Im running   a kettle loader which extracts data from a database on the same mysql instance as my opnenvpms database. (uses 2 different connection lines) I had "USE RESULT STREAMING CURSOR" checked for both connections

Unfortunately MYSQL has concurrency issues. 

Hence I apparently need to turn of the streaming (not quite sure in one or both) and hope to heck the machine I am using to process the data can cope with the size of the data. 

Be aware if that it may be advisable to use seperate mysql instances to load data FROM and TO.  rather than just seperate data bases's and if you are using 2 connections to the one instance...untick the result streaming cursor option in the database parameters of KETTLE.