# What is the maximum indexes I can have in one ES cluster? **URL:** \ **Category:** Elasticsearch\ **Created:** [February 10, 2020, 12:41am UTC](https://discuss.elastic.co/t/what-is-the-maximum-indexes-i-can-have-in-one-es-cluster/218492 "2020-02-10T00:41:21Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![yuecong](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/yuecong/32/49061_2.png) [@yuecong](https://discuss.elastic.co/u/yuecong)\ **Post date:** [February 10, 2020, 12:41am UTC](https://discuss.elastic.co/t/what-is-the-maximum-indexes-i-can-have-in-one-es-cluster/218492/1 "2020-02-10T00:41:21Z")
I understand one ES shard is one Lucien index and it will consume some amount of CPU/ memory. Is there some limitation on how many ES indexes I can have for one ES cluster? e.g. if I have thousands of indexes, but most of them the indexes are not active for reading/ writing, does those ES indexes consume CPU and memory as well? Is there some fixed amount of CPU/ memory required for one ES index? ---
**Author:** ![rameshkr1994](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/rameshkr1994/32/59029_2.png) [@rameshkr1994](https://discuss.elastic.co/u/rameshkr1994)\ **Post date:** [February 10, 2020, 11:38am UTC](https://discuss.elastic.co/t/what-is-the-maximum-indexes-i-can-have-in-one-es-cluster/218492/2 "2020-02-10T11:38:23Z")
Hi @yuecong. I think you need to check here- [\> Blockquote](https://www.elastic.co/blog/found-sizing-elasticsearch) Thanks HadoopHelp ---
**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:** [February 10, 2020, 6:22pm UTC](https://discuss.elastic.co/t/what-is-the-maximum-indexes-i-can-have-in-one-es-cluster/218492/3 "2020-02-10T18:22:19Z")
All open indices and shards take up some amount of resources. There is also information about indices, shards and mappings stored in the cluster state, and once this gets large it can cause cluster state updates to be slow which can hamper performance and lead to stability problems. The number of indices and shards therefore matter, and it may not be heap exhaustion that causes problems first. Elasticsearch does not scale well with very large number of small shards, and [it is possible to crash a cluster by just creating indices and shards even if you do not put any data in it](https://www.elastic.co/blog/found-crash-elasticsearch). ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [March 9, 2020, 6:22pm UTC](https://discuss.elastic.co/t/what-is-the-maximum-indexes-i-can-have-in-one-es-cluster/218492/4 "2020-03-09T18:22:32Z")
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