# Shard reallocation when nodes are down
**URL:** https://discuss.elastic.co/t/shard-reallocation-when-nodes-are-down/85023
**Category:** Elasticsearch
**Created:** [May 9, 2017, 7:14am UTC](https://discuss.elastic.co/t/shard-reallocation-when-nodes-are-down/85023 "2017-05-09T07:14:35Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@sharongur](https://discuss.elastic.co/u/sharongur)
#### Post date: [May 9, 2017, 7:14am UTC](https://discuss.elastic.co/t/shard-reallocation-when-nodes-are-down/85023/1 "2017-05-09T07:14:35Z")
Hi all,
Everyone keeps stating how Elasticsearch is smart and knows to reallocate when a node is down.
But i cant seem to find the conditions for which Elastic determine **when** the node is down.
If i have a connection hiccup, will elastic start reallocating through my network? and when the node returns, elastic might see it as a "new" node and allocate it new data?
Is there a way to change those conditions?
Can I decide that if a certain machine is down, dont reallocate and state the cluster health as red?
Thanks in advance!
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### Author:  [@jpountz](https://discuss.elastic.co/u/jpountz)
#### Post date: [May 9, 2017, 8:31am UTC](https://discuss.elastic.co/t/shard-reallocation-when-nodes-are-down/85023/2 "2017-05-09T08:31:16Z")
A node is considered down when it does not respond to pings anymore: [https://www.elastic.co/guide/en/elasticsearch/reference/5.4/modules-discovery-zen.html#fault-detection](https://www.elastic.co/guide/en/elasticsearch/reference/5.4/modules-discovery-zen.html#fault-detection).
You might also want to read about delayed shard allocation: [https://www.elastic.co/guide/en/elasticsearch/reference/current/delayed-allocation.html](https://www.elastic.co/guide/en/elasticsearch/reference/current/delayed-allocation.html).
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### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [June 6, 2017, 8:32am UTC](https://discuss.elastic.co/t/shard-reallocation-when-nodes-are-down/85023/3 "2017-06-06T08:32:06Z")
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