fix: add rate limit for Tiles findSingleRow action

Author: kevinkim-ogp

packages/backend/src/apps/tiles/index.ts

@@ -3,6 +3,7 @@ import { IApp } from '@plumber/types'
 import getTransferDetails from './common/get-transfer-details'
 import actions from './actions'
 import dynamicData from './dynamic-data'
+import queue from './queue'
 
 const app: IApp = {
   name: 'Tiles',
@@ -17,6 +18,7 @@ const app: IApp = {
   actions,
   dynamicData,
   getTransferDetails,
+  queue,
 }
 
 export default app

packages/backend/src/apps/tiles/queue/index.ts

@@ -0,0 +1,48 @@
+import type { IAppQueue } from '@plumber/types'
+
+import { TILES_INTERVAL_BETWEEN_FIND_SINGLE_ROW_MS } from '@/config/app-env-vars/tiles'
+import Step from '@/models/step'
+
+// Define actions that should be queued
+const QUEUED_ACTIONS = new Set(['findSingleRow'])
+
+//
+// This config sets up a per-Tile findSingleRow action queue, i.e., only findSingleRow
+// actions are grouped and rate limited.
+// All other Tile actions are not grouped and do not need to be rate limited.
+//
+// This is necessary because the findSingleRow action is the most expensive
+// operation in the Tile app, due to the need to scan the entire DynamoDB table.
+//
+
+const getGroupConfigForJob: IAppQueue['getGroupConfigForJob'] = async (
+  jobData,
+) => {
+  const step = await Step.query().findById(jobData.stepId).throwIfNotFound()
+  const tableId = step.parameters['tableId'] as string
+
+  if (QUEUED_ACTIONS.has(step.key)) {
+    return {
+      id: `${tableId}-${step.key}`,
+    }
+  }
+
+  // All other Tile actions are not grouped and do not need to be rate limited
+  // as the write operations are fast and less expensive.
+  return null
+}
+
+const queueSettings = {
+  getGroupConfigForJob,
+  groupLimits: {
+    type: 'concurrency',
+    concurrency: 1,
+  },
+  isQueueDelayable: true,
+  queueRateLimit: {
+    max: 1,
+    duration: TILES_INTERVAL_BETWEEN_FIND_SINGLE_ROW_MS,
+  },
+} satisfies IAppQueue
+
+export default queueSettings

packages/backend/src/config/app-env-vars/index.ts

@@ -24,3 +24,4 @@
 import './m365'
 import './formsg'
 import './postman-sms'
+import './tiles'

packages/backend/src/config/app-env-vars/tiles.ts

@@ -0,0 +1,4 @@
+// Default to 1 action per second.
+export const TILES_INTERVAL_BETWEEN_FIND_SINGLE_ROW_MS = Number(
+  process.env.TILES_INTERVAL_BETWEEN_FIND_SINGLE_ROW_MS ?? '1000',
+)