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NodeJs Bull for Background tasks

I have been using Bull for background tasks in my node application.

https://github.com/OptimalBits/bull

Now that node is single threaded by nature. Does bull use the same thread on which node application is running or it forks another thread and runs as a separate instance?

Solution

  • From bull quick guide:

    The process function can also be run1 in a separate process. This has several advantages:

    • The process is sandboxed so if it crashes it does not affect the worker.
    • You can run blocking code without affecting the queue (jobs will not stall).
    • Much better utilization of multi-core CPUs.
    • Less connections to redis.

    In order to use this feature just create a separate file with the processor:

    // processor.js
module.exports = function(job){
  // Do some heavy work

  return Promise.resolve(result);
}

    And define the processor like this:

    // Single process:
queue.process('/path/to/my/processor.js');

// You can use concurrency as well:
queue.process(5, '/path/to/my/processor.js');

// and named processors:
queue.process('my processor', 5, '/path/to/my/processor.js');

    1. This indicates, naturally bull doesn't create separate process for execution.

    Basic guides: https://github.com/OptimalBits/bull#separate-processes