PutElasticsearchHttp failed with "failed to parse , document is empty

[#1]

hi

I try to use PutElasticsearchHttp to send json doc to elsaticsearch 6.8 
our nifi server ver 1.15.3
I defined Attribute that contain the json doc with UpdateAtribute processor
UpdateAtribute processor connected to PutElasticsearchHttp
But when PutElasticsearchHttp run we got this error "failed to parse , docuement is empty"
any help is appreciated
Thanks 

[#2]

@Nifi_Al Its hard to guess here without seeing your flow, but i think here are a few ideas to resolve:

Use GenerateFlowFIle with content of the json you want to send to PutElasticsearchHttp
Use AttributesToJson to write attribute to content of flowfile, then send that to PutElasticsearchHttp

To test basic connectivity, i would use the first method, then build a working flow from there.  I always work in small operational samples when trying to figure out how to configure a certain processor.