Elasticsearch server not accepting connections

Question

I'm trying to access elastic search on my ubuntu server but I'm getting a 502 error in the browser. Nothing in /var/log/elasticsearch/elasticsearch.log is looking useful. The error began after setting xpack.security.enabled: true in /etc/elasticsearch/elasticsearch.yml. After removing that line it still isn't accepting connections.

logs

[2021-08-16T18:25:17,658][INFO ][o.e.i.g.GeoIpDownloader  ] [primary-node] geoip database [GeoLite2-ASN.mmdb] is up to date, updated timestamp
[2021-08-16T18:25:17,804][INFO ][o.e.i.g.DatabaseRegistry ] [primary-node] downloading geoip database [GeoLite2-Country.mmdb] to [/tmp/elasticsearch-4936579661564518666/geoip-databases/_fum6PFWR8GpNoVibLiJrg/GeoLite2-Country.mmdb.tmp.gz]
[2021-08-16T18:25:17,807][INFO ][o.e.i.g.DatabaseRegistry ] [primary-node] downloading geoip database [GeoLite2-ASN.mmdb] to [/tmp/elasticsearch-4936579661564518666/geoip-databases/_fum6PFWR8GpNoVibLiJrg/GeoLite2-ASN.mmdb.tmp.gz]
[2021-08-16T18:25:17,812][INFO ][o.e.i.g.DatabaseRegistry ] [primary-node] downloading geoip database [GeoLite2-City.mmdb] to [/tmp/elasticsearch-4936579661564518666/geoip-databases/_fum6PFWR8GpNoVibLiJrg/GeoLite2-City.mmdb.tmp.gz]
[2021-08-16T18:25:18,156][INFO ][o.e.i.g.GeoIpDownloader  ] [primary-node] geoip database [GeoLite2-City.mmdb] is up to date, updated timestamp
[2021-08-16T18:25:18,254][INFO ][o.e.i.g.DatabaseRegistry ] [primary-node] database file changed [/tmp/elasticsearch-4936579661564518666/geoip-databases/_fum6PFWR8GpNoVibLiJrg/GeoLite2-ASN.mmdb], reload database...
[2021-08-16T18:25:18,257][INFO ][o.e.i.g.DatabaseRegistry ] [primary-node] database file changed [/tmp/elasticsearch-4936579661564518666/geoip-databases/_fum6PFWR8GpNoVibLiJrg/GeoLite2-Country.mmdb], reload database...
[2021-08-16T18:25:18,709][INFO ][o.e.c.r.a.AllocationService] [primary-node] Cluster health status changed from [RED] to [YELLOW] (reason: [shards started [[legiscan_model_bills_production_20210816163135035][0]]]).
[2021-08-16T18:25:19,030][INFO ][o.e.i.g.GeoIpDownloader  ] [primary-node] geoip database [GeoLite2-Country.mmdb] is up to date, updated timestamp
[2021-08-16T18:25:19,816][INFO ][o.e.i.g.DatabaseRegistry ] [primary-node] database file changed [/tmp/elasticsearch-4936579661564518666/geoip-databases/_fum6PFWR8GpNoVibLiJrg/GeoLite2-City.mmdb], reload database...

Answer 1

From Elasticsearc official guide

Enabling the Elasticsearch security features enables basic authentication so that you can run a local cluster with username and password authentication.

Since you've enabled xpack.security you have to create a elasticsearch password and use this pass to connect to it: https://www.elastic.co/guide/en/elasticsearch/reference/current/security-minimal-setup.html#security-create-builtin-users

Create a passowrd with steps in the link above and than try to connect again using username "elastic" and the created password

Answer 2

Check the upper part of your start up log file. Probably, there are other errors printed. In my case too, the last line was about trying to load geoip-databases. Actual root cause was low disk space on the path where data directory was hosted.ElasticSearch version: 7.14.0