Add config to override default database ping interval and default idle connection timeout of postgres database (to release a connection from the pool)

Author: guillaumejacquart

packages/@n8n/config/src/configs/database.config.ts

@@ -84,6 +84,10 @@ class PostgresConfig {
 	@Env('DB_POSTGRESDB_CONNECTION_TIMEOUT')
 	connectionTimeoutMs: number = 20_000;
 
+	/** Postgres idle connection timeout (ms) */
+	@Env('DB_POSTGRESDB_IDLE_CONNECTION_TIMEOUT')
+	idleTimeoutMs: number = 30_000;
+
 	@Nested
 	ssl: PostgresSSLConfig;
 }
@@ -158,6 +162,12 @@ export class DatabaseConfig {
 	@Env('DB_TABLE_PREFIX')
 	tablePrefix: string = '';
 
+	/**
+	 * The interval in seconds to ping the database to check if the connection is still alive.
+	 */
+	@Env('DB_PING_INTERVAL_SECONDS')
+	pingIntervalSeconds: number = 2;
+
 	@Nested
 	logging: LoggingConfig;
 

packages/cli/src/databases/__tests__/db-connection-options.test.ts

@@ -102,6 +102,7 @@ describe('DbConnectionOptions', () => {
 						key: '',
 						rejectUnauthorized: true,
 					},
+					idleTimeoutMs: 30000,
 				};
 			});
 
@@ -121,6 +122,9 @@ describe('DbConnectionOptions', () => {
 					migrations: postgresMigrations,
 					connectTimeoutMS: 20000,
 					ssl: false,
+					extra: {
+						idleTimeoutMillis: 30000,
+					},
 				});
 			});
 

packages/cli/src/databases/__tests__/db-connection.test.ts

@@ -1,3 +1,4 @@
+import type { DatabaseConfig } from '@n8n/config';
 import type { Migration } from '@n8n/db';
 import * as migrationHelper from '@n8n/db';
 import { DataSource, type DataSourceOptions } from '@n8n/typeorm';
@@ -17,6 +18,7 @@ describe('DbConnection', () => {
 	let dbConnection: DbConnection;
 	const migrations = [{ name: 'TestMigration1' }, { name: 'TestMigration2' }] as Migration[];
 	const errorReporter = mock<ErrorReporter>();
+	const databaseConfig = mock<DatabaseConfig>();
 	const dataSource = mockDeep<DataSource>({ options: { migrations } });
 	const connectionOptions = mockDeep<DbConnectionOptions>();
 	const postgresOptions: DataSourceOptions = {
@@ -35,7 +37,7 @@ describe('DbConnection', () => {
 		connectionOptions.getOptions.mockReturnValue(postgresOptions);
 		(DataSource as jest.Mock) = jest.fn().mockImplementation(() => dataSource);
 
-		dbConnection = new DbConnection(errorReporter, connectionOptions);
+		dbConnection = new DbConnection(errorReporter, connectionOptions, databaseConfig);
 	});
 
 	describe('init', () => {
@@ -174,5 +176,29 @@ describe('DbConnection', () => {
 
 			expect(dataSource.query).not.toHaveBeenCalled();
 		});
+
+		it('should execute ping on schedule', async () => {
+			jest.useFakeTimers();
+			try {
+				// ARRANGE
+				dbConnection = new DbConnection(
+					errorReporter,
+					connectionOptions,
+					mock<DatabaseConfig>({
+						pingIntervalSeconds: 1,
+					}),
+				);
+
+				const pingSpy = jest.spyOn(dbConnection as any, 'ping');
+
+				// @ts-expect-error private property
+				dbConnection.scheduleNextPing();
+				jest.advanceTimersByTime(1000);
+
+				expect(pingSpy).toHaveBeenCalled();
+			} finally {
+				jest.useRealTimers();
+			}
+		});
 	});
 });

packages/cli/src/databases/db-connection-options.ts

@@ -131,6 +131,9 @@ export class DbConnectionOptions {
 			migrations: postgresMigrations,
 			connectTimeoutMS: postgresConfig.connectionTimeoutMs,
 			ssl,
+			extra: {
+				idleTimeoutMillis: postgresConfig.idleTimeoutMs,
+			},
 		};
 	}
 

packages/cli/src/databases/db-connection.ts

@@ -1,4 +1,5 @@
 import { inTest } from '@n8n/backend-common';
+import { DatabaseConfig } from '@n8n/config';
 import type { Migration } from '@n8n/db';
 import { wrapMigration } from '@n8n/db';
 import { Memoized } from '@n8n/decorators';
@@ -7,6 +8,8 @@ import { DataSource } from '@n8n/typeorm';
 import { ErrorReporter } from 'n8n-core';
 import { DbConnectionTimeoutError, ensureError } from 'n8n-workflow';
 
+import { Time } from '@/constants';
+
 import { DbConnectionOptions } from './db-connection-options';
 
 type ConnectionState = {
@@ -28,6 +31,7 @@ export class DbConnection {
 	constructor(
 		private readonly errorReporter: ErrorReporter,
 		private readonly connectionOptions: DbConnectionOptions,
+		private readonly databaseConfig: DatabaseConfig,
 	) {
 		this.dataSource = new DataSource(this.options);
 		Container.set(DataSource, this.dataSource);
@@ -80,9 +84,12 @@ export class DbConnection {
 		}
 	}
 
-	/** Ping DB connection every 2 seconds */
+	/** Ping DB connection every `pingIntervalSeconds` seconds to check if it is still alive. */
 	private scheduleNextPing() {
-		this.pingTimer = setTimeout(async () => await this.ping(), 2000);
+		this.pingTimer = setTimeout(
+			async () => await this.ping(),
+			this.databaseConfig.pingIntervalSeconds * Time.seconds.toMilliseconds,
+		);
 	}
 
 	private async ping() {