queue

const connection = new IORedis({
  host:     process.env.REDIS_QUEUE_HOST,
  port:     Number(process.env.REDIS_QUEUE_PORT),
  username: process.env.REDIS_QUEUE_USER,
  password: process.env.REDIS_QUEUE_PASS,
  family:   0,
  maxRetriesPerRequest: null,
});

cache
export const cacheRedis = new Redis({
  host:     process.env.REDIS_CACHE_HOST,
  port:     Number(process.env.REDIS_CACHE_PORT),
  username: process.env.REDIS_CACHE_USER,
  password: process.env.REDIS_CACHE_PASS,
  family:   0,
  maxRetriesPerRequest: null,
  enableAutoPipelining: true,
});

railway shell ➜ manual ping:

root@f0d6a37b83bf:/app# node -e "import('ioredis').then(({default:r})=>new r({
  host:process.env.REDIS_QUEUE_HOST,
  port:process.env.REDIS_QUEUE_PORT,
  username:process.env.REDIS_QUEUE_USER,
  password:process.env.REDIS_QUEUE_PASS,
  family:0}).ping().then(console.log))"
PONG
root@f0d6a37b83bf:/app# node -e "import('ioredis').then(({default:r})=>new r({
  host:process.env.REDIS_CACHE_HOST,
  port:process.env.REDIS_CACHE_PORT,
  username:process.env.REDIS_CACHE_USER,
  password:process.env.REDIS_CACHE_PASS,
  family:0}).ping().then(console.log))"
PONG

During runtime the app still logs:
Error: connect ECONNREFUSED 127.0.0.1:6379
    at TCPConnectWrap.afterConnect [as oncomplete] (node:net:1555:16) {
  errno: -111,
  code: 'ECONNREFUSED',
  syscall: 'connect',
  address: '127.0.0.1',
  port: 6379
}
Removed all REDIS_QUEUE_URL / REDIS_CACHE_URL variables – only host/port/user/pass remain.
Added family: 0 to ioredis options.
Searched the codebase for any leftover localhost or 127.0.0.1 references – none found.
Re-deployed multiple times.

Is there any place in Railway build/runtime that may inject a default REDIS_HOST=127.0.0.1 or override env vars?

Could you check if the internal DNS names (redis-bullmq.railway.internal, redis-cache.railway.internal) resolve to IPv6 only and if any extra flag is needed with ioredis 5.x?

Any debugging hook to see what exact Redis connection string BullMQ receives at runtime?

Thanks in advance – happy to provide deployment ID or full logs on request.