this was the right lead, thanks Alex
> Am 08.02.2017 um 22:20 schrieb Alexandre Rafalovitch :
>
> /update/json expects Solr JSON update format.
> /update is an auto-route that should be equivalent to /update/json
> with the right content type/extension.
>
> /update/json/docs expects random JSON
/update/json expects Solr JSON update format.
/update is an auto-route that should be equivalent to /update/json
with the right content type/extension.
/update/json/docs expects random JSON and tries to extract fields for
indexing from it.
https://cwiki.apache.org/confluence/display/solr/Transform