Bull pause/resume bug reproduce

A minimal-ish example demonstrating a pause/resume bug in Bull.

Prerequisites

• Docker

Usage

The bug this code is attempting to demonstrate occurs infrequently. This repository uses a sneaky patch on top of ioredis that delays the resolution of the promise returned by the Redis cluster client's quit() funcion a tiny bit. This makes the bug pop up a lot more often.

Note also that this package depends on an unofficial version of ioredis: It is version 5.3.2 with this fix applied. Nevertheless, the steps below apply equally well to the original version 5.3.2 as well - all that is needed is to change the version of ioredis in package.json to 5.3.2, then remove node_modules and re-run npm install before performing the steps below.

To observe the bug in action, perform the following steps:

1. Make a clone of this repository.
2. Remove patches/bull+4.12.2.patch.
3. Run npm ci.
4. Run npm start.

The output should look roughly like this:

$ npm start

> bull-pause-resume-bug@1.0.0 start
> docker compose up test-runner

[+] Running 2/2
 ✔ Container redis-cluster
 ✔ Container test-runner
Attaching to test-runner
test-runner  | Waiting 5 seconds to give the Redis cluster a moment :P
test-runner  | Creating Redis client client
test-runner  | Creating Redis client bclient
test-runner  | Creating Redis client subscriber
test-runner  | Processing jobs now
test-runner  | Received a job with data { foo: 'bar' }
test-runner  | Received a job with data { foo: 'bar' }
test-runner  | Received a job with data { foo: 'bar' }
test-runner  | Received a job with data { foo: 'bar' }
test-runner  | Received a job with data { foo: 'bar' }
test-runner  | Received a job with data { foo: 'bar' }
test-runner  | Received a job with data { foo: 'bar' }
test-runner  | Queue paused
test-runner  | Received a job with data { foo: 'bar' }
test-runner  | Queue resumed
test-runner  | Received a job with data { foo: 'initial bar' }
test-runner  | Received a job with data { foo: 'bar' }
test-runner  | Received a job with data { foo: 'bar' }
test-runner  | Received a job with data { foo: 'bar' }
test-runner  | Received a job with data { foo: 'bar' }
test-runner  | Received a job with data { foo: 'bar' }
test-runner  | Received a job with data { foo: 'bar' }
test-runner  | /app/node_modules/ioredis/built/cluster/index.js:124
test-runner  |                     reject(new redis_errors_1.RedisError("Connection is aborted"));
test-runner  |                            ^
test-runner  |
test-runner  | RedisError: Connection is aborted
test-runner  |     at /app/node_modules/ioredis/built/cluster/index.js:124:28
test-runner  |
test-runner  | Node.js v20.11.1
test-runner exited with code 1

To see the fix in action, perform the following steps:

1. git checkout patches/bull+4.12.2.patch.
2. Run npm ci.
3. Run npm start.

The test runner should no longer crash as it did before.