# Best way to reindex an ES index which is accepting updated
**URL:** https://discuss.elastic.co/t/best-way-to-reindex-an-es-index-which-is-accepting-updated/138994
**Category:** Elasticsearch
**Created:** [July 7, 2018, 1:16am UTC](https://discuss.elastic.co/t/best-way-to-reindex-an-es-index-which-is-accepting-updated/138994 "2018-07-07T01:16:53Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@sharathr83](https://discuss.elastic.co/u/sharathr83)
#### Post date: [July 7, 2018, 1:16am UTC](https://discuss.elastic.co/t/best-way-to-reindex-an-es-index-which-is-accepting-updated/138994/1 "2018-07-07T01:16:54Z")
I have an ES index which is continuously receiving updates. Apart from inserts and deletes, my index accepts a lot of update operations. Over a period of time, I see a lot of disk IO performance issues because of which I am planning to reindex my cluster every 6 months or so.
I checked out the Reindex API, but this seems to use the current snapshot of the cluster to start copying data. What about the data that is continuously streaming in ? Whats the best way to handle that ?
Also, when you say ReIndex API copies data from one index to another, is it only the data that is copied ? Would disk defragments carry over to the new index ?
---
### Author:  [@warkolm](https://discuss.elastic.co/u/warkolm)
#### Post date: [July 7, 2018, 7:23am UTC](https://discuss.elastic.co/t/best-way-to-reindex-an-es-index-which-is-accepting-updated/138994/2 "2018-07-07T07:23:04Z")
How does your application read from Elasticsearch?
> [@sharathr83](#):
>
> Would disk defragments carry over to the new index ?
Not sure what you mean there.
---
### Author:  [@sharathr83](https://discuss.elastic.co/u/sharathr83)
#### Post date: [July 7, 2018, 9:58am UTC](https://discuss.elastic.co/t/best-way-to-reindex-an-es-index-which-is-accepting-updated/138994/3 "2018-07-07T09:58:42Z")
- We have a python client which uses an index alias to read. So once the reindex completes, I am planning to just switch the alias.
- When you restore a snapshot from elastic, the deleted documents seem to carry over. Which means that my disk IO performance remains the same after a snapshot and restore. Will the same thing happen even if I reindex ?
---
### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [August 4, 2018, 9:58am UTC](https://discuss.elastic.co/t/best-way-to-reindex-an-es-index-which-is-accepting-updated/138994/4 "2018-08-04T09:58:44Z")
This topic was automatically closed 28 days after the last reply. New replies are no longer allowed.