dataTable custom loading contents - elasticsearch

Question

I post a query to elasticsearch with http request via datatable. and get json data as response. I need to bind this data in jquery datatable.
var query="";
var tableObjects = $("#logTable").DataTable({
"bProcessing": false,
"bServerSide": true,
"sAjaxSource": "http://localhost:9200/webproxylog/_search?source=",
"aoColumns": [
{"mDataProp": "clientname" ,"sortable": false },
{"mDataProp": "clientip"},
{"mDataProp": "url"},
{"mDataProp": "category"},
{"mDataProp": "respsize","sortable": true},
{"mDataProp": "loggingdate"},
{"mDataProp": "reqmethod"},
{"mDataProp": "resultcode"},
{"mDataProp": "duration"}
],
"fnServerData": function (sSource, aoData, fnCallback){
var sEcho=aoData[0].value
query = '{"from":"'+aoData[3].value+'","size":"'+aoData[4].value+'","query":{"match_all":{}},"sort": [{"loggingdate": {"order": "desc"}}]}';
$.ajax({
"dataType": "json",
"contentType": "application/json; charset=utf-8",
"type": "GET",
"url": sSource,
"data": query,
"success": function(response){
debugger
var result_ = new Object();
result["sEcho"]=sEcho;
result["iTotalRecords"]=response.hits.total
result["iTotalDisplayRecords"]=response.hits.total
result["aaData"]=response['hits']['hits'].map(functio(i){return i['_source']; })});
fnCallback(result);
},
error: function (xhr, textStatus, error){
}
}});
},
"oLanguage": {
"sLengthMenu": '<select>' +
'<option value="5">5</option>' +
'<option value="10">10</option>' +
'<option value="20">20</option>' +
'<option value="30">30</option>' +
'<option value="40">40</option>' +
'<option value="50">50</option>' +
'</select> Show'
},
"fnCreatedRow": function( nRow, aData, iDataIndex ) {
},
"fnDrawCallback": function(){
},
"aaSorting": [
[2, 'asc']
],
"aLengthMenu": [
[5, 15, 20, -1],
[5, 15, 20, "All"] // change per page values here
],
"iDisplayLength": 5
})
I wonder if its the way is true for this purpose.? anyway There is an error I couldn't get, in success; response is fine and I prepare result data for fncallback, but problem is when I click next pages shown data in page not changing I checked the query its fine but the problem is datatable inside here..
In normally I use same dt with php datasource everything works fine.. I create custom callback data for dt but something wrong..What should I do?
EDITED: the problem is display size.. but even it looks 5,10 or 50 it always 10 row in page and data not change with pagination