# Total shards per node

**URL:** <https://discuss.elastic.co/t/total-shards-per-node/39887>\
**Category:** Elasticsearch\
**Created:** [January 22, 2016, 2:16pm UTC](https://discuss.elastic.co/t/total-shards-per-node/39887 "2016-01-22T14:16:57Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![manast](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/manast/32/13705_2.png) [@manast](https://discuss.elastic.co/u/manast)\
**Post date:** [January 22, 2016, 2:16pm UTC](https://discuss.elastic.co/t/total-shards-per-node/39887/1 "2016-01-22T14:16:58Z")

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Hello all,

there seems to be an overall consensus as to the number of shards running per node in an Elasticsearch cluster. Different posts (also in this forum) recommend to keep this number small, maybe under a thousand shards per node.

I would be interested to know if a large number of shards is de-facto a problem for a node.  
And if it is why does the configuration setting cluster.routing.allocation.total\_shards\_per\_node default to unbounded?

Thanks,  
Michail

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**Author:** ![magnusbaeck](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/magnusbaeck/32/44943_2.png) [@magnusbaeck](https://discuss.elastic.co/u/magnusbaeck)\
**Post date:** [January 23, 2016, 4:57pm UTC](https://discuss.elastic.co/t/total-shards-per-node/39887/2 "2016-01-23T16:57:14Z")

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> Different posts (also in this forum) recommend to keep this number small, maybe under a thousand shards per node.

A thousand shards sounds like a lot to me. I'd try to limit it a few hundred.

> I would be interested to know if a large number of shards is de-facto a problem for a node.

Yes, because there's a fixed memory overhead for each shard.

> And if it is why does the configuration setting cluster.routing.allocation.total\_shards\_per\_node default to unbounded?

Because there's no obvious optimal value to use as the default?

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**Author:** ![manast](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/manast/32/13705_2.png) [@manast](https://discuss.elastic.co/u/manast)\
**Post date:** [January 23, 2016, 7:14pm UTC](https://discuss.elastic.co/t/total-shards-per-node/39887/3 "2016-01-23T19:14:57Z")

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> [@magnusbaeck](#):
>
> Yes, because there's a fixed memory overhead for each shard.

Is there a way to estimate this overhead if it is fixed?

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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:** [July 5, 2017, 11:22pm UTC](https://discuss.elastic.co/t/total-shards-per-node/39887/4 "2017-07-05T23:22:10Z")

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