# Interpolation of discovery.zen.ping.unicast.hosts **URL:** \ **Category:** Elasticsearch\ **Created:** [May 29, 2014, 4:20pm UTC](https://discuss.elastic.co/t/interpolation-of-discovery-zen-ping-unicast-hosts/17811 "2014-05-29T16:20:06Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![mhughes](https://avatars.discourse-cdn.com/v4/letter/m/85e7bf/32.png) [@mhughes](https://discuss.elastic.co/u/mhughes)\ **Post date:** [May 29, 2014, 4:20pm UTC](https://discuss.elastic.co/t/interpolation-of-discovery-zen-ping-unicast-hosts/17811/1 "2014-05-29T16:20:06Z")
I'm trying to set up unicast discovery. I want to pass in the hosts via environment variable and am relying on elasticsearch.yml support of environment variable interpolation. Tried two formats without any luck: First approach (pass in contents of array): export ES\_HOSTS='"one", "two"' discovery.zen.ping.unicast.hosts: [${ES\_HOSTS}] org.elasticsearch.common.settings.SettingsException: Failed to load settings from [file:/etc/elasticsearch/elasticsearch.yml] at org.elasticsearch.common.settings.ImmutableSettings$Builder.loadFromStream(ImmutableSettings.java:920) at org.elasticsearch.common.settings.ImmutableSettings$Builder.loadFromUrl(ImmutableSettings.java:904) at org.elasticsearch.node.internal.InternalSettingsPreparer.prepareSettings(InternalSettingsPreparer.java:77) at org.elasticsearch.bootstrap.Bootstrap.initialSettings(Bootstrap.java:106) at org.elasticsearch.bootstrap.Bootstrap.main(Bootstrap.java:177) at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:32) Caused by: while parsing a flow sequence in 'reader', line 326, column 35: discovery.zen.ping.unicast.hosts: [${ES\_HOSTS}] ^ expected ',' or ']', but got FlowMappingStart in 'reader', line 326, column 37: discovery.zen.ping.unicast.hosts: [${ES\_HOSTS}] Second Approach (pass in full quoted array): export ES\_HOSTS='["one", "two"]' discovery.zen.ping.unicast.hosts: ${ES\_HOSTS} 1. ElasticsearchIllegalArgumentException[Failed to resolve address for [["es1"]]] NumberFormatException[For input string: ""es1""]2) IllegalStateException[This is a proxy used to support circular references involving constructors. The object we're proxying is not constructed yet. Please wait until after injection has completed to use this object.] Any ideas? Is there a doc somewhere that describes how the interpolation occurs? The first error scares me a bit as it seems interpolation happens after some other parsing. -- You received this message because you are subscribed to the Google Groups "elasticsearch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com). To view this discussion on the web visit [https://groups.google.com/d/msgid/elasticsearch/701b9022-b4e5-4422-b376-ab01fba3c233%40googlegroups.com](https://groups.google.com/d/msgid/elasticsearch/701b9022-b4e5-4422-b376-ab01fba3c233%40googlegroups.com). For more options, visit [https://groups.google.com/d/optout](https://groups.google.com/d/optout). ---
**Author:** ![brian\_yoder](https://avatars.discourse-cdn.com/v4/letter/b/f1d935/32.png) [@brian\_yoder](https://discuss.elastic.co/u/brian_yoder)\ **Post date:** [May 29, 2014, 8:09pm UTC](https://discuss.elastic.co/t/interpolation-of-discovery-zen-ping-unicast-hosts/17811/2 "2014-05-29T20:09:01Z")
I believe that the host names must be comma-separated and no quotes or other punctuation should be present. The config within the environment variable or java -D (system properties) is YAML-like, not JSON. No blanks between the names, for example: export ES\_HOSTS=host1,host2,host3 When configuring Unicast, here are the java -D options I use in my own custom Elasticsearch start-up / shutdown / status script: -Des.discovery.zen.ping.multicast.enabled=false -Des.discovery.zen.ping.unicast.hosts=host1,host2,host3 -Des.discovery.zen.minimum\_master\_nodes=2 Brian -- You received this message because you are subscribed to the Google Groups "elasticsearch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com). To view this discussion on the web visit [https://groups.google.com/d/msgid/elasticsearch/d2dad32b-00c7-4c61-b08c-503f5b29c3c6%40googlegroups.com](https://groups.google.com/d/msgid/elasticsearch/d2dad32b-00c7-4c61-b08c-503f5b29c3c6%40googlegroups.com). For more options, visit [https://groups.google.com/d/optout](https://groups.google.com/d/optout). ---
**Author:** ![mhughes](https://avatars.discourse-cdn.com/v4/letter/m/85e7bf/32.png) [@mhughes](https://discuss.elastic.co/u/mhughes)\ **Post date:** [May 30, 2014, 1:25pm UTC](https://discuss.elastic.co/t/interpolation-of-discovery-zen-ping-unicast-hosts/17811/3 "2014-05-30T13:25:05Z")
Yes that works. Docs could really use work there though. The same string in elasticsearch.yml is ["one", "two", "three"], so I assumed I'd need to pass in brackets. On Thursday, May 29, 2014 4:09:02 PM UTC-4, InquiringMind wrote: > I believe that the host names must be comma-separated and no quotes or > other punctuation should be present. The config within the environment > variable or java -D (system properties) is YAML-like, not JSON. No blanks > between the names, for example: > > export ES\_HOSTS=host1,host2,host3 > > When configuring Unicast, here are the java -D options I use in my own > custom Elasticsearch start-up / shutdown / status script: > > -Des.discovery.zen.ping.multicast.enabled=false > -Des.discovery.zen.ping.unicast.hosts=host1,host2,host3 > -Des.discovery.zen.minimum\_master\_nodes=2 > > Brian -- You received this message because you are subscribed to the Google Groups "elasticsearch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com). To view this discussion on the web visit [https://groups.google.com/d/msgid/elasticsearch/9080aad2-f967-4702-a667-b4a30b703fa5%40googlegroups.com](https://groups.google.com/d/msgid/elasticsearch/9080aad2-f967-4702-a667-b4a30b703fa5%40googlegroups.com). For more options, visit [https://groups.google.com/d/optout](https://groups.google.com/d/optout). ---
**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, 1:25am UTC](https://discuss.elastic.co/t/interpolation-of-discovery-zen-ping-unicast-hosts/17811/4 "2017-07-06T01:25:48Z")