refactor(core): Port concurrency config (#18324)

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

@@ -11,6 +11,21 @@ class PruningIntervalsConfig {
 	softDelete: number = 60;
 }
 
+@Config
+class ConcurrencyConfig {
+	/**
+	 * Max production executions allowed to run concurrently. `-1` means unlimited.
+	 *
+	 * Default for scaling mode is taken from the worker's `--concurrency` flag.
+	 */
+	@Env('N8N_CONCURRENCY_PRODUCTION_LIMIT')
+	productionLimit: number = -1;
+
+	/** Max evaluation executions allowed to run concurrently. `-1` means unlimited. */
+	@Env('N8N_CONCURRENCY_EVALUATION_LIMIT')
+	evaluationLimit: number = -1;
+}
+
 @Config
 export class ExecutionsConfig {
 	/** Whether to delete past executions on a rolling basis. */
@@ -38,4 +53,7 @@ export class ExecutionsConfig {
 
 	@Nested
 	pruneDataIntervals: PruningIntervalsConfig;
+
+	@Nested
+	concurrency: ConcurrencyConfig;
 }

packages/@n8n/config/test/config.test.ts

@@ -310,6 +310,10 @@ describe('GlobalConfig', () => {
 				hardDelete: 15,
 				softDelete: 60,
 			},
+			concurrency: {
+				productionLimit: -1,
+				evaluationLimit: -1,
+			},
 		},
 		diagnostics: {
 			enabled: true,