
+
+@ApiExcludeController()
+@Controller('internal')
+export class InternalController {
+  constructor(private eventRepository: EventRepository) {}
+
+  @Post('restart')
+  async restart(@Req() req: Request, @Body() dto: AppRestartEvent): Promise<void> {
+    const remoteAddress = req.socket.remoteAddress;
+    if (!remoteAddress || !LOCALHOST_ADDRESSES.has(remoteAddress)) {
+      throw new NotFoundException();
+    }
+
+    await this.eventRepository.emit('AppRestart', dto);
+  }
+}

server/src/dtos/env.dto.ts

@@ -1,6 +1,6 @@
 import { Transform, Type } from 'class-transformer';
 import { IsEnum, IsInt, IsString, Matches } from 'class-validator';
-import { DatabaseSslMode, ImmichEnvironment, LogFormat, LogLevel } from 'src/enum';
+import { DatabaseSslMode, ImmichEnvironment, LogFormat, LogLevel, SocketIoAdapter } from 'src/enum';
 import { IsIPRange, Optional, ValidateBoolean } from 'src/validation';
 
 export class EnvDto {
@@ -140,6 +140,11 @@ export class EnvDto {
   @Optional()
   IMMICH_WORKERS_EXCLUDE?: string;
 
+  @IsEnum(SocketIoAdapter)
+  @Optional()
+  @Transform(({ value }) => (value ? String(value).toLowerCase().trim() : value))
+  IMMICH_SOCKETIO_ADAPTER?: SocketIoAdapter;
+
   @IsString()
   @Optional()
   DB_DATABASE_NAME?: string;

server/src/enum.ts

@@ -518,6 +518,11 @@ export enum ImmichTelemetry {
   Job = 'job',
 }
 
+export enum SocketIoAdapter {
+  BroadcastChannel = 'broadcastchannel',
+  Postgres = 'postgres',
+}
+
 export enum ExifOrientation {
   Horizontal = 1,
   MirrorHorizontal = 2,

server/src/main.ts

@@ -1,6 +1,5 @@
 import { Kysely, sql } from 'kysely';
 import { CommandFactory } from 'nest-commander';
-import { ChildProcess, fork } from 'node:child_process';
 import { dirname, join } from 'node:path';
 import { Worker } from 'node:worker_threads';
 import { PostgresError } from 'postgres';
@@ -18,7 +17,7 @@ class Workers {
   /**
    * Currently running workers
    */
-  workers: Partial<Record<ImmichWorker, { kill: (signal: NodeJS.Signals) => Promise<void> | void }>> = {};
+  workers: Partial<Record<ImmichWorker, { kill: () => Promise<void> | void }>> = {};
 
   /**
    * Fail-safe in case anything dies during restart
@@ -101,25 +100,23 @@ class Workers {
     const basePath = dirname(__filename);
     const workerFile = join(basePath, 'workers', `${name}.js`);
 
-    let anyWorker: Worker | ChildProcess;
-    let kill: (signal?: NodeJS.Signals) => Promise<void> | void;
+    const inspectArg = process.execArgv.find((arg) => arg.startsWith('--inspect'));
+    const workerData: { inspectorPort?: number } = {};
 
-    if (name === ImmichWorker.Api) {
-      const worker = fork(workerFile, [], {
-        execArgv: process.execArgv.map((arg) => (arg.startsWith('--inspect') ? '--inspect=0.0.0.0:9231' : arg)),
-      });
-
-      kill = (signal) => void worker.kill(signal);
-      anyWorker = worker;
-    } else {
-      const worker = new Worker(workerFile);
-
-      kill = async () => void (await worker.terminate());
-      anyWorker = worker;
+    if (inspectArg) {
+      const inspectorPorts: Record<ImmichWorker, number> = {
+        [ImmichWorker.Api]: 9230,
+        [ImmichWorker.Microservices]: 9231,
+        [ImmichWorker.Maintenance]: 9232,
+      };
+      workerData.inspectorPort = inspectorPorts[name];
     }
 
-    anyWorker.on('error', (error) => this.onError(name, error));
-    anyWorker.on('exit', (exitCode) => this.onExit(name, exitCode));
+    const worker = new Worker(workerFile, { workerData });
+    const kill = async () => void (await worker.terminate());
+
+    worker.on('error', (error) => this.onError(name, error));
+    worker.on('exit', (exitCode) => this.onExit(name, exitCode));
 
     this.workers[name] = { kill };
   }
@@ -152,8 +149,8 @@ class Workers {
       console.error(`${name} worker exited with code ${exitCode}`);
 
       if (this.workers[ImmichWorker.Api] && name !== ImmichWorker.Api) {
-        console.error('Killing api process');
-        void this.workers[ImmichWorker.Api].kill('SIGTERM');
+        console.error('Terminating api worker');
+        void this.workers[ImmichWorker.Api].kill();
       }
     }
 

server/src/maintenance/maintenance-worker.controller.ts

@@ -4,6 +4,7 @@ import {
   Delete,
   Get,
   Next,
+  NotFoundException,
   Param,
   Post,
   Req,
@@ -25,12 +26,15 @@ import { ImmichCookie } from 'src/enum';
 import { MaintenanceRoute } from 'src/maintenance/maintenance-auth.guard';
 import { MaintenanceWorkerService } from 'src/maintenance/maintenance-worker.service';
 import { GetLoginDetails } from 'src/middleware/auth.guard';
+import { AppRestartEvent } from 'src/repositories/event.repository';
 import { LoggingRepository } from 'src/repositories/logging.repository';
 import { LoginDetails } from 'src/services/auth.service';
 import { sendFile } from 'src/utils/file';
 import { respondWithCookie } from 'src/utils/response';
 import { FilenameParamDto } from 'src/validation';
 
+const LOCALHOST_ADDRESSES = new Set(['127.0.0.1', '::1', '::ffff:127.0.0.1']);
+
 import type { DatabaseBackupController as _DatabaseBackupController } from 'src/controllers/database-backup.controller';
 import type { ServerController as _ServerController } from 'src/controllers/server.controller';
 import { DatabaseBackupDeleteDto, DatabaseBackupListResponseDto } from 'src/dtos/database-backup.dto';
@@ -131,4 +135,14 @@ export class MaintenanceWorkerController {
   setMaintenanceMode(@Body() dto: SetMaintenanceModeDto): void {
     void this.service.setAction(dto);
   }
+
+  @Post('internal/restart')
+  internalRestart(@Req() req: Request, @Body() dto: AppRestartEvent): void {
+    const remoteAddress = req.socket.remoteAddress;
+    if (!remoteAddress || !LOCALHOST_ADDRESSES.has(remoteAddress)) {
+      throw new NotFoundException();
+    }
+
+    this.service.handleInternalRestart(dto);
+  }
 }

server/src/maintenance/maintenance-worker.service.ts

@@ -19,6 +19,7 @@ import { MaintenanceWebsocketRepository } from 'src/maintenance/maintenance-webs
 import { AppRepository } from 'src/repositories/app.repository';
 import { ConfigRepository } from 'src/repositories/config.repository';
 import { DatabaseRepository } from 'src/repositories/database.repository';
+import { AppRestartEvent } from 'src/repositories/event.repository';
 import { LoggingRepository } from 'src/repositories/logging.repository';
 import { ProcessRepository } from 'src/repositories/process.repository';
 import { StorageRepository } from 'src/repositories/storage.repository';
@@ -290,6 +291,9 @@ export class MaintenanceWorkerService {
 
     const lock = await this.databaseRepository.tryLock(DatabaseLock.MaintenanceOperation);
     if (!lock) {
+      // Another maintenance worker has the lock - poll until maintenance mode ends
+      this.logger.log('Another worker has the maintenance lock, polling for maintenance mode changes...');
+      await this.pollForMaintenanceEnd();
       return;
     }
 
@@ -351,4 +355,25 @@ export class MaintenanceWorkerService {
     this.maintenanceWebsocketRepository.serverSend('AppRestart', state);
     this.appRepository.exitApp();
   }
+
+  handleInternalRestart(state: AppRestartEvent): void {
+    this.maintenanceWebsocketRepository.clientBroadcast('AppRestartV1', state);
+    this.maintenanceWebsocketRepository.serverSend('AppRestart', state);
+    this.appRepository.exitApp();
+  }
+
+  private async pollForMaintenanceEnd(): Promise<void> {
+    const pollIntervalMs = 5000;
+
+    while (true) {
+      await new Promise((resolve) => setTimeout(resolve, pollIntervalMs));
+
+      const state = await this.systemMetadataRepository.get(SystemMetadataKey.MaintenanceMode);
+      if (!state?.isMaintenanceMode) {
+        this.logger.log('Maintenance mode ended, restarting...');
+        this.appRepository.exitApp();
+        return;
+      }
+    }
+  }
 }

server/src/middleware/broadcast-channel.adapter.ts

@@ -0,0 +1,80 @@
+import {
+  ClusterAdapterWithHeartbeat,
+  type ClusterAdapterOptions,
+  type ClusterMessage,
+  type ClusterResponse,
+  type ServerId,
+} from 'socket.io-adapter';
+
+const BC_CHANNEL_NAME = 'immich:socketio';
+
+interface BroadcastChannelPayload {
+  type: 'message' | 'response';
+  sourceUid: string;
+  targetUid?: string;
+  data: unknown;
+}
+
+/**
+ * Socket.IO adapter using Node.js BroadcastChannel
+ *
+ * Relays messages between worker_threads within a single OS process.
+ * Zero external dependencies. Does NOT work across containers — use
+ * the Postgres adapter for multi-replica deployments.
+ */
+class BroadcastChannelAdapter extends ClusterAdapterWithHeartbeat {
+  private readonly channel: BroadcastChannel;
+
+  constructor(nsp: any, opts?: Partial<ClusterAdapterOptions>) {
+    super(nsp, opts ?? {});
+
+    this.channel = new BroadcastChannel(BC_CHANNEL_NAME);
+    this.channel.addEventListener('message', (event: MessageEvent<BroadcastChannelPayload>) => {
+      const msg = event.data;
+      if (msg.sourceUid === this.uid) {
+        return;
+      }
+      if (msg.type === 'message') {
+        this.onMessage(msg.data as ClusterMessage);
+      } else if (msg.type === 'response' && msg.targetUid === this.uid) {
+        this.onResponse(msg.data as ClusterResponse);
+      }
+    });
+
+    this.init();
+  }
+
+  override doPublish(message: ClusterMessage): Promise<string> {
+    this.channel.postMessage({
+      type: 'message',
+      sourceUid: this.uid,
+      data: message,
+    });
+    return Promise.resolve('');
+  }
+
+  override doPublishResponse(requesterUid: ServerId, response: ClusterResponse): Promise<void> {
+    this.channel.postMessage({
+      type: 'response',
+      sourceUid: this.uid,
+      targetUid: requesterUid,
+      data: response,
+    });
+    return Promise.resolve();
+  }
+
+  override close(): void {
+    super.close();
+    this.channel.close();
+  }
+}
+
+export function createBroadcastChannelAdapter(opts?: Partial<ClusterAdapterOptions>) {
+  const options: Partial<ClusterAdapterOptions> = {
+    ...opts,
+  };
+
+  return function (nsp: any) {
+    return new BroadcastChannelAdapter(nsp, options);
+  };
+}

server/src/middleware/websocket.adapter.ts

@@ -1,21 +1,103 @@
-import { INestApplicationContext } from '@nestjs/common';
+import { INestApplication, Logger } from '@nestjs/common';
 import { IoAdapter } from '@nestjs/platform-socket.io';
-import { createAdapter } from '@socket.io/redis-adapter';
-import { Redis } from 'ioredis';
-import { ServerOptions } from 'socket.io';
+import { Pool, PoolConfig } from 'pg';
+import type { ServerOptions } from 'socket.io';
+import { SocketIoAdapter } from 'src/enum';
+import { createBroadcastChannelAdapter } from 'src/middleware/broadcast-channel.adapter';
 import { ConfigRepository } from 'src/repositories/config.repository';
+import { asPostgresConnectionConfig } from 'src/utils/database';
 
-export class WebSocketAdapter extends IoAdapter {
-  constructor(private app: INestApplicationContext) {
+export type Ssl = 'require' | 'allow' | 'prefer' | 'verify-full' | boolean | object;
+
+export function asPgPoolSsl(ssl?: Ssl): PoolConfig['ssl'] {
+  if (ssl === undefined || ssl === false || ssl === 'allow') {
+    return false;
+  }
+
+  if (ssl === true || ssl === 'prefer' || ssl === 'require') {
+    return { rejectUnauthorized: false };
+  }
+
+  if (ssl === 'verify-full') {
+    return { rejectUnauthorized: true };
+  }
+
+  return ssl;
+}
+
+class BroadcastChannelSocketAdapter extends IoAdapter {
+  private adapterConstructor: ReturnType<typeof createBroadcastChannelAdapter>;
+
+  constructor(app: INestApplication) {
     super(app);
+    this.adapterConstructor = createBroadcastChannelAdapter();
   }
 
   createIOServer(port: number, options?: ServerOptions): any {
-    const { redis } = this.app.get(ConfigRepository).getEnv();
     const server = super.createIOServer(port, options);
-    const pubClient = new Redis(redis);
-    const subClient = pubClient.duplicate();
-    server.adapter(createAdapter(pubClient, subClient));
+    server.adapter(this.adapterConstructor);
     return server;
   }
 }
+
+class PostgresSocketAdapter extends IoAdapter {
+  private adapterConstructor: any;
+
+  constructor(app: INestApplication, adapterConstructor: any) {
+    super(app);
+    this.adapterConstructor = adapterConstructor;
+  }
+
+  createIOServer(port: number, options?: ServerOptions): any {
+    const server = super.createIOServer(port, options);
+    server.adapter(this.adapterConstructor);
+    return server;
+  }
+}
+
+export async function createWebSocketAdapter(
+  app: INestApplication,
+  adapterOverride?: SocketIoAdapter,
+): Promise<IoAdapter> {
+  const logger = new Logger('WebSocketAdapter');
+  const config = new ConfigRepository();
+  const { database, socketIo } = config.getEnv();
+  const adapter = adapterOverride ?? socketIo.adapter;
+
+  switch (adapter) {
+    case SocketIoAdapter.Postgres: {
+      logger.log('Using Postgres Socket.IO adapter');
+      const { createAdapter } = await import('@socket.io/postgres-adapter');
+      const config = asPostgresConnectionConfig(database.config);
+      const pool = new Pool({
+        host: config.host,
+        port: config.port,
+        user: config.username,
+        password: config.password,
+        database: config.database,
+        ssl: asPgPoolSsl(config.ssl),
+        max: 2,
+      });
+
+      await pool.query(`
+        CREATE TABLE IF NOT EXISTS socket_io_attachments (
+            id          bigserial UNIQUE,
+            created_at  timestamptz DEFAULT NOW(),
+            payload     bytea
+        );
+      `);
+
+      pool.on('error', (error) => {
+        logger.error(' Postgres pool error', error);
+      });
+
+      const adapterConstructor = createAdapter(pool);
+      return new PostgresSocketAdapter(app, adapterConstructor);
+    }
+
+    case SocketIoAdapter.BroadcastChannel: {
+      logger.log('Using BroadcastChannel Socket.IO adapter');
+      return new BroadcastChannelSocketAdapter(app);
+    }
+  }
+}

server/src/repositories/app.repository.ts

@@ -1,7 +1,4 @@
 import { Injectable } from '@nestjs/common';
-import { createAdapter } from '@socket.io/redis-adapter';
-import Redis from 'ioredis';
-import { Server as SocketIO } from 'socket.io';
 import { ExitCode } from 'src/enum';
 import { ConfigRepository } from 'src/repositories/config.repository';
 import { AppRestartEvent } from 'src/repositories/event.repository';
@@ -24,24 +21,17 @@ export class AppRepository {
   }
 
   async sendOneShotAppRestart(state: AppRestartEvent): Promise<void> {
-    const server = new SocketIO();
-    const { redis } = new ConfigRepository().getEnv();
-    const pubClient = new Redis({ ...redis, lazyConnect: true });
-    const subClient = pubClient.duplicate();
+    const { port } = new ConfigRepository().getEnv();
+    const url = `http://127.0.0.1:${port}/api/internal/restart`;
 
-    await Promise.all([pubClient.connect(), subClient.connect()]);
-
-    server.adapter(createAdapter(pubClient, subClient));
-
-    // => corresponds to notification.service.ts#onAppRestart
-    server.emit('AppRestartV1', state, async () => {
-      const responses = await server.serverSideEmitWithAck('AppRestart', state);
-      if (responses.some((response) => response !== 'ok')) {
-        throw new Error("One or more node(s) returned a non-'ok' response to our restart request!");
-      }
-
-      pubClient.disconnect();
-      subClient.disconnect();
+    const response = await fetch(url, {
+      method: 'POST',
+      headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify(state),
     });
+
+    if (!response.ok) {
+      throw new Error(`Failed to trigger app restart: ${response.status} ${response.statusText}`);
+    }
   }
 }

server/src/repositories/config.repository.ts

@@ -20,6 +20,7 @@ import {
   LogFormat,
   LogLevel,
   QueueName,
+  SocketIoAdapter,
 } from 'src/enum';
 import { DatabaseConnectionParams, VectorExtension } from 'src/types';
 import { setDifference } from 'src/utils/set';
@@ -116,6 +117,10 @@ export interface EnvData {
     };
   };
 
+  socketIo: {
+    adapter: SocketIoAdapter;
+  };
+
   noColor: boolean;
   nodeVersion?: string;
 }
@@ -346,6 +351,10 @@ const getEnv = (): EnvData => {
       },
     },
 
+    socketIo: {
+      adapter: dto.IMMICH_SOCKETIO_ADAPTER ?? SocketIoAdapter.Postgres,
+    },
+
     noColor: !!dto.NO_COLOR,
   };
 };

server/src/utils/maintenance.ts

@@ -1,60 +1,11 @@
-import { createAdapter } from '@socket.io/redis-adapter';
-import Redis from 'ioredis';
 import { SignJWT } from 'jose';
 import { randomBytes } from 'node:crypto';
 import { join } from 'node:path';
-import { Server as SocketIO } from 'socket.io';
 import { StorageCore } from 'src/cores/storage.core';
 import { MaintenanceAuthDto, MaintenanceDetectInstallResponseDto } from 'src/dtos/maintenance.dto';
 import { StorageFolder } from 'src/enum';
-import { ConfigRepository } from 'src/repositories/config.repository';
-import { AppRestartEvent } from 'src/repositories/event.repository';
 import { StorageRepository } from 'src/repositories/storage.repository';
 
-export function sendOneShotAppRestart(state: AppRestartEvent): void {
-  const server = new SocketIO();
-  const { redis } = new ConfigRepository().getEnv();
-  const pubClient = new Redis(redis);
-  const subClient = pubClient.duplicate();
-  server.adapter(createAdapter(pubClient, subClient));
-
-  /**
-   * Keep trying until we manage to stop Immich
-   *
-   * Sometimes there appear to be communication
-   * issues between to the other servers.
-   *
-   * This issue only occurs with this method.
-   */
-  async function tryTerminate() {
-    while (true) {
-      try {
-        const responses = await server.serverSideEmitWithAck('AppRestart', state);
-        if (responses.length > 0) {
-          return;
-        }
-      } catch (error) {
-        console.error(error);
-        console.error('Encountered an error while telling Immich to stop.');
-      }
-
-      console.info(
-        "\nIt doesn't appear that Immich stopped, trying again in a moment.\nIf Immich is already not running, you can ignore this error.",
-      );
-
-      await new Promise((r) => setTimeout(r, 1e3));
-    }
-  }
-
-  // => corresponds to notification.service.ts#onAppRestart
-  server.emit('AppRestartV1', state, () => {
-    void tryTerminate().finally(() => {
-      pubClient.disconnect();
-      subClient.disconnect();
-    });
-  });
-}
-
 export async function createMaintenanceLoginUrl(
   baseUrl: string,
   auth: MaintenanceAuthDto,

server/src/workers/api.ts

@@ -1,14 +1,21 @@
 import { NestFactory } from '@nestjs/core';
 import { NestExpressApplication } from '@nestjs/platform-express';
+import inspector from 'node:inspector';
+import { isMainThread, workerData } from 'node:worker_threads';
 import { configureExpress, configureTelemetry } from 'src/app.common';
 import { ApiModule } from 'src/app.module';
 import { AppRepository } from 'src/repositories/app.repository';
 import { ApiService } from 'src/services/api.service';
 import { isStartUpError } from 'src/utils/misc';
 
-async function bootstrap() {
+export async function bootstrap() {
   process.title = 'immich-api';
 
+  const { inspectorPort } = workerData ?? {};
+  if (inspectorPort) {
+    inspector.open(inspectorPort, '0.0.0.0', false);
+  }
+
   configureTelemetry();
 
   const app = await NestFactory.create<NestExpressApplication>(ApiModule, { bufferLogs: true });
@@ -19,10 +26,12 @@ async function bootstrap() {
   });
 }
 
-bootstrap().catch((error) => {
-  if (!isStartUpError(error)) {
-    console.error(error);
-  }
-  // eslint-disable-next-line unicorn/no-process-exit
-  process.exit(1);
-});
+if (!isMainThread || process.send) {
+  bootstrap().catch((error) => {
+    if (!isStartUpError(error)) {
+      console.error(error);
+    }
+
+    process.exit(1);
+  });
+}

server/src/workers/maintenance.ts

@@ -1,13 +1,22 @@
 import { NestFactory } from '@nestjs/core';
 import { NestExpressApplication } from '@nestjs/platform-express';
+import inspector from 'node:inspector';
+import { isMainThread, workerData } from 'node:worker_threads';
 import { configureExpress, configureTelemetry } from 'src/app.common';
 import { MaintenanceModule } from 'src/app.module';
+import { SocketIoAdapter } from 'src/enum';
 import { MaintenanceWorkerService } from 'src/maintenance/maintenance-worker.service';
 import { AppRepository } from 'src/repositories/app.repository';
 import { isStartUpError } from 'src/utils/misc';
 
-async function bootstrap() {
+export async function bootstrap() {
   process.title = 'immich-maintenance';
+
+  const { inspectorPort } = workerData ?? {};
+  if (inspectorPort) {
+    inspector.open(inspectorPort, '0.0.0.0', false);
+  }
+
   configureTelemetry();
 
   const app = await NestFactory.create<NestExpressApplication>(MaintenanceModule, { bufferLogs: true });
@@ -16,13 +25,18 @@ async function bootstrap() {
   void configureExpress(app, {
     permitSwaggerWrite: false,
     ssr: MaintenanceWorkerService,
+    // Use BroadcastChannel instead of Postgres adapter to avoid crash when
+    // pg_terminate_backend() kills all database connections during restore
+    socketIoAdapter: SocketIoAdapter.BroadcastChannel,
   });
 }
 
-bootstrap().catch((error) => {
-  if (!isStartUpError(error)) {
-    console.error(error);
-  }
-  // eslint-disable-next-line unicorn/no-process-exit
-  process.exit(1);
-});
+if (!isMainThread) {
+  bootstrap().catch((error) => {
+    if (!isStartUpError(error)) {
+      console.error(error);
+    }
+
+    process.exit(1);
+  });
+}

server/src/workers/microservices.ts

@@ -1,8 +1,9 @@
 import { NestFactory } from '@nestjs/core';
-import { isMainThread } from 'node:worker_threads';
+import inspector from 'node:inspector';
+import { isMainThread, workerData } from 'node:worker_threads';
 import { MicroservicesModule } from 'src/app.module';
 import { serverVersion } from 'src/constants';
-import { WebSocketAdapter } from 'src/middleware/websocket.adapter';
+import { createWebSocketAdapter } from 'src/middleware/websocket.adapter';
 import { AppRepository } from 'src/repositories/app.repository';
 import { ConfigRepository } from 'src/repositories/config.repository';
 import { LoggingRepository } from 'src/repositories/logging.repository';
@@ -10,6 +11,11 @@ import { bootstrapTelemetry } from 'src/repositories/telemetry.repository';
 import { isStartUpError } from 'src/utils/misc';
 
 export async function bootstrap() {
+  const { inspectorPort } = workerData ?? {};
+  if (inspectorPort) {
+    inspector.open(inspectorPort, '0.0.0.0', false);
+  }
+
   const { telemetry } = new ConfigRepository().getEnv();
   if (telemetry.metrics.size > 0) {
     bootstrapTelemetry(telemetry.microservicesPort);
@@ -24,7 +30,7 @@ export async function bootstrap() {
 
   logger.setContext('Bootstrap');
   app.useLogger(logger);
-  app.useWebSocketAdapter(new WebSocketAdapter(app));
+  app.useWebSocketAdapter(await createWebSocketAdapter(app));
 
   await (host ? app.listen(0, host) : app.listen(0));
 

server/test/medium/specs/middleware/broadcast-channel.adapter.spec.ts

@@ -0,0 +1,276 @@
+import { ClusterMessage, ClusterResponse } from 'socket.io-adapter';
+import { createBroadcastChannelAdapter } from 'src/middleware/broadcast-channel.adapter';
+import { vi } from 'vitest';
+
+const createMockNamespace = () => ({
+  name: '/',
+  sockets: new Map(),
+  adapter: null,
+  server: {
+    encoder: {
+      encode: vi.fn().mockReturnValue([]),
+    },
+    _opts: {},
+    sockets: {
+      sockets: new Map(),
+    },
+  },
+});
+
+describe('BroadcastChannelAdapter', () => {
+  describe('createBroadcastChannelAdapter', () => {
+    it('should return a factory function', () => {
+      const factory = createBroadcastChannelAdapter();
+      expect(typeof factory).toBe('function');
+    });
+
+    it('should create adapter instance when factory is called', () => {
+      const mockNamespace = createMockNamespace();
+      const factory = createBroadcastChannelAdapter();
+      const adapter = factory(mockNamespace);
+
+      expect(adapter).toBeDefined();
+      expect(adapter.doPublish).toBeDefined();
+      expect(adapter.doPublishResponse).toBeDefined();
+
+      adapter.close();
+    });
+  });
+
+  describe('BroadcastChannelAdapter message passing', () => {
+    it('should actually send and receive messages between two adapters', async () => {
+      const factory1 = createBroadcastChannelAdapter();
+      const factory2 = createBroadcastChannelAdapter();
+
+      const namespace1 = createMockNamespace();
+      const namespace2 = createMockNamespace();
+
+      const adapter1 = factory1(namespace1);
+      const adapter2 = factory2(namespace2);
+
+      await new Promise((resolve) => setTimeout(resolve, 100));
+
+      const receivedMessages: ClusterMessage[] = [];
+      const messageReceived = new Promise<void>((resolve) => {
+        const originalOnMessage = adapter2.onMessage.bind(adapter2);
+        adapter2.onMessage = (message: ClusterMessage) => {
+          receivedMessages.push(message);
+          resolve();
+          return originalOnMessage(message);
+        };
+      });
+
+      const testMessage = {
+        type: 2,
+        data: {
+          opts: { rooms: new Set(['room1']) },
+          rooms: ['room1'],
+        },
+        nsp: '/',
+      };
+
+      void adapter1.doPublish(testMessage as any);
+
+      await Promise.race([messageReceived, new Promise((resolve) => setTimeout(resolve, 500))]);
+
+      expect(receivedMessages.length).toBeGreaterThan(0);
+
+      adapter1.close();
+      adapter2.close();
+    });
+
+    it('should send ConfigUpdate-style event and receive it on another adapter', async () => {
+      const factory1 = createBroadcastChannelAdapter();
+      const factory2 = createBroadcastChannelAdapter();
+
+      const namespace1 = createMockNamespace();
+      const namespace2 = createMockNamespace();
+
+      const adapter1 = factory1(namespace1);
+      const adapter2 = factory2(namespace2);
+
+      await new Promise((resolve) => setTimeout(resolve, 100));
+
+      const receivedMessages: ClusterMessage[] = [];
+      const messageReceived = new Promise<void>((resolve) => {
+        const originalOnMessage = adapter2.onMessage.bind(adapter2);
+        adapter2.onMessage = (message: ClusterMessage) => {
+          receivedMessages.push(message);
+          if ((message as any)?.data?.event === 'ConfigUpdate') {
+            resolve();
+          }
+          return originalOnMessage(message);
+        };
+      });
+
+      const configUpdateMessage = {
+        type: 2,
+        data: {
+          event: 'ConfigUpdate',
+          payload: { newConfig: { ffmpeg: { crf: 23 } }, oldConfig: { ffmpeg: { crf: 20 } } },
+          opts: { rooms: new Set() },
+          rooms: [],
+        },
+        nsp: '/',
+      };
+
+      void adapter1.doPublish(configUpdateMessage as any);
+
+      await Promise.race([messageReceived, new Promise((resolve) => setTimeout(resolve, 500))]);
+
+      const configMessages = receivedMessages.filter((m) => (m as any)?.data?.event === 'ConfigUpdate');
+      expect(configMessages.length).toBeGreaterThan(0);
+      expect((configMessages[0] as any).data.payload.newConfig.ffmpeg.crf).toBe(23);
+
+      adapter1.close();
+      adapter2.close();
+    });
+
+    it('should send AppRestart-style event and receive it on another adapter', async () => {
+      const factory1 = createBroadcastChannelAdapter();
+      const factory2 = createBroadcastChannelAdapter();
+
+      const namespace1 = createMockNamespace();
+      const namespace2 = createMockNamespace();
+
+      const adapter1 = factory1(namespace1);
+      const adapter2 = factory2(namespace2);
+
+      await new Promise((resolve) => setTimeout(resolve, 100));
+
+      const receivedMessages: ClusterMessage[] = [];
+      const messageReceived = new Promise<void>((resolve) => {
+        const originalOnMessage = adapter2.onMessage.bind(adapter2);
+        adapter2.onMessage = (message: ClusterMessage) => {
+          receivedMessages.push(message);
+          if ((message as any)?.data?.event === 'AppRestart') {
+            resolve();
+          }
+          return originalOnMessage(message);
+        };
+      });
+
+      const appRestartMessage = {
+        type: 2,
+        data: {
+          event: 'AppRestart',
+          payload: { isMaintenanceMode: true },
+          opts: { rooms: new Set() },
+          rooms: [],
+        },
+        nsp: '/',
+      };
+
+      void adapter1.doPublish(appRestartMessage as any);
+
+      await Promise.race([messageReceived, new Promise((resolve) => setTimeout(resolve, 500))]);
+
+      const restartMessages = receivedMessages.filter((m) => (m as any)?.data?.event === 'AppRestart');
+      expect(restartMessages.length).toBeGreaterThan(0);
+      expect((restartMessages[0] as any).data.payload.isMaintenanceMode).toBe(true);
+
+      adapter1.close();
+      adapter2.close();
+    });
+
+    it('should not receive its own messages (echo prevention)', async () => {
+      const factory = createBroadcastChannelAdapter();
+      const namespace = createMockNamespace();
+      const adapter = factory(namespace);
+
+      await new Promise((resolve) => setTimeout(resolve, 100));
+
+      const receivedOwnMessages: ClusterMessage[] = [];
+      const uniqueMarker = `test-${Date.now()}-${Math.random()}`;
+
+      const originalOnMessage = adapter.onMessage.bind(adapter);
+      adapter.onMessage = (message: ClusterMessage) => {
+        if ((message as any)?.data?.marker === uniqueMarker) {
+          receivedOwnMessages.push(message);
+        }
+        return originalOnMessage(message);
+      };
+
+      const testMessage = {
+        type: 2,
+        data: {
+          marker: uniqueMarker,
+          opts: { rooms: new Set() },
+          rooms: [],
+        },
+        nsp: '/',
+      };
+
+      void adapter.doPublish(testMessage as any);
+
+      await new Promise((resolve) => setTimeout(resolve, 200));
+
+      expect(receivedOwnMessages.length).toBe(0);
+
+      adapter.close();
+    });
+
+    it('should send and receive response messages between adapters', async () => {
+      const factory1 = createBroadcastChannelAdapter();
+      const factory2 = createBroadcastChannelAdapter();
+
+      const namespace1 = createMockNamespace();
+      const namespace2 = createMockNamespace();
+
+      const adapter1 = factory1(namespace1);
+      const adapter2 = factory2(namespace2);
+
+      await new Promise((resolve) => setTimeout(resolve, 100));
+
+      const receivedResponses: ClusterResponse[] = [];
+      const responseReceived = new Promise<void>((resolve) => {
+        const originalOnResponse = adapter1.onResponse.bind(adapter1);
+        adapter1.onResponse = (response: ClusterResponse) => {
+          receivedResponses.push(response);
+          resolve();
+          return originalOnResponse(response);
+        };
+      });
+
+      const responseMessage = {
+        type: 3,
+        data: { result: 'success', count: 42 },
+      };
+
+      void adapter2.doPublishResponse((adapter1 as any).uid, responseMessage as any);
+
+      await Promise.race([responseReceived, new Promise((resolve) => setTimeout(resolve, 500))]);
+
+      expect(receivedResponses.length).toBeGreaterThan(0);
+
+      adapter1.close();
+      adapter2.close();
+    });
+  });
+
+  describe('BroadcastChannelAdapter lifecycle', () => {
+    it('should close cleanly without errors', () => {
+      const factory = createBroadcastChannelAdapter();
+      const namespace = createMockNamespace();
+      const adapter = factory(namespace);
+
+      expect(() => adapter.close()).not.toThrow();
+    });
+
+    it('should handle multiple adapters closing in sequence', () => {
+      const factory1 = createBroadcastChannelAdapter();
+      const factory2 = createBroadcastChannelAdapter();
+      const factory3 = createBroadcastChannelAdapter();
+
+      const adapter1 = factory1(createMockNamespace());
+      const adapter2 = factory2(createMockNamespace());
+      const adapter3 = factory3(createMockNamespace());
+
+      expect(() => {
+        adapter1.close();
+        adapter2.close();
+        adapter3.close();
+      }).not.toThrow();
+    });
+  });
+});

server/test/medium/specs/middleware/websocket-integration.spec.ts

@@ -0,0 +1,159 @@
+import { Server } from 'socket.io';
+import { createBroadcastChannelAdapter } from 'src/middleware/broadcast-channel.adapter';
+import { EventRepository } from 'src/repositories/event.repository';
+import { LoggingRepository } from 'src/repositories/logging.repository';
+import { WebsocketRepository } from 'src/repositories/websocket.repository';
+import { automock } from 'test/utils';
+import { vi } from 'vitest';
+
+describe('WebSocket Integration - serverSend with adapters', () => {
+  describe('BroadcastChannel adapter', () => {
+    it('should broadcast ConfigUpdate event through BroadcastChannel adapter', async () => {
+      const createMockNamespace = () => ({
+        name: '/',
+        sockets: new Map(),
+        adapter: null,
+        server: {
+          encoder: { encode: vi.fn().mockReturnValue([]) },
+          _opts: {},
+          sockets: { sockets: new Map() },
+        },
+      });
+
+      const factory1 = createBroadcastChannelAdapter();
+      const factory2 = createBroadcastChannelAdapter();
+
+      const namespace1 = createMockNamespace();
+      const namespace2 = createMockNamespace();
+
+      const adapter1 = factory1(namespace1);
+      const adapter2 = factory2(namespace2);
+
+      await new Promise((resolve) => setTimeout(resolve, 100));
+
+      const receivedMessages: any[] = [];
+      vi.spyOn(adapter2, 'onMessage').mockImplementation((message: any) => {
+        receivedMessages.push(message);
+      });
+
+      const configUpdatePayload = {
+        type: 5,
+        data: {
+          event: 'ConfigUpdate',
+          args: [{ newConfig: { ffmpeg: { crf: 23 } }, oldConfig: { ffmpeg: { crf: 20 } } }],
+        },
+        nsp: '/',
+      };
+
+      void adapter1.doPublish(configUpdatePayload as any);
+
+      await new Promise((resolve) => setTimeout(resolve, 100));
+
+      const configMessages = receivedMessages.filter((m) => m?.data?.event === 'ConfigUpdate');
+      expect(configMessages.length).toBeGreaterThan(0);
+
+      adapter1.close();
+      adapter2.close();
+    });
+
+    it('should broadcast AppRestart event through BroadcastChannel adapter', async () => {
+      const createMockNamespace = () => ({
+        name: '/',
+        sockets: new Map(),
+        adapter: null,
+        server: {
+          encoder: { encode: vi.fn().mockReturnValue([]) },
+          _opts: {},
+          sockets: { sockets: new Map() },
+        },
+      });
+
+      const factory1 = createBroadcastChannelAdapter();
+      const factory2 = createBroadcastChannelAdapter();
+
+      const namespace1 = createMockNamespace();
+      const namespace2 = createMockNamespace();
+
+      const adapter1 = factory1(namespace1);
+      const adapter2 = factory2(namespace2);
+
+      await new Promise((resolve) => setTimeout(resolve, 100));
+
+      const receivedMessages: any[] = [];
+      vi.spyOn(adapter2, 'onMessage').mockImplementation((message: any) => {
+        receivedMessages.push(message);
+      });
+
+      const appRestartPayload = {
+        type: 5,
+        data: {
+          event: 'AppRestart',
+          args: [{ isMaintenanceMode: true }],
+        },
+        nsp: '/',
+      };
+
+      void adapter1.doPublish(appRestartPayload as any);
+
+      await new Promise((resolve) => setTimeout(resolve, 100));
+
+      const restartMessages = receivedMessages.filter((m) => m?.data?.event === 'AppRestart');
+      expect(restartMessages.length).toBeGreaterThan(0);
+
+      adapter1.close();
+      adapter2.close();
+    });
+  });
+
+  describe('WebsocketRepository with adapter', () => {
+    it('should call serverSideEmit when serverSend is called', () => {
+      const mockServer = {
+        serverSideEmit: vi.fn(),
+        on: vi.fn(),
+      } as unknown as Server;
+
+      const eventRepository = automock(EventRepository, {
+        args: [undefined, undefined, { setContext: () => {} }],
+      });
+      const loggingRepository = automock(LoggingRepository, {
+        args: [undefined, { getEnv: () => ({ noColor: false }) }],
+        strict: false,
+      });
+
+      const websocketRepository = new WebsocketRepository(eventRepository, loggingRepository);
+      (websocketRepository as any).server = mockServer;
+
+      websocketRepository.serverSend('ConfigUpdate', {
+        newConfig: { ffmpeg: { crf: 23 } } as any,
+        oldConfig: { ffmpeg: { crf: 20 } } as any,
+      });
+
+      expect(mockServer.serverSideEmit).toHaveBeenCalledWith('ConfigUpdate', {
+        newConfig: { ffmpeg: { crf: 23 } },
+        oldConfig: { ffmpeg: { crf: 20 } },
+      });
+    });
+
+    it('should call serverSideEmit for AppRestart event', () => {
+      const mockServer = {
+        serverSideEmit: vi.fn(),
+        on: vi.fn(),
+      } as unknown as Server;
+
+      const eventRepository = automock(EventRepository, {
+        args: [undefined, undefined, { setContext: () => {} }],
+      });
+      const loggingRepository = automock(LoggingRepository, {
+        args: [undefined, { getEnv: () => ({ noColor: false }) }],
+        strict: false,
+      });
+
+      const websocketRepository = new WebsocketRepository(eventRepository, loggingRepository);
+      (websocketRepository as any).server = mockServer;
+
+      websocketRepository.serverSend('AppRestart', { isMaintenanceMode: true });
+
+      expect(mockServer.serverSideEmit).toHaveBeenCalledWith('AppRestart', { isMaintenanceMode: true });
+    });
+  });
+});

server/test/medium/specs/middleware/websocket.adapter.spec.ts

@@ -0,0 +1,70 @@
+import { INestApplication } from '@nestjs/common';
+import { IoAdapter } from '@nestjs/platform-socket.io';
+import { SocketIoAdapter } from 'src/enum';
+import { asPgPoolSsl, createWebSocketAdapter } from 'src/middleware/websocket.adapter';
+import { Mocked, vi } from 'vitest';
+
+describe('asPgPoolSsl', () => {
+  it('should return false for undefined ssl', () => {
+    expect(asPgPoolSsl()).toBe(false);
+  });
+
+  it('should return false for ssl = false', () => {
+    expect(asPgPoolSsl(false)).toBe(false);
+  });
+
+  it('should return false for ssl = "allow"', () => {
+    expect(asPgPoolSsl('allow')).toBe(false);
+  });
+
+  it('should return { rejectUnauthorized: false } for ssl = true', () => {
+    expect(asPgPoolSsl(true)).toEqual({ rejectUnauthorized: false });
+  });
+
+  it('should return { rejectUnauthorized: false } for ssl = "prefer"', () => {
+    expect(asPgPoolSsl('prefer')).toEqual({ rejectUnauthorized: false });
+  });
+
+  it('should return { rejectUnauthorized: false } for ssl = "require"', () => {
+    expect(asPgPoolSsl('require')).toEqual({ rejectUnauthorized: false });
+  });
+
+  it('should return { rejectUnauthorized: true } for ssl = "verify-full"', () => {
+    expect(asPgPoolSsl('verify-full')).toEqual({ rejectUnauthorized: true });
+  });
+
+  it('should pass through object ssl config unchanged', () => {
+    const sslConfig = { ca: 'certificate', rejectUnauthorized: true };
+    expect(asPgPoolSsl(sslConfig)).toBe(sslConfig);
+  });
+});
+
+describe('createWebSocketAdapter', () => {
+  let mockApp: Mocked<INestApplication>;
+
+  beforeEach(() => {
+    vi.clearAllMocks();
+
+    mockApp = {
+      getHttpServer: vi.fn().mockReturnValue({}),
+    } as unknown as Mocked<INestApplication>;
+  });
+
+  describe('BroadcastChannel adapter', () => {
+    it('should create BroadcastChannel adapter when configured', async () => {
+      const adapter = await createWebSocketAdapter(mockApp, SocketIoAdapter.BroadcastChannel);
+
+      expect(adapter).toBeDefined();
+      expect(adapter).toBeInstanceOf(IoAdapter);
+    });
+  });
+
+  describe('Postgres adapter', () => {
+    it('should create Postgres adapter when configured', async () => {
+      const adapter = await createWebSocketAdapter(mockApp, SocketIoAdapter.Postgres);
+
+      expect(adapter).toBeDefined();
+      expect(adapter).toBeInstanceOf(IoAdapter);
+    });
+  });
+});

server/test/repositories/config.repository.mock.ts

@@ -1,4 +1,4 @@
-import { DatabaseExtension, ImmichEnvironment, ImmichWorker, LogFormat } from 'src/enum';
+import { DatabaseExtension, ImmichEnvironment, ImmichWorker, LogFormat, SocketIoAdapter } from 'src/enum';
 import { ConfigRepository, EnvData } from 'src/repositories/config.repository';
 import { RepositoryInterface } from 'src/types';
 import { Mocked, vitest } from 'vitest';
@@ -99,6 +99,10 @@ const envData: EnvData = {
     },
   },
 
+  socketIo: {
+    adapter: SocketIoAdapter.Postgres,
+  },
+
   noColor: false,
 };