From 12f12da28899c730fa59e23f07cdbc8fc048d904 Mon Sep 17 00:00:00 2001
From: Daria <daria.staferova@n8n.io>
Date: Thu, 11 Sep 2025 11:14:02 +0300
Subject: [PATCH] feat(core): Add mysql pool size and increase it for CI
 (no-changelog) (#19347)

---
 .github/workflows/ci-postgres-mysql.yml                       | 2 ++
 packages/@n8n/config/src/configs/database.config.ts           | 4 ++++
 packages/@n8n/config/test/config.test.ts                      | 1 +
 .../db/src/connection/__tests__/db-connection-options.test.ts | 3 +++
 packages/@n8n/db/src/connection/db-connection-options.ts      | 2 ++
 5 files changed, 12 insertions(+)

diff --git a/.github/workflows/ci-postgres-mysql.yml b/.github/workflows/ci-postgres-mysql.yml
index 96dde604db..0d5d3b536a 100644
--- a/.github/workflows/ci-postgres-mysql.yml
+++ b/.github/workflows/ci-postgres-mysql.yml
@@ -62,6 +62,7 @@ jobs:
     timeout-minutes: 20
     env:
       DB_MYSQLDB_PASSWORD: password
+      DB_MYSQLDB_POOL_SIZE: 20
     steps:
       - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
 
@@ -86,6 +87,7 @@ jobs:
     timeout-minutes: 20
     env:
       DB_MYSQLDB_PASSWORD: password
+      DB_MYSQLDB_POOL_SIZE: 20
     steps:
       - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
 
diff --git a/packages/@n8n/config/src/configs/database.config.ts b/packages/@n8n/config/src/configs/database.config.ts
index 07ce78fb81..ba08b609c1 100644
--- a/packages/@n8n/config/src/configs/database.config.ts
+++ b/packages/@n8n/config/src/configs/database.config.ts
@@ -113,6 +113,10 @@ class MysqlConfig {
 	/** MySQL database user */
 	@Env('DB_MYSQLDB_USER')
 	user: string = 'root';
+
+	/** MySQL connection pool size */
+	@Env('DB_MYSQLDB_POOL_SIZE')
+	poolSize: number = 10;
 }
 
 @Config
diff --git a/packages/@n8n/config/test/config.test.ts b/packages/@n8n/config/test/config.test.ts
index c3eaf26ae4..7b43c01d16 100644
--- a/packages/@n8n/config/test/config.test.ts
+++ b/packages/@n8n/config/test/config.test.ts
@@ -69,6 +69,7 @@ describe('GlobalConfig', () => {
 				password: '',
 				port: 3306,
 				user: 'root',
+				poolSize: 10,
 			},
 			postgresdb: {
 				database: 'n8n',
diff --git a/packages/@n8n/db/src/connection/__tests__/db-connection-options.test.ts b/packages/@n8n/db/src/connection/__tests__/db-connection-options.test.ts
index f0d65ee74b..5e3f130050 100644
--- a/packages/@n8n/db/src/connection/__tests__/db-connection-options.test.ts
+++ b/packages/@n8n/db/src/connection/__tests__/db-connection-options.test.ts
@@ -157,6 +157,7 @@ describe('DbConnectionOptions', () => {
 					port: 3306,
 					user: 'root',
 					password: 'password',
+					poolSize: 10,
 				};
 			});
 
@@ -175,6 +176,7 @@ describe('DbConnectionOptions', () => {
 					password: 'password',
 					migrations: mysqlMigrations,
 					timezone: 'Z',
+					poolSize: 10,
 				});
 			});
 
@@ -193,6 +195,7 @@ describe('DbConnectionOptions', () => {
 					password: 'password',
 					migrations: mysqlMigrations,
 					timezone: 'Z',
+					poolSize: 10,
 				});
 			});
 		});
diff --git a/packages/@n8n/db/src/connection/db-connection-options.ts b/packages/@n8n/db/src/connection/db-connection-options.ts
index acd9154b73..6934904df7 100644
--- a/packages/@n8n/db/src/connection/db-connection-options.ts
+++ b/packages/@n8n/db/src/connection/db-connection-options.ts
@@ -135,10 +135,12 @@ export class DbConnectionOptions {
 	}
 
 	private getMysqlConnectionOptions(dbType: 'mariadb' | 'mysqldb'): MysqlConnectionOptions {
+		const { mysqldb: mysqlConfig } = this.config;
 		return {
 			type: dbType === 'mysqldb' ? 'mysql' : 'mariadb',
 			...this.getCommonOptions(),
 			...this.getOverrides('mysqldb'),
+			poolSize: mysqlConfig.poolSize,
 			migrations: mysqlMigrations,
 			timezone: 'Z', // set UTC as default
 		};