# Add node2 (ES 2.0) to create a cluster with node 1 (ES 1.4.4)

**URL:** <https://discuss.elastic.co/t/add-node2-es-2-0-to-create-a-cluster-with-node-1-es-1-4-4/33702>\
**Category:** Elasticsearch\
**Created:** [November 4, 2015, 5:58am UTC](https://discuss.elastic.co/t/add-node2-es-2-0-to-create-a-cluster-with-node-1-es-1-4-4/33702 "2015-11-04T05:58:33Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![rsjavier](https://avatars.discourse-cdn.com/v4/letter/r/9e8a1a/32.png) [@rsjavier](https://discuss.elastic.co/u/rsjavier)\
**Post date:** [November 4, 2015, 5:58am UTC](https://discuss.elastic.co/t/add-node2-es-2-0-to-create-a-cluster-with-node-1-es-1-4-4/33702/1 "2015-11-04T05:58:33Z")

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Hi,

I try to create a cluster with the old machine and a new one. But I am having problem on unicast discovery.

ES 1.4.4 (old machine)  
cluster.name: elasticsearch  
node.name: "node1"  
node.master: true  
node.data: true  
path.conf: /etc/elasticsearch  
path.data: /var/lib/elasticsearch  
network.host: 10.0.0.35  
discovery.zen.ping.timeout: 10s  
discovery.zen.ping.multicast.enabled: false  
discovery.zen.ping.unicast.hosts : ["10.0.0.35:9300"]

ES 2.0 (new machine)  
cluster.name: elasticsearch  
node.name: "node2"  
node.master: false  
network.host: 10.0.0.27  
discovery.zen.ping.multicast.enabled: false  
discovery.zen.ping.unicast.hosts: ["10.0.0.35:9300"]

The node2 is having problem connecting to node 1.  
$ curl 10.0.0.35:9300  
curl: (52) Empty reply from server

Then the elasticsearch.log in node 1 will show  
[WARN][transport.netty] [node1] Message not fully read (request) for [934] and action [internal:discovery/zen/unicast], resetting

Is there anything I missed? How can I connect node2 ES 2.0 to node1?

Thanks!

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**Author:** ![warkolm](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/warkolm/32/39224_2.png) [@warkolm](https://discuss.elastic.co/u/warkolm)\
**Post date:** [November 4, 2015, 6:11am UTC](https://discuss.elastic.co/t/add-node2-es-2-0-to-create-a-cluster-with-node-1-es-1-4-4/33702/2 "2015-11-04T06:11:49Z")

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You can't!  
The upgrade process from 1.X to 2.X requires a complete cluster restart.

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<div class="post-metadata">

**Author:** ![rsjavier](https://avatars.discourse-cdn.com/v4/letter/r/9e8a1a/32.png) [@rsjavier](https://discuss.elastic.co/u/rsjavier)\
**Post date:** [November 4, 2015, 6:16am UTC](https://discuss.elastic.co/t/add-node2-es-2-0-to-create-a-cluster-with-node-1-es-1-4-4/33702/3 "2015-11-04T06:16:59Z")

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Does this mean I cannot have a cluster with a ES1.4.4 and ES 2.0 together?

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<div class="post-metadata">

**Author:** ![warkolm](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/warkolm/32/39224_2.png) [@warkolm](https://discuss.elastic.co/u/warkolm)\
**Post date:** [November 4, 2015, 6:17am UTC](https://discuss.elastic.co/t/add-node2-es-2-0-to-create-a-cluster-with-node-1-es-1-4-4/33702/4 "2015-11-04T06:17:43Z")

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That is correct.

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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, 11:40pm UTC](https://discuss.elastic.co/t/add-node2-es-2-0-to-create-a-cluster-with-node-1-es-1-4-4/33702/5 "2017-07-05T23:40:44Z")

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