slack_socket_mode_no_reply_received_error bot stopped responding with socket mode

Description

Hello we had an issue with an internal slack bot that we have written.

It stopped responding to us and when we checked the logs they were full of:

{"code":"slack_socket_mode_no_reply_received_error"}
[ERROR]  socket-mode:SocketModeClient:0 cannot send message when client is not connected
(node:1) UnhandledPromiseRejectionWarning: Error: Cannot send message when client is not connected
    at Object.sendWhileDisconnectedError (/opt/app/node_modules/@slack/socket-mode/dist/errors.js:56:26)
    at /opt/app/node_modules/@slack/socket-mode/dist/SocketModeClient.js:333:33
    at new Promise (<anonymous>)
    at SocketModeClient.send (/opt/app/node_modules/@slack/socket-mode/dist/SocketModeClient.js:329:16)
    at ack (/opt/app/node_modules/@slack/socket-mode/dist/SocketModeClient.js:466:24)
    at App.processEvent (/opt/app/node_modules/@slack/bolt/dist/App.js:424:19)
    at runMicrotasks (<anonymous>)
    at processTicksAndRejections (internal/process/task_queues.js:93:5)
    at async SocketModeClient.<anonymous> (/opt/app/node_modules/@slack/bolt/dist/receivers/SocketModeReceiver.js:90:13)

Not sure if it’s a mistake in our implementation or something lower level, any guidance welcomed,

The code can be found here: https://github.com/hmcts/slack-help-bot/blob/main/app.js

What type of issue is this? (place an x in one of the [ ])

• bug
• enhancement (feature request)
• question
• documentation related
• example code related
• testing related
• discussion

Requirements (place an x in each of the [ ])

• I’ve read and understood the Contributing guidelines and have done my best effort to follow them.
• I’ve read and agree to the Code of Conduct.
• I’ve searched for any related issues and avoided creating a duplicate issue.

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Bug Report

Filling out the following details about bugs will help us solve your issue sooner.

Reproducible in:

package version: 3.0.0

node version: v14.8.0

OS version(s): 3.11.6 NAME=“Alpine Linux”

Steps to reproduce:

1. I assume it’s to do with network connections not being handled properly but we only saw this once so far

Expected result:

bot reconnects automatically

Actual result:

bot was stuck in a disconnected state and didn’t respond to new events / messages until it was restarted

Attachments:

https://github.com/hmcts/slack-help-bot/blob/main/app.js

[timja]

@Ohiekkar I implemented this work around to have my process monitor (Kubernetes in this case) restart it if this happened: https://github.com/hmcts/slack-help-bot/pull/46

No reports of issues since implementing that

[timja]

FWIW, the underlying “ws” package has been fixing bugs in v7 minor/patch versions. If your app uses a bit old version of it, upgrading ws to the latest may be worth trying. See also: slackapi/node-slack-sdk#1322

Seems we are on:

slack-help-bot@1.0.0 /Users/timja/projects/hmcts/slack-help-bot ├─┬ @slack/bolt@3.6.0 │ └─┬ @slack/socket-mode@1.1.0 │ └── ws@7.4.2 └─┬ jest@26.6.3 └─┬ @jest/core@26.6.3 └─┬ jest-config@26.6.3 └─┬ jest-environment-jsdom@26.6.2 └─┬ jsdom@16.4.0 └── ws@7.4.2 deduped

A little bit lower than the minimum version here: https://github.com/slackapi/node-slack-sdk/pull/1322/files, but either needs a resolution entry or a bump here I think? Is there any reason you aren’t using the 8.x version?