Read this and specifically the "Also be patient" part.
It's fine to answer on your own thread after 2 or 3 days (not including weekends) if you don't have an answer.
what is the difference between the doc.count from '_cat/indices' and 'cscfcounter/_search?routing=1'
The later counts documents that are available for search from one single shard (the shard which correspond to routing key = 1).
IIRC the former counts the documents that have been indexed (including documents that have been removed may be)
To add in golang where can i get the API list? and i understand that i have missed to 'routing' the in delete_by_query. So is it possible to add in golang syntax.?
I don't know. I don't know the go client.
In the first place, why are you using routing?