Job selection policy

When running a node, you can choose which jobs you want to run by using configuration options, environment variables or flags to specify a job selection policy.

setting-up/networking-instructions/networking.md

Job selection probes

If you want more control over making the decision to take on jobs, you can use the --job-selection-probe-exec and --job-selection-probe-http flags.

These are external programs that are passed the following data structure so that they can make a decision about whether or not to take on a job:

{
  "node_id": "XXX",
  "job_id": "XXX",
  "spec": {
    "engine": "docker",
    "verifier": "ipfs",
    "job_spec_vm": {
      "image": "ubuntu:latest",
      "entrypoint": ["cat", "/file.txt"]
    },
    "inputs": [{
      "engine": "ipfs",
      "cid": "XXX",
      "path": "/file.txt"
    }]
  }
}

The exec probe is a script to run that will be given the job data on stdin, and must exit with status code 0 if the job should be run.

The http probe is a URL to POST the job data to. The job will be rejected if the HTTP request returns a non-positive status code (e.g. >= 400).

If the HTTP response is a JSON blob, it should match the following schema and will be used to respond to the bid directly:

{
  "$schema": "http://json-schema.org/draft-04/schema#",
  "type": "object",
  "properties": {
    "shouldBid": {
      "description": "If the job should be accepted",
      "type": "boolean"
    },
    "shouldWait": {
      "description": "If the node should wait for an async response that will come later. `shouldBid` will be ignored",
      "type": "boolean",
      "default": false,
    },
    "reason": {
      "description": "Human-readable string explaining why the job should be accepted or rejected, or why the wait is required",
      "type": "string"
    }
  },
  "required": [
    "shouldBid",
    "reason"
  ]
}

For example, the following response will reject the job:

{
  "shouldBid": false,
  "reason": "The job did not pass this specific validation: ...",
}

If the HTTP response is not a JSON blob, the content is ignored and any non-error status code will accept the job.