Elasticsearch Reindex

Elasticsearch Reindex

Opster Team

March 2021


In addition to reading this guide, we recommend you run the Elasticsearch Health Check-Up. It will detect issues and improve your Elasticsearch performance by analyzing your shard sizes, threadpools, memory, snapshots, disk watermarks and more.

The Elasticsearch Check-Up is free and requires no installation.

Run the Elasticsearch check-up to receive recommendations like this:

checklist Run Check-Up
error

The following configuration error was detected on node 123...

error-img

Description

This error can have a severe impact on your system. It's important to understand that it was caused by...

error-img

Recommendation

In order to resolve this issue and prevent it from occurring again, we recommend that you begin by changing the configuration to...

1

X-PUT curl -H "Content-Type: application/json" [customized recommendation]

Overview

Reindex is the concept of copying existing data from a source index to a destination index which can be inside the same or a different cluster. Elasticsearch has a dedicated endpoint _reindex for this purpose. A reindexing is mostly required for updating mapping or settings.

Examples

Reindex data from a source index to destination index in the same cluster

POST /_reindex?pretty
{
  "source": {
    "index": "news"
  },
  "dest": {
    "index": "news_v2"
  }
}

Notes

  • Reindex API does not copy settings and mappings from the source index to the destination index. You need to create the destination index with the desired settings and mappings before you begin the reindexing process.
  • The API exposes an extensive list of configuration options to fetch data from the source index, such as query-based indexing and selecting multiple indices as the source index.
  • In some scenarios reindex API is not useful, where reindexing requires complex data processing and data modification based on application logic. In this case, you can write your custom script using Elasticsearch scroll API to fetch the data from source index and bulk API to index data into destination index.

Related log errors to this ES concept


Giving up on search because it failed with a non-retryable exception
Failed to clear scroll
Failed to shutdown the remote connection
Failed to properly stop client thread
Giving up on search because it failed with a non-retryable exception
Failed to clear scroll

Run the Check-Up to get a customized report like this:

Analyze your cluster