: How do I achieve, add if not there, fail if duplicate is found. I though
You can use the optimistic concurrency features to do this, by including a _version_=-1 field value in the document. this will instruct solr that the update should only be processed if the document does not already exist... https://cwiki.apache.org/confluence/display/solr/Updating+Parts+of+Documents -Hoss http://www.lucidworks.com/
