Fluentd - Could not communicate to Elasticsearch, resetting connection and trying again. getaddrinfo: Name or service not known (SocketError)

Question

In an EFK setup, the fluentd suddenly stopped sending to elasticsearch with the following errors in the logs:

2020-09-28 18:48:55 +0000 [warn]: #0 Could not communicate to Elasticsearch, resetting connection and trying again. getaddrinfo: Name or service not known (SocketError)
2020-09-28 18:48:55 +0000 [warn]: #0 Remaining retry: 6. Retry to communicate after 512 second(s).

The elasticsearch components are up and running, and I can curl and access elasticsearch from inside the fluentd pod. There is no error message in the logs of the elasticsearch.

Restarting the fluentd pod or elasticsearch components did not help.

Answer 1

The issue was in one of the configurations that was uploaded to fluentd. The elasticsearch host was set to a wrong value in that configuration. After fixing that configuration, the issue waa resolved.