Solution : https://service.sap.com/sap/support/notes/1097047 (SAP Service marketplace login required)
Key words : 
exception stating duplicate key exception, sap easy access menu link, terms sap netweaver mobile 7, multiple extract runs concurrently, list shown        gen_rr_read_extractkeys        gen_extract_message6-, list shown        gen_rr_read_extractkeys        gen_extract_message7-, netweaver mobile admin portal, data orchestration engine admin, data orchestration engine, list shown        gen_rr_read_extract15-
Related Notes : 
       
| 1107348 | Dataobject withMultiple DM-SWCVs &mix of line item filtering | 
| 1106601 | Data not coming to client | 
| 1073391 | NetWeaver Mobile 7.10 Composite Note for SP02 |