diff --git a/CHANGELOG.md b/CHANGELOG.md
index fd8eaf00e8d7..75dd37bc24ab 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -25,6 +25,8 @@
 
 ### Server
 - Enhance: pg_bigmが利用できるよう、ノートの検索をILIKE演算子でなくLIKE演算子でLOWER()をかけたテキストに対して行うように
+- Enhance: チャート更新時にDBに同時接続しないように  
+  (Cherry-picked from https://activitypub.software/TransFem-org/Sharkey/-/merge_requests/830)
 - Fix: ユーザーのプロフィール画面をアドレス入力などで直接表示した際に概要タブの描画に失敗する問題の修正( #15032 )
 - Fix: 起動前の疎通チェックが機能しなくなっていた問題を修正  
   (Cherry-picked from https://activitypub.software/TransFem-org/Sharkey/-/merge_requests/737)
diff --git a/packages/backend/src/core/chart/ChartManagementService.ts b/packages/backend/src/core/chart/ChartManagementService.ts
index 79681370a17d..f04c561063d1 100644
--- a/packages/backend/src/core/chart/ChartManagementService.ts
+++ b/packages/backend/src/core/chart/ChartManagementService.ts
@@ -58,9 +58,9 @@ export class ChartManagementService implements OnApplicationShutdown {
 	@bindThis
 	public async start() {
 		// 20分おきにメモリ情報をDBに書き込み
-		this.saveIntervalId = setInterval(() => {
+		this.saveIntervalId = setInterval(async () => {
 			for (const chart of this.charts) {
-				chart.save();
+				await chart.save();
 			}
 		}, 1000 * 60 * 20);
 	}
@@ -69,9 +69,9 @@ export class ChartManagementService implements OnApplicationShutdown {
 	public async dispose(): Promise<void> {
 		clearInterval(this.saveIntervalId);
 		if (process.env.NODE_ENV !== 'test') {
-			await Promise.all(
-				this.charts.map(chart => chart.save()),
-			);
+			for (const chart of this.charts) {
+				await chart.save();
+			}
 		}
 	}
 
diff --git a/packages/backend/src/queue/processors/CleanChartsProcessorService.ts b/packages/backend/src/queue/processors/CleanChartsProcessorService.ts
index 110468801ce2..8c5faa8d0711 100644
--- a/packages/backend/src/queue/processors/CleanChartsProcessorService.ts
+++ b/packages/backend/src/queue/processors/CleanChartsProcessorService.ts
@@ -48,20 +48,19 @@ export class CleanChartsProcessorService {
 	public async process(): Promise<void> {
 		this.logger.info('Clean charts...');
 
-		await Promise.all([
-			this.federationChart.clean(),
-			this.notesChart.clean(),
-			this.usersChart.clean(),
-			this.activeUsersChart.clean(),
-			this.instanceChart.clean(),
-			this.perUserNotesChart.clean(),
-			this.perUserPvChart.clean(),
-			this.driveChart.clean(),
-			this.perUserReactionsChart.clean(),
-			this.perUserFollowingChart.clean(),
-			this.perUserDriveChart.clean(),
-			this.apRequestChart.clean(),
-		]);
+		// DBへの同時接続を避けるためにPromise.allを使わずひとつずつ実行する
+		await this.federationChart.clean();
+		await this.notesChart.clean();
+		await this.usersChart.clean();
+		await this.activeUsersChart.clean();
+		await this.instanceChart.clean();
+		await this.perUserNotesChart.clean();
+		await this.perUserPvChart.clean();
+		await this.driveChart.clean();
+		await this.perUserReactionsChart.clean();
+		await this.perUserFollowingChart.clean();
+		await this.perUserDriveChart.clean();
+		await this.apRequestChart.clean();
 
 		this.logger.succ('All charts successfully cleaned.');
 	}
diff --git a/packages/backend/src/queue/processors/ResyncChartsProcessorService.ts b/packages/backend/src/queue/processors/ResyncChartsProcessorService.ts
index 570cdf9a7504..0c47fdedb3b0 100644
--- a/packages/backend/src/queue/processors/ResyncChartsProcessorService.ts
+++ b/packages/backend/src/queue/processors/ResyncChartsProcessorService.ts
@@ -29,13 +29,12 @@ export class ResyncChartsProcessorService {
 	public async process(): Promise<void> {
 		this.logger.info('Resync charts...');
 
+		// DBへの同時接続を避けるためにPromise.allを使わずひとつずつ実行する
 		// TODO: ユーザーごとのチャートも更新する
 		// TODO: インスタンスごとのチャートも更新する
-		await Promise.all([
-			this.driveChart.resync(),
-			this.notesChart.resync(),
-			this.usersChart.resync(),
-		]);
+		await this.driveChart.resync();
+		await this.notesChart.resync();
+		await this.usersChart.resync();
 
 		this.logger.succ('All charts successfully resynced.');
 	}
diff --git a/packages/backend/src/queue/processors/TickChartsProcessorService.ts b/packages/backend/src/queue/processors/TickChartsProcessorService.ts
index 93ec34162db4..fc8856a2710e 100644
--- a/packages/backend/src/queue/processors/TickChartsProcessorService.ts
+++ b/packages/backend/src/queue/processors/TickChartsProcessorService.ts
@@ -48,20 +48,19 @@ export class TickChartsProcessorService {
 	public async process(): Promise<void> {
 		this.logger.info('Tick charts...');
 
-		await Promise.all([
-			this.federationChart.tick(false),
-			this.notesChart.tick(false),
-			this.usersChart.tick(false),
-			this.activeUsersChart.tick(false),
-			this.instanceChart.tick(false),
-			this.perUserNotesChart.tick(false),
-			this.perUserPvChart.tick(false),
-			this.driveChart.tick(false),
-			this.perUserReactionsChart.tick(false),
-			this.perUserFollowingChart.tick(false),
-			this.perUserDriveChart.tick(false),
-			this.apRequestChart.tick(false),
-		]);
+		// DBへの同時接続を避けるためにPromise.allを使わずひとつずつ実行する
+		await this.federationChart.tick(false);
+		await this.notesChart.tick(false);
+		await this.usersChart.tick(false);
+		await this.activeUsersChart.tick(false);
+		await this.instanceChart.tick(false);
+		await this.perUserNotesChart.tick(false);
+		await this.perUserPvChart.tick(false);
+		await this.driveChart.tick(false);
+		await this.perUserReactionsChart.tick(false);
+		await this.perUserFollowingChart.tick(false);
+		await this.perUserDriveChart.tick(false);
+		await this.apRequestChart.tick(false);
 
 		this.logger.succ('All charts successfully ticked.');
 	}