replace redis client library with ioredis

packages/rss-handler/package.json

@@ -27,9 +27,9 @@
     "@sentry/serverless": "^7.77.0",
     "axios": "^1.4.0",
     "dotenv": "^16.0.1",
+    "ioredis": "^5.3.2",
     "jsonwebtoken": "^8.5.1",
     "linkedom": "^0.16.4",
-    "redis": "^4.3.1",
     "rss-parser": "^3.13.0"
   },
   "volta": {

packages/rss-handler/src/index.ts

@@ -2,17 +2,15 @@ import * as Sentry from '@sentry/serverless'
 import axios from 'axios'
 import crypto from 'crypto'
 import * as dotenv from 'dotenv' // see https://github.com/motdotla/dotenv#how-do-i-use-dotenv-with-import
+import Redis from 'ioredis'
 import * as jwt from 'jsonwebtoken'
 import { parseHTML } from 'linkedom'
-import { createClient } from 'redis'
 import Parser, { Item } from 'rss-parser'
 import { promisify } from 'util'
 import { createRedisClient } from './redis'
 import { CONTENT_FETCH_URL, createCloudTask } from './task'
 
 type FolderType = 'following' | 'inbox'
-// explicitly create the return type of RedisClient
-type RedisClient = ReturnType<typeof createClient>
 
 interface RssFeedRequest {
   subscriptionIds: string[]
@@ -61,7 +59,7 @@ export const isOldItem = (item: RssFeedItem, lastFetchedAt: number) => {
 const feedFetchFailedRedisKey = (feedUrl: string) =>
   `feed-fetch-failure:${feedUrl}`
 
-const isFeedBlocked = async (feedUrl: string, redisClient: RedisClient) => {
+const isFeedBlocked = async (feedUrl: string, redisClient: Redis) => {
   const key = feedFetchFailedRedisKey(feedUrl)
   try {
     const result = await redisClient.get(key)
@@ -78,10 +76,7 @@ const isFeedBlocked = async (feedUrl: string, redisClient: RedisClient) => {
   return false
 }
 
-const incrementFeedFailure = async (
-  feedUrl: string,
-  redisClient: RedisClient
-) => {
+const incrementFeedFailure = async (feedUrl: string, redisClient: Redis) => {
   const key = feedFetchFailedRedisKey(feedUrl)
   try {
     const result = await redisClient.incr(key)
@@ -259,7 +254,7 @@ const sendUpdateSubscriptionMutation = async (
 }
 
 const isItemRecentlySaved = async (
-  redisClient: RedisClient,
+  redisClient: Redis,
   userId: string,
   url: string
 ) => {
@@ -274,7 +269,7 @@ const createTask = async (
   item: RssFeedItem,
   fetchContent: boolean,
   folder: FolderType,
-  redisClient: RedisClient
+  redisClient: Redis
 ) => {
   const isRecentlySaved = await isItemRecentlySaved(
     redisClient,
@@ -464,7 +459,7 @@ const processSubscription = async (
   fetchContent: boolean,
   folder: FolderType,
   feed: RssFeed,
-  redisClient: RedisClient
+  redisClient: Redis
 ) => {
   let lastItemFetchedAt: Date | null = null
   let lastValidItem: RssFeedItem | null = null
@@ -606,7 +601,7 @@ export const rssHandler = Sentry.GCPFunction.wrapHttpFunction(
     }
 
     // create redis client
-    const redisClient = await createRedisClient(
+    const redisClient = createRedisClient(
       process.env.REDIS_URL,
       process.env.REDIS_CERT
     )

packages/rss-handler/src/redis.ts

@@ -1,26 +1,34 @@
-import { createClient } from 'redis'
+import { Redis } from 'ioredis'
 
-export const createRedisClient = async (url?: string, cert?: string) => {
-  const redisClient = createClient({
-    url,
-    socket: {
-      tls: url?.startsWith('rediss://'), // rediss:// is the protocol for TLS
-      cert: cert?.replace(/\\n/g, '\n'), // replace \n with new line
-      rejectUnauthorized: false, // for self-signed certs
-      connectTimeout: 10000, // 10 seconds
-      reconnectStrategy(retries: number): number | Error {
-        if (retries > 10) {
-          return new Error('Retries exhausted')
+export const createRedisClient = (url?: string, cert?: string) => {
+  return new Redis(url || 'redis://localhost:6379', {
+    connectTimeout: 10000, // 10 seconds
+    tls: cert
+      ? {
+          cert,
+          rejectUnauthorized: false, // for self-signed certs
         }
-        return 1000
-      },
+      : undefined,
+    reconnectOnError: (err) => {
+      const targetErrors = [/READONLY/, /ETIMEDOUT/]
+
+      targetErrors.forEach((targetError) => {
+        if (targetError.test(err.message)) {
+          // Only reconnect when the error contains the keyword
+          return true
+        }
+      })
+
+      return false
+    },
+    retryStrategy: (times) => {
+      if (times > 10) {
+        // End reconnecting after a specific number of tries and flush all commands with a individual error
+        return null
+      }
+
+      // reconnect after
+      return Math.min(times * 50, 2000)
     },
   })
-
-  redisClient.on('error', (err) => console.error('Redis Client Error', err))
-
-  await redisClient.connect()
-  console.log('Redis Client Connected:', url)
-
-  return redisClient
 }