# Indexing speed single vs multiple clusters

**URL:** <https://discuss.elastic.co/t/indexing-speed-single-vs-multiple-clusters/333910>\
**Category:** Elasticsearch\
**Created:** [May 20, 2023, 2:20pm UTC](https://discuss.elastic.co/t/indexing-speed-single-vs-multiple-clusters/333910 "2023-05-20T14:20:17Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![sliu](https://avatars.discourse-cdn.com/v4/letter/s/a9a28c/32.png) [@sliu](https://discuss.elastic.co/u/sliu)\
**Post date:** [May 20, 2023, 2:20pm UTC](https://discuss.elastic.co/t/indexing-speed-single-vs-multiple-clusters/333910/1 "2023-05-20T14:20:17Z")

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Here's my simplified use case: three indexes, each has 5 billion documents. No need to hit multiple indexes in search. The length of time to index the data is in concern here. With three server nodes, I can have:  
(1) single Elasticsearch cluster with 3 nodes. Indexing in three threads  
(2) three Elasticsearch clusters, each has its own server node.  
My experiment shows (1) is a lot slower than (2) to index all data, about 50% slower. I hope to hear others share their experience on this -- do you see similar performance in (1), or maybe something (configuration) I didn't get right?

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**Author:** ![Christian\_Dahlqvist](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/christian_dahlqvist/32/4617_2.png) [@Christian\_Dahlqvist](https://discuss.elastic.co/u/Christian_Dahlqvist)\
**Post date:** [May 20, 2023, 6:22pm UTC](https://discuss.elastic.co/t/indexing-speed-single-vs-multiple-clusters/333910/2 "2023-05-20T18:22:41Z")

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> [@sliu](#):
>
> (1) single Elasticsearch cluster with 3 nodes. Indexing in three threads  
> (2) three Elasticsearch clusters, each has its own server node.

Is the hardware the same here between the 3 scenarios? Is the only difference that you in one case have 3 clustered nodes and in the other you instead have 3 single-node clusters?

What type of hardware are you deploying on?

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**Author:** ![sliu](https://avatars.discourse-cdn.com/v4/letter/s/a9a28c/32.png) [@sliu](https://discuss.elastic.co/u/sliu)\
**Post date:** [May 20, 2023, 8:08pm UTC](https://discuss.elastic.co/t/indexing-speed-single-vs-multiple-clusters/333910/3 "2023-05-20T20:08:03Z")

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yes the hardware is all the same, ec2 server (16 vcpu, 128 GB). Thanks

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**Author:** ![Christian\_Dahlqvist](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/christian_dahlqvist/32/4617_2.png) [@Christian\_Dahlqvist](https://discuss.elastic.co/u/Christian_Dahlqvist)\
**Post date:** [May 21, 2023, 4:22am UTC](https://discuss.elastic.co/t/indexing-speed-single-vs-multiple-clusters/333910/4 "2023-05-21T04:22:14Z")

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Are you using one instance per host or do you host all 3 nodes on a single host? Which instance type are you using?

> [@sliu](#):
>
> Indexing in three threads

This sounds very low. How are you indexing into Elasticsearch? What bulk size are you using? What is the average size of your documents?

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**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\
**Post date:** [June 18, 2023, 4:22am UTC](https://discuss.elastic.co/t/indexing-speed-single-vs-multiple-clusters/333910/5 "2023-06-18T04:22:16Z")

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