Elasticsearch Scroll

Elasticsearch Scroll

Last Update: March 2020

Before you start reading this page, try the new Elasticsearch Check-Up - Get actionable recommendations that can improve your cluster search and indexing speed (no installation required).

Scroll in Elasticsearch

What it is

In Elasticsearch, the concept of scroll comes into play when you have a large set of search results. Large search results are exhaustive for both the Elasticsearch cluster and the requesting client in terms of memory and processing. The scroll API enables you  to take a snapshot of a large number of results from a single search request.

Examples

To perform a scroll search, you need to add the scroll parameter to search query and specify how long Elasticsearch should keep the search context viable.

GET mydocs-2019/_search?scroll=40s
{
"size": 5000,
"query": {
"match_all": {}
},
"sort": [
 {
 "_doc": {
  "order": "asc"
   }
  }
 ]
}

This query will return a maximum of  5000 hits and if the scroll is idle for more than 40  seconds, then it will be deleted. The response will return the first page of the results and a scroll id, you can use the scroll id to get additional documents from the scroll. You’re able to keep retrieving the documents until you have all of them.

Notes
  • Changes made to documents after the scroll will not show up in your results.
  • When you are done with the scroll, you can delete it manually using the scroll id.
DELETE _search/scroll/<sroll_id>

About Opster

Opster is redefining Elasticsearch management - pro-actively troubleshooting, optimizing performance, operating on clusters and assisting with all things needed to successfully run ES in production


Click below to learn how to fix common problems related to these concepts
« Back to Index