A user ran into an issue which can be roughly described as:
"We need to provide a scheme, because otherwise http is used even if secure = true"
So a config like this:
will try http. If https://myhost:9201 is used, it will work.
Note that there is a check which checks the reverse (so if secure is false, but https is used), but not the other way round.
Cursory inspection of https://github.com/couchbase/couchbase-elasticsearch-connector/blob/4.2.0/src/main/java/com/couchbase/connector/config/ConfigHelper.java#L70 suggests that HttpHost will default to HTTP scheme if not explicitly provided, but it should use https if secure = true .. and/or some sanity check?