opensearch-docs-cn/_clients/javascript/helpers.md

layout	title	parent	nav_order
default	Helper methods	JavaScript client	2

Helper methods

Helper methods simplify the use of complicated API tasks.

Bulk helper

The bulk helper simplifies making complex bulk API requests.

Usage

The following code creates a bulk helper instance:

const { Client } = require('@opensearch-project/opensearch')
const documents = require('./docs.json')

const client = new Client({ ... })

const result = await client.helpers.bulk({
  datasource: documents,
  onDocument (doc) {
    return {
      index: { _index: 'example-index' }
    }
  }
})

console.log(result)

{% include copy.html %}

Bulk helper operations return an object with the following fields:

{
  total: number,
  failed: number,
  retry: number,
  successful: number,
  time: number,
  bytes: number,
  aborted: boolean
}

Bulk helper configuration options

When creating a new bulk helper instance, you can use the following configuration options.

Option	Data type	Required/Default	Description
datasource	An array, async generator or a readable stream of strings or objects	Required	Represents the documents you need to create, delete, index, or update.
onDocument	Function	Required	A function to be invoked with each document in the given datasource. It returns the operation to be executed for this document. Optionally, the document can be manipulated for create and index operations by returning a new document as part of the function's result.
concurrency	Integer	Optional. Default is 5.	The number of requests to be executed in parallel.
flushBytes	Integer	Optional. Default is 5,000,000.	Maximum bulk body size to send in bytes.
flushInterval	Integer	Optional. Default is 30,000.	Time in milliseconds to wait before flushing the body after the last document has been read.
onDrop	Function	Optional. Default is noop.	A function to be invoked for every document that can’t be indexed after reaching the maximum number of retries.
refreshOnCompletion	Boolean	Optional. Default is false.	Whether or not a refresh should be run on all affected indexes at the end of the bulk operation.
retries	Integer	Optional. Defaults to the client's maxRetries value.	The number of times an operation is retried before onDrop is called for that document.
wait	Integer	Optional. Default is 5,000.	Time in milliseconds to wait before retrying an operation.

Examples

The following examples illustrate the index, create, update, and delete bulk helper operations.

Index

The index operation creates a new document if it doesn’t exist and recreates the document if it already exists.

The following bulk operation indexes documents into example-index:

client.helpers.bulk({
  datasource: arrayOfDocuments,
  onDocument (doc) {
    return {
      index: { _index: 'example-index' }
    }
  }
})

{% include copy.html %}

The following bulk operation indexes documents into example-index with document overwrite:

client.helpers.bulk({
  datasource: arrayOfDocuments,
  onDocument (doc) {
    return [
      {
        index: { _index: 'example-index' }
      },
      { ...doc, createdAt: new Date().toISOString() }
    ]
  }
})

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Create

The create operation creates a new document only if the document does not already exist.

The following bulk operation creates documents in the example-index:

client.helpers.bulk({
  datasource: arrayOfDocuments,
  onDocument (doc) {
    return {
      create: { _index: 'example-index', _id: doc.id }
    }
  }
})

{% include copy.html %}

The following bulk operation creates documents in the example-index with document overwrite:

client.helpers.bulk({
  datasource: arrayOfDocuments,
  onDocument (doc) {
    return [
      {
        create: { _index: 'example-index', _id: doc.id }
      },
      { ...doc, createdAt: new Date().toISOString() }
    ]
  }
})

{% include copy.html %}

Update

The update operation updates the document with the fields being sent. The document must already exist in the index.

The following bulk operation updates documents in the arrayOfDocuments:

client.helpers.bulk({
  datasource: arrayOfDocuments,
  onDocument (doc) {
    // The update operation always requires a tuple to be returned, with the
    // first element being the action and the second being the update options.
    return [
      {
        update: { _index: 'example-index', _id: doc.id }
      },
      { doc_as_upsert: true }
    ]
  }
})

{% include copy.html %}

The following bulk operation updates documents in the arrayOfDocuments with document overwrite:

client.helpers.bulk({
  datasource: arrayOfDocuments,
  onDocument (doc) {
    return [
      {
        update: { _index: 'example-index', _id: doc.id }
      },
      {
        doc: { ...doc, createdAt: new Date().toISOString() },
        doc_as_upsert: true
      }
    ]
  }
})

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Delete

The delete operation deletes a document.

The following bulk operation deletes documents from the example-index:

client.helpers.bulk({
  datasource: arrayOfDocuments,
  onDocument (doc) {
    return {
      delete: { _index: 'example-index', _id: doc.id }
    }
  }
})

{% include copy.html %}