# Question about unicast discovery that finds only 2 out of 3 active nodes
**URL:** https://discuss.elastic.co/t/question-about-unicast-discovery-that-finds-only-2-out-of-3-active-nodes/11736
**Category:** Elasticsearch
**Created:** [April 29, 2013, 7:02pm UTC](https://discuss.elastic.co/t/question-about-unicast-discovery-that-finds-only-2-out-of-3-active-nodes/11736 "2013-04-29T19:02:36Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@brian\_yoder](https://discuss.elastic.co/u/brian_yoder)
#### Post date: [April 29, 2013, 7:02pm UTC](https://discuss.elastic.co/t/question-about-unicast-discovery-that-finds-only-2-out-of-3-active-nodes/11736/1 "2013-04-29T19:02:36Z")
I am trying to set up a 3-node unicast-discovery cluster named
test-server-3amigos. But all I can get is 2 nodes that like each other and
a third node that appears to be a rejected lonely outcast.
I would have thought that the -D options would have overridden the cluster
to recognize all three nodes as part of the cluster.
Here are the command-line java arguments when elasticsearch is started.
Note that I set the node names to the host names for easier investigation!
ElasticSearch pid is 23436
/usr/bin/pargs
23436: /bin/java -server -Xms256m -Xmx1g -Xss256k -Djava.awt.headless=true
-XX:+UsePar
argv[0]: /bin/java
argv[1]: -server
argv[2]: -Xms256m
argv[3]: -Xmx1g
argv[4]: -Xss256k
argv[5]: -Djava.awt.headless=true
argv[6]: -XX:+UseParNewGC
argv[7]: -XX:+UseConcMarkSweepGC
argv[8]: -XX:CMSInitiatingOccupancyFraction=75
argv[9]: -XX:+UseCMSInitiatingOccupancyOnly
argv[10]: -XX:+HeapDumpOnOutOfMemoryError
argv[11]: -Delasticsearch
argv[12]: -Des.pidfile=/tmp/es-test-server-3amigos.pid
argv[13]:
-Des.path.home=/opt/test-server/versions/2781.116/elasticsearch-0.20.4
argv[14]: -cp
argv[15]:
/opt/test-server/current/elasticsearch-0.20.4/lib:/opt/test-server/versions/2781.116/elasticsearch-0.20.4/lib/elasticsearch-0.20.4.jar:/opt/test-server/versions/2781.116/elasticsearch-0.20.4/lib/_:/opt/test-server/versions/2781.116/elasticsearch-0.20.4/lib/sigar/_
argv[16]: -Des.node.name=testdev12
argv[17]: -Des.path.conf=/opt/test-server/current/config
argv[18]: _-Ddiscovery.zen.ping.multicast.enabled=false_
argv[19]: _-Ddiscovery.zen.ping.unicast.hosts=testdev12,testdev29,testdev33_
argv[20]: -Ddiscovery.zen.minimum\_master\_nodes=2
argv[21]: org.elasticsearch.bootstrap.ElasticSearch
And my elasticsearch.yml file is unchanged. Don't the command-line settings
above override the discovery? They seem to be ignored.
################################## Discovery
##################################
# Discovery infrastructure ensures nodes can be found within a cluster
# and master node is elected. Multicast discovery is the default.
# Set to ensure a node sees N other master eligible nodes to be considered
# operational within the cluster. Set this option to a higher value (2-4)
# for large clusters (\>3 nodes):
#
# discovery.zen.minimum\_master\_nodes: 1
# Set the time to wait for ping responses from other nodes when discovering.
# Set this option to a higher value on a slow or congested network
# to minimize discovery failures:
#
# discovery.zen.ping.timeout: 3s
# See [http://elasticsearch.org/guide/reference/modules/discovery/zen.html](http://elasticsearch.org/guide/reference/modules/discovery/zen.html)
# for more information.
# Unicast discovery allows to explicitly control which nodes will be used
# to discover the cluster. It can be used when multicast is not present,
# or to restrict the cluster communication-wise.
#
# 1. Disable multicast discovery (enabled by default):
#
# discovery.zen.ping.multicast.enabled: false
#
# 2. Configure an initial list of master nodes in the cluster
# to perform discovery when new nodes (master or data) are started:
#
# discovery.zen.ping.unicast.hosts: ["host1", "host2:port",
"host3[portX-portY]"]
Nodes 12 and 29 see each other but not node 33:
$ curl '[http://testdev12:9200/\_cluster/state?pretty=true](http://testdev12:9200/_cluster/state?pretty=true)'
{
"cluster\_name" : "test-lidb-3amigos",
"master\_node" : "o5jRwGzxSqGYqgcl2aY-oA",
"blocks" : { },
"nodes" : {
"o5jRwGzxSqGYqgcl2aY-oA" : {
"name" : "testdev12",
"transport\_address" : "inet[/192.168.200.222:9300]",
"attributes" : {
"max\_local\_storage\_nodes" : "1"
}
},
"o2gtWBcqQB2-Tx22WwH2vg" : {
"name" : "testdev29",
"transport\_address" : "inet[/192.168.200.241:9300]",
"attributes" : {
"max\_local\_storage\_nodes" : "1"
}
}
},
"metadata" : {
"templates" : { },
"indices" : { }
},
"routing\_table" : {
"indices" : { }
},
"routing\_nodes" : {
"unassigned" : [],
"nodes" : {
"o5jRwGzxSqGYqgcl2aY-oA" : [],
"o2gtWBcqQB2-Tx22WwH2vg" : []
}
},
"allocations" : []
}
While node 33 is all by itself, but it shows up in ElasticSearch Head in a
green status:
$ curl '[http://testdev33:9200/\_cluster/state?pretty=true](http://testdev33:9200/_cluster/state?pretty=true)'
{
"cluster\_name" : "test-lidb-3amigos",
"master\_node" : "cim4vJBRS3ajkCRD8FGIug",
"blocks" : { },
"nodes" : {
"cim4vJBRS3ajkCRD8FGIug" : {
"name" : "testdev33",
"transport\_address" : "inet[/192.168.200.133:9300]",
"attributes" : {
"max\_local\_storage\_nodes" : "1"
}
}
},
"metadata" : {
"templates" : { },
"indices" : { }
},
"routing\_table" : {
"indices" : { }
},
"routing\_nodes" : {
"unassigned" : [],
"nodes" : {
"cim4vJBRS3ajkCRD8FGIug" : []
}
},
"allocations" : []
}
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### Author:  [@dadoonet](https://discuss.elastic.co/u/dadoonet)
#### Post date: [April 29, 2013, 7:33pm UTC](https://discuss.elastic.co/t/question-about-unicast-discovery-that-finds-only-2-out-of-3-active-nodes/11736/2 "2013-04-29T19:33:36Z")
Prefix it with "es."
So it should be:
argv[18]: -Des.discovery.zen.ping.multicast.enabled=false
argv[19]: -Des.discovery.zen.ping.unicast.hosts=testdev12,testdev29,testdev33
argv[20]: -Des.discovery.zen.minimum\_master\_nodes=2
My 2 cents
--
David ๐
Twitter : @dadoonet / @elasticsearchfr / @scrutmydocs
Le 29 avr. 2013 ร 21:02, InquiringMind [brian.from.fl@gmail.com](mailto:brian.from.fl@gmail.com) a รฉcrit :
I am trying to set up a 3-node unicast-discovery cluster named test-server-3amigos. But all I can get is 2 nodes that like each other and a third node that appears to be a rejected lonely outcast.
I would have thought that the -D options would have overridden the cluster to recognize all three nodes as part of the cluster.
Here are the command-line java arguments when elasticsearch is started. Note that I set the node names to the host names for easier investigation!
ElasticSearch pid is 23436
/usr/bin/pargs
23436: /bin/java -server -Xms256m -Xmx1g -Xss256k -Djava.awt.headless=true -XX:+UsePar
argv[0]: /bin/java
argv[1]: -server
argv[2]: -Xms256m
argv[3]: -Xmx1g
argv[4]: -Xss256k
argv[5]: -Djava.awt.headless=true
argv[6]: -XX:+UseParNewGC
argv[7]: -XX:+UseConcMarkSweepGC
argv[8]: -XX:CMSInitiatingOccupancyFraction=75
argv[9]: -XX:+UseCMSInitiatingOccupancyOnly
argv[10]: -XX:+HeapDumpOnOutOfMemoryError
argv[11]: -Delasticsearch
argv[12]: -Des.pidfile=/tmp/es-test-server-3amigos.pid
argv[13]: -Des.path.home=/opt/test-server/versions/2781.116/elasticsearch-0.20.4
argv[14]: -cp
argv[15]: /opt/test-server/current/elasticsearch-0.20.4/lib:/opt/test-server/versions/2781.116/elasticsearch-0.20.4/lib/elasticsearch-0.20.4.jar:/opt/test-server/versions/2781.116/elasticsearch-0.20.4/lib/_:/opt/test-server/versions/2781.116/elasticsearch-0.20.4/lib/sigar/_
argv[16]: -Des.node.name=testdev12
argv[17]: -Des.path.conf=/opt/test-server/current/config
argv[18]: -Ddiscovery.zen.ping.multicast.enabled=false
argv[19]: -Ddiscovery.zen.ping.unicast.hosts=testdev12,testdev29,testdev33
argv[20]: -Ddiscovery.zen.minimum\_master\_nodes=2
argv[21]: org.elasticsearch.bootstrap.ElasticSearch
And my elasticsearch.yml file is unchanged. Don't the command-line settings above override the discovery? They seem to be ignored.
################################## Discovery ##################################
# Discovery infrastructure ensures nodes can be found within a cluster
# and master node is elected. Multicast discovery is the default.
# Set to ensure a node sees N other master eligible nodes to be considered
# operational within the cluster. Set this option to a higher value (2-4)
# for large clusters (\>3 nodes):
#
# discovery.zen.minimum\_master\_nodes: 1
# Set the time to wait for ping responses from other nodes when discovering.
# Set this option to a higher value on a slow or congested network
# to minimize discovery failures:
#
# discovery.zen.ping.timeout: 3s
# See [http://elasticsearch.org/guide/reference/modules/discovery/zen.html](http://elasticsearch.org/guide/reference/modules/discovery/zen.html)
# for more information.
# Unicast discovery allows to explicitly control which nodes will be used
# to discover the cluster. It can be used when multicast is not present,
# or to restrict the cluster communication-wise.
#
# 1. Disable multicast discovery (enabled by default):
#
# discovery.zen.ping.multicast.enabled: false
#
# 2. Configure an initial list of master nodes in the cluster
# to perform discovery when new nodes (master or data) are started:
#
# discovery.zen.ping.unicast.hosts: ["host1", "host2:port", "host3[portX-portY]"]
Nodes 12 and 29 see each other but not node 33:
$ curl '[http://testdev12:9200/\_cluster/state?pretty=true](http://testdev12:9200/_cluster/state?pretty=true)'
{
"cluster\_name" : "test-lidb-3amigos",
"master\_node" : "o5jRwGzxSqGYqgcl2aY-oA",
"blocks" : { },
"nodes" : {
"o5jRwGzxSqGYqgcl2aY-oA" : {
"name" : "testdev12",
"transport\_address" : "inet[/192.168.200.222:9300]",
"attributes" : {
"max\_local\_storage\_nodes" : "1"
}
},
"o2gtWBcqQB2-Tx22WwH2vg" : {
"name" : "testdev29",
"transport\_address" : "inet[/192.168.200.241:9300]",
"attributes" : {
"max\_local\_storage\_nodes" : "1"
}
}
},
"metadata" : {
"templates" : { },
"indices" : { }
},
"routing\_table" : {
"indices" : { }
},
"routing\_nodes" : {
"unassigned" : [],
"nodes" : {
"o5jRwGzxSqGYqgcl2aY-oA" : [],
"o2gtWBcqQB2-Tx22WwH2vg" : []
}
},
"allocations" : []
}
While node 33 is all by itself, but it shows up in ElasticSearch Head in a green status:
## $ curl '[http://testdev33:9200/\_cluster/state?pretty=true](http://testdev33:9200/_cluster/state?pretty=true)' { "cluster\_name" : "test-lidb-3amigos", "master\_node" : "cim4vJBRS3ajkCRD8FGIug", "blocks" : { }, "nodes" : { "cim4vJBRS3ajkCRD8FGIug" : { "name" : "testdev33", "transport\_address" : "inet[/192.168.200.133:9300]", "attributes" : { "max\_local\_storage\_nodes" : "1" } } }, "metadata" : { "templates" : { }, "indices" : { } }, "routing\_table" : { "indices" : { } }, "routing\_nodes" : { "unassigned" : [], "nodes" : { "cim4vJBRS3ajkCRD8FGIug" : [] } }, "allocations" : [] }
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### Author:  [@brian\_yoder](https://discuss.elastic.co/u/brian_yoder)
#### Post date: [April 29, 2013, 8:01pm UTC](https://discuss.elastic.co/t/question-about-unicast-discovery-that-finds-only-2-out-of-3-active-nodes/11736/3 "2013-04-29T20:01:42Z")
David,
Thank you very much. Early indications show that's exactly what was
missing. Your 2 cents apparently has a very favorable exchange rate! ๐
On Monday, April 29, 2013 3:33:36 PM UTC-4, David Pilato wrote:
> Prefix it with "es."
>
> So it should be:
> argv[18]: _-Des.discovery.zen.ping.multicast.enabled=false_
> argv[19]: \*
> -Des.discovery.zen.ping.unicast.hosts=testdev12,testdev29,testdev33\*
> argv[20]: -Des.discovery.zen.minimum\_master\_nodes=2
>
> My 2 cents
>
> --
> David ๐
> Twitter : @dadoonet / @elasticsearchfr / @scrutmydocs
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### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [July 6, 2017, 2:39am UTC](https://discuss.elastic.co/t/question-about-unicast-discovery-that-finds-only-2-out-of-3-active-nodes/11736/4 "2017-07-06T02:39:09Z")