CODEWITHSUNDEEP
node.jsamazon-web-servicesamazon-ec2redisamazon-elasticache
Mr.X
Mr.X

Reputation: 31335

How to connect to ElastiCache cluster using node.js

We know that ElastiCache is not recommended to be accessed outside Amazon instances, so we're trying below stuff inside Amazon EC2 instances only.

We've got a ElastiCache Redis Cluster with 9 nodes. When we try to connect to it using normal redis implementation, it throws some Moved errors

Have tried the retry strategy method as per @Miller. Have also tried RedisCluster with unstable and stable (poor man) implementations.

None of these implementations are working. Any suggestions please?

Upvotes: 25

Views: 26232

Answers (3)

tomnyson
tomnyson

Reputation: 297

const redisClient = process.env.NODE_ENV === 'production'
  ? new Redis.Cluster(
    [
      {
        host: 'node-production-0001-001.b2tyw0.0001.use2.cache.amazonaws.com',
        port: 6379,
        flags: 'master'
      },
      {
        host: 'node-production-0001-002.b2tyw0.0001.use2.cache.amazonaws.com',
        port: 6379,
        flags: 'slave'
      },
      {
        host: 'node-production-0001-003.b2tyw0.0001.use2.cache.amazonaws.com',
        port: 6379,
        flags: 'slave'
      },
    ], {
      scaleReads: 'slave'
    }
  )
  : new Redis({
    host: process.env.REDIS_HOST || 'localhost',
    port: process.env.REDIS_PORT || 6379,
  });

It's work for me with enable cluster mode

Upvotes: 1

abhikedia_
abhikedia_

Reputation: 122

You can try to connect using ioredis.

var Redis = require('ioredis');
var config = require("./config.json");

const redis = new Redis({
  host: config.host,
  port: config.port,
  password: config.password, // If you have any.
  tls: {}, // Add this empty tls field.
});

redis.on('connect', () => {
  console.log('Redis client is initiating a connection to the server.');
});

redis.on('ready', () => {
  console.log('Redis client successfully initiated connection to the server.');
});

redis.on('reconnecting', () => {
  console.log('Redis client is trying to reconnect to the server...');
});

redis.on('error', (err) => console.log('Redis Client Error', err));

//check the functioning
redis.set("framework", "AngularJS", function(err, reply) {
  console.log("redis.set ", reply);
});

redis.get("framework", function(err, reply) {
  console.log("redis.get ", reply);
});

Upvotes: 1

Mr.X
Mr.X

Reputation: 31335

Sharing the code for future readers:

var RedisClustr = require('redis-clustr');
var RedisClient = require('redis');
var config = require("./config.json");

var redis = new RedisClustr({
    servers: [
        {
            host: config.redisClusterHost,
            port: config.redisClusterPort
        }
    ],
    createClient: function (port, host) {
        // this is the default behaviour
        return RedisClient.createClient(port, host);
    }
});

//connect to redis
redis.on("connect", function () {
  console.log("connected");
});

//check the functioning
redis.set("framework", "AngularJS", function (err, reply) {
  console.log("redis.set " , reply);
});

redis.get("framework", function (err, reply) {
  console.log("redis.get ", reply);
});

Upvotes: 33

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