# One Master Node removes and adds cluster nodes on regular base

**URL:** https://discuss.elastic.co/t/one-master-node-removes-and-adds-cluster-nodes-on-regular-base/156700
**Category:** Elasticsearch
**Created:** [November 14, 2018, 3:02pm UTC](https://discuss.elastic.co/t/one-master-node-removes-and-adds-cluster-nodes-on-regular-base/156700 "2018-11-14T15:02:07Z")
**Posts on this page:** 1
**Showing post:** 3

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### Author: ![Thomas\_Tomski](https://avatars.discourse-cdn.com/v4/letter/t/5fc32e/32.png) [@Thomas\_Tomski](https://discuss.elastic.co/u/Thomas_Tomski)
#### Post date: [November 26, 2018, 9:39am UTC](https://discuss.elastic.co/t/one-master-node-removes-and-adds-cluster-nodes-on-regular-base/156700/3 "2018-11-26T09:39:52Z")

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Hello,

The problem was the same as here:

> [@Node disconnects every hour](https://discuss.elastic.co/t/node-disconnects-every-hour/37162/16):
>
> ES 2.1.0 When you say it removed and re-adds, does it mean it drops the node and re-adds the node, making many shards go unassigned and have to be assigned again? This is exactly what is happening. I see cluster goes into yellow every hour and many shards become unassigned.

It was solved by modifying the sysctl parameters:

```
 # Reduce keep alive values to increase frequency of keep alive packets sent across network in order to prevent ElasticSearch nodes losing connection between each other
net.ipv4.tcp_keepalive_time = 600
net.ipv4.tcp_keepalive_intvl = 60
net.ipv4.tcp_keepalive_probes = 20

```

Cheers!

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