# Automatic replications factor

**URL:** <https://discuss.elastic.co/t/automatic-replications-factor/259996>\
**Category:** Elasticsearch\
**Created:** [January 1, 2021, 2:05pm UTC](https://discuss.elastic.co/t/automatic-replications-factor/259996 "2021-01-01T14:05:35Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Itay\_Bittan](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/itay_bittan/32/23527_2.png) [@Itay\_Bittan](https://discuss.elastic.co/u/Itay_Bittan)\
**Post date:** [January 1, 2021, 2:05pm UTC](https://discuss.elastic.co/t/automatic-replications-factor/259996/1 "2021-01-01T14:05:35Z")

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Hi,

I wonder if there is a feature for dynamically changing the replication\_factor of each index.

We have an Elasticseach cluster with hundreds of indices as part of our recommendations engine. Each index represents a different customer (encapsulation and privacy reasons).  
Some of the indices (aka customers) are queried 300 times in a second while others can be queried once in a minute.  
We are happy users of the "Adaptive Replica Selection" that help us to improve performance for those "heavy" (in term of search per second) indices.  
Today we are manually set the `replication_factor` per each index: "heavy" indices get high `replication_factor` (5-6) while lighter get 1-2 - but that's not a scalable solution and required manual intervention.  
As we grow fast, the idea is the keep the optimal number of shards and stop adding data nodes.

I wonder if such a feature exists? is it is on the roadmap, or is it something I can develop as a plugin?  
The search rate can be retrieved from the index status and can assist to decide whether this index needs more or fewer replicas.

Thoughts?  
Thanks,  
Itay

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<div class="post-metadata">

**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\
**Post date:** [January 29, 2021, 2:05pm UTC](https://discuss.elastic.co/t/automatic-replications-factor/259996/2 "2021-01-29T14:05:35Z")

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