Software versions:
mongod 1.8.2
node 1.4.5
node-mongodb-native
A node.js script node_mongodb_log_app.js is shown below.
GLOBAL.DEBUG = true;
var sys = require('sys');
var Db = require('mongodb').Db,
Connection = require('mongodb').Connection,
Server = require('mongodb').Server,
BSON = require('mongodb').BSONNative;
var db = new Db('logdb', new Server('127.0.0.1', 27017, {}), {native_parser: true});
var filter = null;
var lon = (process.ARGV[2]) ? Number(process.ARGV[2]): null;
var lat = (process.ARGV[3]) ? Number(process.ARGV[3]): null;
if(lat != null && lon != null){
filter = { query: { loc : { $near: [lon, lat]}}};
sys.puts(sys.inspect(filter));
}
db.open(function(error, db) {
var map_request_size = function(){
emit(1, this.size);
}
var reduce = function (k, vals) {
var sum = 0;
vals.forEach(function (v) {sum += v;});
return sum;
}
// query all results, total bandwith
db.collection('logentry', function(error, collection){
if(filter != null){
collection.mapReduce(map_request_size, reduce, filter,
function(error, collection){
collection.find(function(error, cursor){
cursor.each(function(error, mrdoc){
if(mrdoc != null){
sys.puts(mrdoc.value);
}
db.close();
});
});
});
}
else{
collection.mapReduce(map_request_size, reduce,
function(error, collection){
collection.find(function(error, cursor){
cursor.each(function(error, mrdoc){
if(mrdoc != null){
sys.puts(mrdoc.value);
}
db.close();
});
});
});
}
});
});
We want to accumulate all file download into a single number of bytes. For that we execute the script without parameters:
$ node node_mongodb_log_app.js
204612741925
If we want to analyze consumption near a geographic location, we issue a call like this:
$ node node_mongodb_log_app.js -108 32.6
{ query: { loc: { '$near': [Object] } } }
30435795
