i tried to user PutElasticsearchHttp Nifi processor but encounter error like attached picture (I use Nifi 1.2 and ElasticSearch 6).
The PutElasticsearch processor supports Elasticsearch 2.x and the PutElasticsearch5 [processor supports Elasticsearch 5.x.
There is no PutElasticsearch 6.x processor available in NiFi.
There is a putElasticsearchHttp processor that uses the Elasticsearch rest api end point which is a little more dynamic in it support of various ES end points versions. I suggest giving it a try.
I would start by looking in the nifi-app.log for the above ERROR and see if a stack trace follows it. The stack trace will hopefully share more light on the exact issue encountered since the above bulletin is not very helpful.
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