Logstash: problem for querying elasticsearch

See here:

Seems the documentation on Elasticsearch filter plugin | Logstash Reference [8.11] | Elastic is wrong still. I did what was posted and changed

fields => ["field1", "field2"]

to

fields => [["field1", "field2"]]

and it worked for me as well. Was running into the same error as you with Logstash 2.3.2.