mongodb/mongo-hadoop — comment on commit a9e889b19bff52c126316f0354e09c0b13481f76
File: core/src/main/java/com/mongodb/hadoop/output/MongoRecordWriter.java line 41
By josephks:

This is where you are writing from Hadoop to Mongo. You want to send Strings to Mongo, not Texts, which will fail the BSON conversion.