@dadoonet thanks for the quick response... we used bulk API as below
{"create":{"_index":"sleepdata","_type":"n1-njsmnfee1f3oh72zg","_id":1447186076}}
{"start":"2015-11-10T20:07:56.000Z","end":"2015-11-10T22:58:56.000Z","startIndex":585,"endIndex":761,"info":{"graph":[0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0],"restlessCount":3,"wakeupCount":0,"averageDiff":2.0760233918128654,"totalTime":171,"totalBadTime":9,"deepMinute":6},"oldstart":"2015-11-10T20:02:56.000Z","oldEnd":"2015-11-10T22:58:56.000Z","id":1447186076,"startUnix":1447186076,"endUnix":1447196336}
We are certain that the id is not been created before.