perf: expand gateway capacity and prevent receipt replay

api/src/channels/channel-connection.service.ts

@@ -367,6 +367,10 @@ export class ChannelConnectionService {
         cmppVersion: channel.cmppVersion,
         rateLimitPerSecond: channel.rateLimitPerSecond,
         windowSize: getPositiveRuntimeInteger(getConfigValue(channel.config, 'windowSize'), 16, 'windowSize'),
+        connectionWarmupSeconds: Number(getConfigValue(channel.config, 'connectionWarmupSeconds') ?? 30),
+        connectionDrainTimeoutSeconds: getPositiveRuntimeInteger(getConfigValue(channel.config, 'connectionDrainTimeoutSeconds'), 60, 'connectionDrainTimeoutSeconds'),
+        submitResponseTimeoutSeconds: getPositiveRuntimeInteger(getConfigValue(channel.config, 'submitResponseTimeoutSeconds'), 60, 'submitResponseTimeoutSeconds'),
+        connectionFailureCooldownSeconds: getPositiveRuntimeInteger(getConfigValue(channel.config, 'connectionFailureCooldownSeconds'), 30, 'connectionFailureCooldownSeconds'),
         heartbeatIntervalSeconds: getPositiveRuntimeInteger(
           getConfigValue(channel.config, 'heartbeatIntervalSeconds'),
           DEFAULT_HEARTBEAT_INTERVAL_SECONDS,

api/src/channels/channels.helpers.capacity.spec.ts

@@ -0,0 +1,14 @@
+import { BadRequestException } from '@nestjs/common';
+import { normalizeChannelRuntimeConfig } from './channels.helpers';
+
+describe('Gateway channel capacity validation', () => {
+  it.each([1, 2, 4, 8])('accepts %i supplier connections', (desiredConnections) => {
+    expect(normalizeChannelRuntimeConfig(undefined, undefined, desiredConnections, 16)).toEqual(expect.objectContaining({ desiredConnections, windowSize: 16 }));
+  });
+  it.each([1, 16, 32, 64])('accepts supplier window %i', (windowSize) => {
+    expect(normalizeChannelRuntimeConfig(undefined, undefined, 1, windowSize)).toEqual(expect.objectContaining({ desiredConnections: 1, windowSize }));
+  });
+  it.each([[0, 16], [9, 16], [1, 0], [1, 65]])('rejects capacity outside 1..8 connections and 1..64 window', (connections, window) => {
+    expect(() => normalizeChannelRuntimeConfig(undefined, undefined, connections, window)).toThrow(BadRequestException);
+  });
+});

api/src/channels/channels.helpers.ts

@@ -228,7 +228,7 @@ export function defaultChannelConnectionId(channelId: string) {
 export function getDesiredConnections(config?: Prisma.JsonValue | null) {
   if (config && typeof config === 'object' && !Array.isArray(config) && 'desiredConnections' in config) {
     const value = Number(config.desiredConnections);
-    if (Number.isInteger(value) && value > 0) {
+    if (Number.isInteger(value) && value >= 1 && value <= 8) {
       return value;
     }
   }
@@ -327,8 +327,12 @@ export function normalizeChannelRuntimeConfig(
     ? incomingConfig
     : {};
   const base = { ...existing, ...incoming };
-  base.desiredConnections = getPositiveRuntimeInteger(desiredConnections ?? base.desiredConnections, 1, 'desiredConnections');
-  base.windowSize = getPositiveRuntimeInteger(windowSize ?? base.windowSize, 16, 'windowSize');
+  base.desiredConnections = boundedRuntimeInteger(desiredConnections ?? base.desiredConnections, 1, 8, 1, 'desiredConnections');
+  base.windowSize = boundedRuntimeInteger(windowSize ?? base.windowSize, 1, 64, 16, 'windowSize');
+  base.connectionWarmupSeconds = boundedRuntimeInteger(base.connectionWarmupSeconds, 0, 300, 30, 'connectionWarmupSeconds');
+  base.connectionDrainTimeoutSeconds = boundedRuntimeInteger(base.connectionDrainTimeoutSeconds, 1, 600, 60, 'connectionDrainTimeoutSeconds');
+  base.submitResponseTimeoutSeconds = boundedRuntimeInteger(base.submitResponseTimeoutSeconds, 1, 300, 60, 'submitResponseTimeoutSeconds');
+  base.connectionFailureCooldownSeconds = boundedRuntimeInteger(base.connectionFailureCooldownSeconds, 1, 300, 30, 'connectionFailureCooldownSeconds');
   base.heartbeatIntervalSeconds = getPositiveRuntimeInteger(
     heartbeatIntervalSeconds ?? base.heartbeatIntervalSeconds,
     DEFAULT_HEARTBEAT_INTERVAL_SECONDS,
@@ -345,6 +349,14 @@ export function normalizeChannelRuntimeConfig(
   return base;
 }
 
+function boundedRuntimeInteger(value: unknown, minimum: number, maximum: number, fallback: number, field: string) {
+  const normalized = value === undefined || value === null || value === '' ? fallback : Number(value);
+  if (!Number.isInteger(normalized) || normalized < minimum || normalized > maximum) {
+    throw new BadRequestException(`${field} must be an integer between ${minimum} and ${maximum}`);
+  }
+  return normalized;
+}
+
 export function normalizeLongMessageReceiptMode(value: unknown) {
   const normalized = String(value ?? 'per_segment').trim() || 'per_segment';
   if (!['per_segment', 'message_level'].includes(normalized)) {