# Nodes refuse to connect to each other

**URL:** <https://discuss.elastic.co/t/nodes-refuse-to-connect-to-each-other/7874>\
**Category:** Elasticsearch\
**Created:** [May 26, 2012, 12:36pm UTC](https://discuss.elastic.co/t/nodes-refuse-to-connect-to-each-other/7874 "2012-05-26T12:36:33Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Christer](https://avatars.discourse-cdn.com/v4/letter/c/a5b964/32.png) [@Christer](https://discuss.elastic.co/u/Christer)\
**Post date:** [May 26, 2012, 12:36pm UTC](https://discuss.elastic.co/t/nodes-refuse-to-connect-to-each-other/7874/1 "2012-05-26T12:36:33Z")

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I'm playing around with elasticsearch and use two machines to form a  
cluster of two nodes. Recently I added some CPU cores (vmware) to the  
machines to look at performance changes, but as a result of this the nodes  
refuse to connect to each other. I'm not sure that this is a direct result  
of adding CPU cores, but no other changes were made. The nodes does not  
have any indices (no dangling ones either). Both nodes have "network.host"  
set in the configuration as they exist on two different esxi machines and  
we currently don't do multicast.

Could anyone help me debug this issue?

curl [http://es1:9200/\_cluster/health](http://es1:9200/_cluster/health) and curl  
[http://es2:9200/\_cluster/health](http://es2:9200/_cluster/health) gives me the same output:

{  
"cluster\_name": "testCluster",  
"status": "green",  
"timed\_out": false,  
"number\_of\_nodes": 1,  
"number\_of\_data\_nodes": 1,  
"active\_primary\_shards": 0,  
"active\_shards": 0,  
"relocating\_shards": 0,  
"initializing\_shards": 0,  
"unassigned\_shards": 0  
}

As mentioned these machines worked together before the addition of CPU  
cores. Network settings have not been changed

---

<div class="post-metadata">

**Author:** ![kimchy](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/kimchy/32/44952_2.png) [@kimchy](https://discuss.elastic.co/u/kimchy)\
**Post date:** [May 29, 2012, 6:38pm UTC](https://discuss.elastic.co/t/nodes-refuse-to-connect-to-each-other/7874/2 "2012-05-29T18:38:05Z")

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What type of discovery are you using, multicast or unicast?

On Sat, May 26, 2012 at 2:36 PM, Christer [edvartsen.christer@gmail.com](mailto:edvartsen.christer@gmail.com)wrote:

> I'm playing around with elasticsearch and use two machines to form a  
> cluster of two nodes. Recently I added some CPU cores (vmware) to the  
> machines to look at performance changes, but as a result of this the nodes  
> refuse to connect to each other. I'm not sure that this is a direct result  
> of adding CPU cores, but no other changes were made. The nodes does not  
> have any indices (no dangling ones either). Both nodes have "network.host"  
> set in the configuration as they exist on two different esxi machines and  
> we currently don't do multicast.
> 
> Could anyone help me debug this issue?
> 
> curl [http://es1:9200/\_cluster/health](http://es1:9200/_cluster/health) and curl  
> [http://es2:9200/\_cluster/health](http://es2:9200/_cluster/health) gives me the same output:
> 
> {  
> "cluster\_name": "testCluster",  
> "status": "green",  
> "timed\_out": false,  
> "number\_of\_nodes": 1,  
> "number\_of\_data\_nodes": 1,  
> "active\_primary\_shards": 0,  
> "active\_shards": 0,  
> "relocating\_shards": 0,  
> "initializing\_shards": 0,  
> "unassigned\_shards": 0  
> }
> 
> As mentioned these machines worked together before the addition of CPU  
> cores. Network settings have not been changed

---

<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:** [July 6, 2017, 3:26am UTC](https://discuss.elastic.co/t/nodes-refuse-to-connect-to-each-other/7874/3 "2017-07-06T03:26:30Z")

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Closed on July 6, 2017, 3:26am UTC