ioredis throws an error that i cannot catch and make p3x-redis-server (p3x-redis-ui) crash

[p3x-robot]

hello!

what happening is that if a user configure a redis settings wrong, there is an error, that i cannot catch.
the error is like this:

[P3XRS] [PID: 018665]  Trace
    at parseType (/home/patrikx3/Projects/patrikx3/redis-ui-workspace/redis-ui-server/node_modules/redis-parser/lib/parser.js:302:17)
    at JavascriptRedisParser.execute (/home/patrikx3/Projects/patrikx3/redis-ui-workspace/redis-ui-server/node_modules/redis-parser/lib/parser.js:534:24)
    at Socket.<anonymous> (/home/patrikx3/Projects/patrikx3/redis-ui-workspace/redis-ui-server/node_modules/ioredis/built/DataHandler.js:25:20)
    at Socket.emit (events.js:315:20)
    at addChunk (internal/streams/readable.js:309:12)
    at readableAddChunk (internal/streams/readable.js:284:9)
    at Socket.Readable.push (internal/streams/readable.js:223:10)
    at TCP.onStreamRead (internal/stream_base_commons.js:188:23)
    at TCP.callbackTrampoline (internal/async_hooks.js:131:14)
[P3XRS] [PID: 018665]  3/27/2021, 6:19:33 AM unhandledRejection ReplyError: ERR SELECT is not allowed in cluster mode
    at parseError (/home/patrikx3/Projects/patrikx3/redis-ui-workspace/redis-ui-server/node_modules/redis-parser/lib/parser.js:179:12)
    at parseType (/home/patrikx3/Projects/patrikx3/redis-ui-workspace/redis-ui-server/node_modules/redis-parser/lib/parser.js:303:14) {
  command: { name: 'select', args: [ '1' ] }
} Promise {
  <rejected> ReplyError: ERR SELECT is not allowed in cluster mode
      at parseError (/home/patrikx3/Projects/patrikx3/redis-ui-workspace/redis-ui-server/node_modules/redis-parser/lib/parser.js:179:12)
      at parseType (/home/patrikx3/Projects/patrikx3/redis-ui-workspace/redis-ui-server/node_modules/redis-parser/lib/parser.js:303:14) {
    command: { name: 'select', args: [Array] }
  }
}

so if the user creates a setting for a non cluster that is actually a cluster this error happening and there is no way to catch, so my app crashes.
please let me know how i can disable this automatic select 1 command, when you are connecting to a clustered redis instance but with wrong connection, without enabling cluster mode.

[luin]

Hi @p3x-robot , I'm not sure where the select command was sent. Can you enable showFriendlyErrorStack and post the error stack here? Thanks!

[p3x-robot]

redisConfig.showFriendlyErrorStack = true

it is happening, when i set the redisConfig.db = db => new Redis(redisConfig)

it happens, when a user wrong configuration sets (eg. the server is cluster, but the config is not in cluster mode)

[P3XRS] [PID: 024551]  3/27/2021, 7:05:54 AM unhandledRejection ReplyError: ERR SELECT is not allowed in cluster mode
    at Object.onceWrapper (events.js:421:28)
    at Socket.emit (events.js:327:22)
    at TCPConnectWrap.afterConnect [as oncomplete] (net.js:1132:10)
    at TCPConnectWrap.callbackTrampoline (internal/async_hooks.js:131:14) {
  command: { name: 'select', args: [ '1' ] }
} Promise {
  <rejected> ReplyError: ERR SELECT is not allowed in cluster mode
      at Object.onceWrapper (events.js:421:28)
      at Socket.emit (events.js:327:22)
      at TCPConnectWrap.afterConnect [as oncomplete] (net.js:1132:10)
      at TCPConnectWrap.callbackTrampoline (internal/async_hooks.js:131:14) {
    command: { name: 'select', args: [Array] }
  }
}

[p3x-robot]

the problam is i cannot catch this error, uncoverable.

[luin]

Hmm, strange. The stack doesn't give any useful information. Is there a way I can reproduce the issue? I downloaded the electron package from https://github.com/patrikx3/redis-ui/releases but can't reproduce it. My steps:

1. Setup a redis cluster with docker: docker run -e "IP=0.0.0.0" -p 7000-7005:7000-7005 grokzen/redis-cluster:latest
2. Add a connection in P3X Redis UI. Port is 7000
3. Click the refresh button on the upper right.

[p3x-robot]

@luin :

set like this:

(make sure it is an error, disable cluster)

then connect to it, then on the home, select a database like 10. then refresh the browser, it will try to connect to database 10, then it crashes.
it is becuase we are using [redisconfig.db = 10 => new Redis(redisconfig) ]

[p3x-robot]

ok, i solved it, with a different solution, but this errror exists... if you do not want to care about i can close it for you.

[luin]

I can finally reproduce this. How did you solve the issue? Regarding the solution, my current idea is to emit an error event and then ignore the failed select command (i.e. even if db: 10 is set, db 0 will still be connected). What do you think?

[p3x-robot]

i disabled on the connection and when the gui reads the keys via scan, before, i call select ${db} and i silently hide the error if it is unable to set the database.

but what it is in the redisConfig.db is not usable right now and cannot be able to catch the error. i do no know which is the best solution, it is up to you.

[p3x-robot]

yes i think it is a good solution to emit an error event, sure.

[ioredis-robot]

🎉 This issue has been resolved in version 4.24.5 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot 📦🚀

[p3x-robot]

thanks very much!