creating-a-worker.md

Creating a worker

The easy way

GNJ provides a few functions to ease the coding of workers.

{% code title="worker.ts/js" %}

const job = await checkForJobs({
  typeList: ['myJobType'],
  uri,
  processingFunction: async (job) => {
    const result = await myApiCall()
    return myProcessingFunction(result)
  }
})

{% endcode %}

• typeList (Array<String>) is the type of jobs the worker will wait to execute.
• uri (String) is the URL of your GraphQL endpoint.
• processingFunction (Function(job, facilities) => Promise<JsonObject>) is the function that executes the job.
• workerId = undefined
• looping = true
• loopTime = 1000

When processingFunction return something, the job is considered as done. The returned Object is serialized and stored as the "output" of the job.

Easy debug without looping

With the looping option to false the worker will only check for a job once. Made for end-to-end tests or manual debugging.

{% code title="worker.ts/js" %}

const job = await checkForJobs({
  ...,
  processingFunction: ...,
  looping: false
})

{% endcode %}

Facilities

updateProcessingInfo

{% code title="worker.ts/js" %}

const job = await checkForJobs({
  typeList: ['myJobType'],
  uri,
  processingFunction: async (job, { updateProcessingInfo }) => {
    await updateProcessingInfo({ percent: 10 })
  },
  looping: false
})

{% endcode %}

Avoiding spamming your API

Some jobs runs very rarely, so you may want that your worker only check the queue from time to time.

{% code title="worker.ts/js" %}

const job = await checkForJobs({
  ...,
  processingFunction: ...,
  loopTime: 60 * 1000 // Every minute
})

{% endcode %}

Identifying workers

GNJ automatically generated uuid for your new workers to easily track what went wrong. But if you need to link a run to an id your want you can just specify it under the workerId property**.**

{% code title="worker.ts/js" %}

const job = await checkForJobs({
  ...,
  processingFunction: ...,
  workerId: 'manualCallPreMigration'
})

{% endcode %}

They all use the GraphQL api provided by the server. So even if it's really convenient to use those functions you can create your own.