ES Query to sort data on Timestamp

I have a very basic requirement. I am indexing the records based on timestamp.

E.g

{ "temperature": [value], "deviceID":[value] , Timestamp: [ts]}
{ "temperature": [value], "deviceID":[value],Timestamp: [ts] }
{ "temperature": [value], "deviceID":[value],Timestamp: [ts] }

These record/events are added every 1 minute. I would like to query ES and find out the last 10 records ordered by timestamp for a particular deviceID. So, the first record should be t-10, then t-9, then t-8, ...

{

"sort":[  {"Timestamp": { "order" : "asc" }} ],
  "query": {
    "bool": {
      "must": {
        "match": {
          "deviceID": 1
        }
      },
      "filter": {
        "range": {
          "Timestamp": {
            "gte": "now-10m"
          }
        }
      }
    }
},
"_source" : [ "temperature","deviceID","Timestamp"]
}

I realized that every time it gives different results ... ( though it is sorted based on Timestamp ). It is not giving any definitive result if i run it multiple time.

Am i missing something obvious ?

Please advise as i am not an expert in ES query DSL.Preformatted text

Hey,

can you be more specific in what way the results are diverting? Do you have results with the same timestamp and thus the sorting is not stable?

--Alex