Elasticsearch Elasticsearch Delete By ID: Advanced Usage and Best Practices

By Opster Team

Updated: Nov 2, 2023

| 3 min read

Introduction

Deleting documents in Elasticsearch is a common operation that can be performed using the Delete API. This API allows you to delete a single document by specifying its unique ID. In this article, we will discuss advanced usage and best practices for using the Elasticsearch Delete By ID API. If you want to learn about Elasticsearch delete by query, check out this guide.

1. Using the Delete By ID API

To delete a document by its ID, you can use the following syntax:

DELETE /<index>/_doc/<document_id>

Replace `<index>` with the name of the index containing the document, and `<document_id>` with the unique ID of the document you want to delete.

For example, to delete a document with the ID `1` from the `my_index` index, you would use the following command:

DELETE /my_index/_doc/1

2. Handling Version Conflicts

When deleting a document by ID, you might encounter version conflicts if the document has been updated concurrently. To handle version conflicts, you can use the `version` and `version_type` parameters.

The `version` parameter specifies the expected version of the document, while the `version_type` parameter can be set to `external` or `external_gte` to control how Elasticsearch handles version conflicts.

For example, to delete a document with the ID `1` and an expected version of `2`, you would use the following command:

DELETE /my_index/_doc/1?version=2&version_type=external

3. Using the Refresh Parameter

By default, Elasticsearch does not immediately make the deleted document unavailable for search. Instead, it marks the document as deleted and removes it during the next segment merge. To force Elasticsearch to refresh the index immediately after deleting the document, you can use the `refresh` parameter.

For example, to delete a document with the ID `1` and refresh the index immediately, you would use the following command:

DELETE /my_index/_doc/1?refresh=true

Keep in mind that using the `refresh` parameter frequently can negatively impact the performance of your Elasticsearch cluster.

4. Deleting Documents in Bulk

If you need to delete multiple documents by their IDs, you can use the Bulk API. This API allows you to perform multiple delete operations in a single request, which can significantly improve performance.

To use the Bulk API, you need to create a request body containing the delete operations, each specified by a JSON object with a `delete` action and the document’s metadata.

For example, to delete documents with the IDs `1` and `2` from the `my_index` index, you would use the following command:

POST /_bulk
{"delete": {"_index": "my_index", "_id": "1"}}
{"delete": {"_index": "my_index", "_id": "2"}}

5. Deleting Documents Using A Query By ID

Similarly to the previous method, you can also delete multiple documents by their IDs using the DeleteByQuery API. This API accepts a query and deletes all documents that match that query in a single request, which also significantly improves the performance.

For example, to delete documents with the IDs `1` and `2` from the `my_index` index, you would use the following command:

POST my_index/_delete_by_query
{
  "query": {
    "ids": {
      "values": ["1", "2"]
    }
  }
}

6. Monitoring Delete Operations

To monitor the progress of delete operations in your Elasticsearch cluster, you can use the Task Management API. This API allows you to retrieve information about ongoing and completed tasks, including delete operations.

For example, to retrieve information about all delete operations, you would use the following command:

GET /_tasks?actions=*delete*

7. Best Practices for Deleting Documents

When using the Delete By ID API, consider the following best practices:

• Avoid using the `refresh` parameter frequently, as it can negatively impact performance.
• Use the Bulk API or the DeleteByQuery API for deleting multiple documents to improve performance.
• Monitor delete operations using the Task Management API to ensure they complete successfully.
• Handle version conflicts using the `version` and `version_type` parameters to prevent data loss.

Conclusion 

In conclusion, the Elasticsearch Delete By ID API is a powerful tool for managing documents in your cluster. By following the advanced usage techniques and best practices discussed in this article, you can ensure efficient and reliable delete operations in your Elasticsearch environment.