diff --git a/.config/example.yml b/.config/example.yml
index 10239f1a7..24985fd28 100644
--- a/.config/example.yml
+++ b/.config/example.yml
@@ -65,10 +65,10 @@ db:
 #   ┌─────────────────────┐
 #───┘ Redis configuration └─────────────────────────────────────
 
-#redis:
-#  host: localhost
-#  port: 6379
-#  pass: example-pass
+redis:
+  host: localhost
+  port: 6379
+  #pass: example-pass
 
 #   ┌─────────────────────────────┐
 #───┘ Elasticsearch configuration └─────────────────────────────
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 314977703..a17e89ff7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,7 +7,8 @@ If you encounter any problems with updating, please try the following:
 
 11.0.0
 ----------
-* データベースがMongoDBからPostgreSQLに変更されました
+* **データベースがMongoDBからPostgreSQLに変更されました**
+* **Redisが必須に**
 * アカウントを完全に削除できるように
 * ミュート/ブロック時にそのユーザーの投稿のウォッチをすべて解除するように
 * フォロー申請数が実際より1すくなくなる問題を修正
diff --git a/docs/setup.en.md b/docs/setup.en.md
index 2e1706de3..45e3e2c68 100644
--- a/docs/setup.en.md
+++ b/docs/setup.en.md
@@ -24,18 +24,13 @@ Please install and setup these softwares:
 #### Dependencies :package:
 * **[Node.js](https://nodejs.org/en/)** >= 11.7.0
 * **[PostgreSQL](https://www.postgresql.org/)** >= 10
+* **[Redis](https://redis.io/)**
 
 ##### Optional
-* [Redis](https://redis.io/)
-  * Redis is optional, but we strongly recommended to install it
 * [Elasticsearch](https://www.elastic.co/) - required to enable the search feature
 * [FFmpeg](https://www.ffmpeg.org/)
 
-*3.* Setup PostgreSQL
-----------------------------------------------------------------
-:)
-
-*4.* Install Misskey
+*3.* Install Misskey
 ----------------------------------------------------------------
 1. `su - misskey` Connect to misskey user.
 2. `git clone -b master git://github.com/syuilo/misskey.git` Clone the misskey repo from master branch.
@@ -43,12 +38,12 @@ Please install and setup these softwares:
 4. `git checkout $(git tag -l | grep -Ev -- '-(rc|alpha)\.[0-9]+$' | sort -V | tail -n 1)` Checkout to the [latest release](https://github.com/syuilo/misskey/releases/latest)
 5. `npm install` Install misskey dependencies.
 
-*5.* Configure Misskey
+*4.* Configure Misskey
 ----------------------------------------------------------------
 1. `cp .config/example.yml .config/default.yml` Copy the `.config/example.yml` and rename it to `default.yml`.
 2. Edit `default.yml`
 
-*6.* Build Misskey
+*5.* Build Misskey
 ----------------------------------------------------------------
 
 Build misskey with the following:
@@ -64,13 +59,13 @@ If you're still encountering errors about some modules, use node-gyp:
 3. `node-gyp build`
 4. `NODE_ENV=production npm run build`
 
-*7.* Init DB
+*6.* Init DB
 ----------------------------------------------------------------
 ``` shell
 npm run init
 ```
 
-*8.* That is it.
+*7.* That is it.
 ----------------------------------------------------------------
 Well done! Now, you have an environment that run to Misskey.
 
diff --git a/docs/setup.fr.md b/docs/setup.fr.md
index 2f8694b9d..e6d36aeff 100644
--- a/docs/setup.fr.md
+++ b/docs/setup.fr.md
@@ -24,18 +24,13 @@ Installez les paquets suivants :
 #### Dépendences :package:
 * **[Node.js](https://nodejs.org/en/)** >= 11.7.0
 * **[PostgreSQL](https://www.postgresql.org/)** >= 10
+* **[Redis](https://redis.io/)**
 
 ##### Optionnels
-* [Redis](https://redis.io/)
-  * Redis est optionnel mais nous vous recommandons vivement de l'installer
 * [Elasticsearch](https://www.elastic.co/) - requis pour pouvoir activer la fonctionnalité de recherche
 * [FFmpeg](https://www.ffmpeg.org/)
 
-*3.* Paramètrage de PostgreSQL
-----------------------------------------------------------------
-:)
-
-*4.* Installation de Misskey
+*3.* Installation de Misskey
 ----------------------------------------------------------------
 1. `su - misskey` Basculez vers l'utilisateur misskey.
 2. `git clone -b master git://github.com/syuilo/misskey.git` Clonez la branche master du dépôt misskey.
@@ -43,12 +38,12 @@ Installez les paquets suivants :
 4. `git checkout $(git tag -l | grep -Ev -- '-(rc|alpha)\.[0-9]+$' | sort -V | tail -n 1)` Checkout sur le tag de la [version la plus récente](https://github.com/syuilo/misskey/releases/latest)
 5. `npm install` Installez les dépendances de misskey.
 
-*5.* Création du fichier de configuration
+*4.* Création du fichier de configuration
 ----------------------------------------------------------------
 1. `cp .config/example.yml .config/default.yml` Copiez le fichier `.config/example.yml` et renommez-le`default.yml`.
 2. Editez le fichier `default.yml`
 
-*6.* Construction de Misskey
+*5.* Construction de Misskey
 ----------------------------------------------------------------
 
 Construisez Misskey comme ceci :
@@ -64,7 +59,7 @@ Si vous rencontrez des erreurs concernant certains modules, utilisez node-gyp:
 3. `node-gyp build`
 4. `NODE_ENV=production npm run build`
 
-*7.* C'est tout.
+*6.* C'est tout.
 ----------------------------------------------------------------
 Excellent ! Maintenant, vous avez un environnement prêt pour lancer Misskey
 
diff --git a/docs/setup.ja.md b/docs/setup.ja.md
index f636a7418..1b1730b69 100644
--- a/docs/setup.ja.md
+++ b/docs/setup.ja.md
@@ -24,25 +24,14 @@ adduser --disabled-password --disabled-login misskey
 #### 依存関係 :package:
 * **[Node.js](https://nodejs.org/en/)** (11.7.0以上)
 * **[PostgreSQL](https://www.postgresql.org/)** (10以上)
+* **[Redis](https://redis.io/)**
 
 ##### オプション
-* [Redis](https://redis.io/)
-	* Redisはオプションですが、インストールすることを強く推奨します。
-	* インストールしなくていいのは、あなたのインスタンスが自分専用のときだけとお考えください。
-	* 具体的には、Redisをインストールしないと、次の事が出来なくなります:
-		* Misskeyプロセスを複数起動しての負荷分散
-		* レートリミット
-		* ジョブキュー
-		* Twitter連携
 * [Elasticsearch](https://www.elastic.co/)
 	* 検索機能を有効にするためにはインストールが必要です。
 * [FFmpeg](https://www.ffmpeg.org/)
 
-*3.* PostgreSQLの設定
-----------------------------------------------------------------
-:)
-
-*4.* Misskeyのインストール
+*3.* Misskeyのインストール
 ----------------------------------------------------------------
 1. `su - misskey` misskeyユーザーを使用
 2. `git clone -b master git://github.com/syuilo/misskey.git` masterブランチからMisskeyレポジトリをクローン
@@ -50,12 +39,12 @@ adduser --disabled-password --disabled-login misskey
 4. `git checkout $(git tag -l | grep -Ev -- '-(rc|alpha)\.[0-9]+$' | sort -V | tail -n 1)` [最新のリリース](https://github.com/syuilo/misskey/releases/latest)を確認
 5. `npm install` Misskeyの依存パッケージをインストール
 
-*5.* 設定ファイルを作成する
+*4.* 設定ファイルを作成する
 ----------------------------------------------------------------
 1. `cp .config/example.yml .config/default.yml` `.config/example.yml`をコピーし名前を`default.yml`にする。
 2. `default.yml` を編集する。
 
-*6.* Misskeyのビルド
+*5.* Misskeyのビルド
 ----------------------------------------------------------------
 
 次のコマンドでMisskeyをビルドしてください:
@@ -70,13 +59,13 @@ Debianをお使いであれば、`build-essential`パッケージをインスト
 3. `node-gyp build`
 4. `NODE_ENV=production npm run build`
 
-*7.* データベースを初期化
+*6.* データベースを初期化
 ----------------------------------------------------------------
 ``` shell
 npm run init
 ```
 
-*8.* 以上です！
+*7.* 以上です！
 ----------------------------------------------------------------
 お疲れ様でした。これでMisskeyを動かす準備は整いました。
 
diff --git a/src/db/redis.ts b/src/db/redis.ts
index cebf2a10a..6518cb005 100644
--- a/src/db/redis.ts
+++ b/src/db/redis.ts
@@ -1,7 +1,7 @@
 import * as redis from 'redis';
 import config from '../config';
 
-export default config.redis ? redis.createClient(
+export default redis.createClient(
 	config.redis.port,
 	config.redis.host,
 	{
@@ -9,4 +9,4 @@ export default config.redis ? redis.createClient(
 		prefix: config.redis.prefix,
 		db: config.redis.db || 0
 	}
-) : null;
+);
diff --git a/src/server/api/limiter.ts b/src/server/api/limiter.ts
index 8a6c94458..48d12d3cc 100644
--- a/src/server/api/limiter.ts
+++ b/src/server/api/limiter.ts
@@ -8,12 +8,6 @@ import Logger from '../../services/logger';
 const logger = new Logger('limiter');
 
 export default (endpoint: IEndpoint, user: User) => new Promise((ok, reject) => {
-	// Redisがインストールされてない場合は常に許可
-	if (limiterDB == null) {
-		ok();
-		return;
-	}
-
 	const limitation = endpoint.meta.limit!;
 
 	const key = limitation.hasOwnProperty('key')
diff --git a/src/server/api/service/discord.ts b/src/server/api/service/discord.ts
index b2561dee6..d8a979b5b 100644
--- a/src/server/api/service/discord.ts
+++ b/src/server/api/service/discord.ts
@@ -83,8 +83,6 @@ async function getOAuth2() {
 }
 
 router.get('/connect/discord', async ctx => {
-	if (redis == null) return;
-
 	if (!compareOrigin(ctx)) {
 		ctx.throw(400, 'invalid origin');
 		return;
@@ -110,8 +108,6 @@ router.get('/connect/discord', async ctx => {
 });
 
 router.get('/signin/discord', async ctx => {
-	if (redis == null) return;
-
 	const sessid = uuid();
 
 	const params = {
@@ -138,8 +134,6 @@ router.get('/signin/discord', async ctx => {
 });
 
 router.get('/dc/cb', async ctx => {
-	if (redis == null) return;
-
 	const userToken = getUserToken(ctx);
 
 	const oauth2 = await getOAuth2();
@@ -160,7 +154,7 @@ router.get('/dc/cb', async ctx => {
 		}
 
 		const { redirect_uri, state } = await new Promise<any>((res, rej) => {
-			redis!.get(sessid, async (_, state) => {
+			redis.get(sessid, async (_, state) => {
 				res(JSON.parse(state));
 			});
 		});
@@ -241,7 +235,7 @@ router.get('/dc/cb', async ctx => {
 		}
 
 		const { redirect_uri, state } = await new Promise<any>((res, rej) => {
-			redis!.get(userToken, async (_, state) => {
+			redis.get(userToken, async (_, state) => {
 				res(JSON.parse(state));
 			});
 		});
diff --git a/src/server/api/service/github.ts b/src/server/api/service/github.ts
index 4878d8c52..a4d274cc6 100644
--- a/src/server/api/service/github.ts
+++ b/src/server/api/service/github.ts
@@ -80,8 +80,6 @@ async function getOath2() {
 }
 
 router.get('/connect/github', async ctx => {
-	if (redis == null) return;
-
 	if (!compareOrigin(ctx)) {
 		ctx.throw(400, 'invalid origin');
 		return;
@@ -106,8 +104,6 @@ router.get('/connect/github', async ctx => {
 });
 
 router.get('/signin/github', async ctx => {
-	if (redis == null) return;
-
 	const sessid = uuid();
 
 	const params = {
@@ -133,8 +129,6 @@ router.get('/signin/github', async ctx => {
 });
 
 router.get('/gh/cb', async ctx => {
-	if (redis == null) return;
-
 	const userToken = getUserToken(ctx);
 
 	const oauth2 = await getOath2();
@@ -155,7 +149,7 @@ router.get('/gh/cb', async ctx => {
 		}
 
 		const { redirect_uri, state } = await new Promise<any>((res, rej) => {
-			redis!.get(sessid, async (_, state) => {
+			redis.get(sessid, async (_, state) => {
 				res(JSON.parse(state));
 			});
 		});
@@ -222,7 +216,7 @@ router.get('/gh/cb', async ctx => {
 		}
 
 		const { redirect_uri, state } = await new Promise<any>((res, rej) => {
-			redis!.get(userToken, async (_, state) => {
+			redis.get(userToken, async (_, state) => {
 				res(JSON.parse(state));
 			});
 		});
diff --git a/src/server/api/service/twitter.ts b/src/server/api/service/twitter.ts
index b35ee8c47..39fdfd865 100644
--- a/src/server/api/service/twitter.ts
+++ b/src/server/api/service/twitter.ts
@@ -79,8 +79,6 @@ async function getTwAuth() {
 }
 
 router.get('/connect/twitter', async ctx => {
-	if (redis == null) return;
-
 	if (!compareOrigin(ctx)) {
 		ctx.throw(400, 'invalid origin');
 		return;
@@ -99,8 +97,6 @@ router.get('/connect/twitter', async ctx => {
 });
 
 router.get('/signin/twitter', async ctx => {
-	if (redis == null) return;
-
 	const twAuth = await getTwAuth();
 	const twCtx = await twAuth!.begin();
 
@@ -122,8 +118,6 @@ router.get('/signin/twitter', async ctx => {
 });
 
 router.get('/tw/cb', async ctx => {
-	if (redis == null) return;
-
 	const userToken = getUserToken(ctx);
 
 	const twAuth = await getTwAuth();
@@ -137,7 +131,7 @@ router.get('/tw/cb', async ctx => {
 		}
 
 		const get = new Promise<any>((res, rej) => {
-			redis!.get(sessid, async (_, twCtx) => {
+			redis.get(sessid, async (_, twCtx) => {
 				res(twCtx);
 			});
 		});
@@ -170,7 +164,7 @@ router.get('/tw/cb', async ctx => {
 		}
 
 		const get = new Promise<any>((res, rej) => {
-			redis!.get(userToken, async (_, twCtx) => {
+			redis.get(userToken, async (_, twCtx) => {
 				res(twCtx);
 			});
 		});
diff --git a/src/server/api/streaming.ts b/src/server/api/streaming.ts
index ab66f2b6d..902c62ef9 100644
--- a/src/server/api/streaming.ts
+++ b/src/server/api/streaming.ts
@@ -1,7 +1,6 @@
 import * as http from 'http';
 import * as websocket from 'websocket';
 import * as redis from 'redis';
-import Xev from 'xev';
 
 import MainStreamConnection from './stream';
 import { ParsedUrlQuery } from 'querystring';
@@ -23,28 +22,24 @@ module.exports = (server: http.Server) => {
 
 		let ev: EventEmitter;
 
-		if (config.redis) {
-			// Connect to Redis
-			const subscriber = redis.createClient(
-				config.redis.port, config.redis.host);
+		// Connect to Redis
+		const subscriber = redis.createClient(
+			config.redis.port, config.redis.host);
 
-			subscriber.subscribe('misskey');
+		subscriber.subscribe('misskey');
 
-			ev = new EventEmitter();
+		ev = new EventEmitter();
 
-			subscriber.on('message', async (_, data) => {
-				const obj = JSON.parse(data);
+		subscriber.on('message', async (_, data) => {
+			const obj = JSON.parse(data);
 
-				ev.emit(obj.channel, obj.message);
-			});
+			ev.emit(obj.channel, obj.message);
+		});
 
-			connection.once('close', () => {
-				subscriber.unsubscribe();
-				subscriber.quit();
-			});
-		} else {
-			ev = new Xev();
-		}
+		connection.once('close', () => {
+			subscriber.unsubscribe();
+			subscriber.quit();
+		});
 
 		const main = new MainStreamConnection(connection, ev, user, app);
 
diff --git a/src/services/stream.ts b/src/services/stream.ts
index c52af48b5..28cb2057e 100644
--- a/src/services/stream.ts
+++ b/src/services/stream.ts
@@ -1,33 +1,19 @@
 import redis from '../db/redis';
-import Xev from 'xev';
 import { User } from '../models/entities/user';
 import { Note } from '../models/entities/note';
 import { UserList } from '../models/entities/user-list';
 import { ReversiGame } from '../models/entities/games/reversi/game';
 
 class Publisher {
-	private ev: Xev | null = null;
-
-	constructor() {
-		// Redisがインストールされてないときはプロセス間通信を使う
-		if (redis == null) {
-			this.ev = new Xev();
-		}
-	}
-
 	private publish = (channel: string, type: string | null, value?: any): void => {
 		const message = type == null ? value : value == null ?
 			{ type: type, body: null } :
 			{ type: type, body: value };
 
-		if (this.ev) {
-			this.ev.emit(channel, message);
-		} else {
-			redis!.publish('misskey', JSON.stringify({
-				channel: channel,
-				message: message
-			}));
-		}
+		redis.publish('misskey', JSON.stringify({
+			channel: channel,
+			message: message
+		}));
 	}
 
 	public publishMainStream = (userId: User['id'], type: string, value?: any): void => {