the timestamp field can be picky. I would debug this in two phases: first set_field a test field and check that it works. If it works, the problem can be the date format specified in elasticsearch for the timestamp field. You might need to loosen it to accept the date in the format the parse_date function gives. (see field mappings in Elasticsearch: https://www.elastic.co/guide/en/elasticsearch/reference/5.4/date.html) I remember that I had a similar problem at some point.