Elasticsearch 5.5.0 is not on mavenCentral?

Elastic Stack Elasticsearch
1

See http://mvnrepository.com/artifact/org.elasticsearch/elasticsearch

2

It's there

http://search.maven.org/#artifactdetails|org.elasticsearch|elasticsearch|5.5.0|jar

http://repo1.maven.org/maven2/org/elasticsearch/elasticsearch/5.5.0/

3

That is not Maven Central, and it takes time for it to sync with Maven Central (and is outside of our control). Also, it's there now. In general, I would suggest using the actual Sonatype repository at Maven Central, that's where we publish and it is the source of truth.