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

* chore: discourage LLM-generated PRs

* chore: add reading CONTRIBUTING.md to PR checklist

* chore: workflow to close LLM-generated PRs

.github/pull_request_template.md

@@ -26,6 +26,7 @@ The `/api/something` endpoint is now `/api/something-else`
 
 ## Checklist:
 
+- [ ] I have carefully read CONTRIBUTING.md
 - [ ] I have performed a self-review of my own code
 - [ ] I have made corresponding changes to the documentation if applicable
 - [ ] I have no unrelated changes in the PR.

.github/workflows/close-llm-pr.yml

@@ -0,0 +1,38 @@
+name: Close LLM-generated PRs
+
+on:
+  pull_request:
+    types: [labeled]
+
+permissions: {}
+
+jobs:
+  comment_and_close:
+    runs-on: ubuntu-latest
+    if: ${{ github.event.label.name == 'llm-generated' }}
+    permissions:
+      pull-requests: write
+    steps:
+      - name: Comment and close
+        env:
+          GH_TOKEN: ${{ github.token }}
+          NODE_ID: ${{ github.event.pull_request.node_id }}
+        run: |
+          gh api graphql \
+            -f prId="$NODE_ID" \
+            -f body="Thank you for your interest in contributing to Immich! Unfortunately this PR looks like it was generated using an LLM. As noted in our CONTRIBUTING.md, we request that you don't use LLMs to generate PRs as those are not a good use of maintainer time." \
+            -f query='
+              mutation CommentAndClosePR($prId: ID!, $body: String!) {
+                addComment(input: {
+                  subjectId: $prId,
+                  body: $body
+                }) {
+                  __typename
+                }
+
+                closePullRequest(input: {
+                  pullRequestId: $prId
+                }) {
+                  __typename
+                }
+              }'

CONTRIBUTING.md

@@ -17,7 +17,7 @@ If you are looking for something to work on, there are discussions and issues wi
 
 ## Use of generative AI
 
-We generally discourage PRs entirely generated by an LLM. For any part generated by an LLM, please put extra effort into your self-review. By using generative AI without proper self-review, the time you save ends up being more work we need to put in for proper reviews and code cleanup. Please keep that in mind when submitting code by an LLM. Clearly state the use of LLMs/(generative) AI in your pull request as requested by the template.
+We ask you not to open PRs generated with an LLM. We find that code generated like this tends to need a large amount of back-and-forth, which is a very inefficient use of our time. If we want LLM-generated code, it's much faster for us to use an LLM ourselves than to go through an intermediary via a pull request.
 
 ## Feature freezes
 

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
@@ -53,6 +54,7 @@ services:
       POSTGRES_DB: immich
     ports:
       - 5435:5432
+    shm_size: 128mb
     healthcheck:
       test: ['CMD-SHELL', 'pg_isready -U postgres -d immich']
       interval: 1s

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,
 };