How sum in MongoDB nested document when the KEY is uncertain ？ - mongodb

Question

First of all the status codes("200","404" or other) and time("1000","2000"..) are uncertain,
I want to calculate the number(5, 6 ...) for each status codes.
For example: {"200" : 11}, {"404" :11} or {"total" : 22}
Data Structure :
"_id" : "xxxxx"
"domain" : "www.test.com"
"status" : [
{"200" : [ {"1000" : 5}, {"2000": 6} ...]},
{"404" : [ {"1000" : 5}, {"2000": 6} ...]}
....
]
Any fantastic methods in MongoDB ?
Thank you for your help

Answer 1

Don't use data, like dates, as keys. Data belongs in values. The HTTP status codes are enumerated - you know all the possibilities - so you can use those as keys if you want to. From the look of the documents, you are storing information about requests to a page in a page document with the requests in an array. It's not a great idea to have an unbounded, constantly growing array in a document. I'd suggest refactoring the data to be request documents with the address denormalized into each:
{
"_id" : ObjectId(...),
"status" : 404,
"date" : ISODate("2014-10-30T18:23:09.471Z"),
"domain" : "www.test.com"
}
and then you can get the total number of 404 requests to test.com with the aggregation
db.requests.aggregate([
{ "$match" : { "domain" : "www.test.com" } },
{ "$group" : { "_id" : "$status", "count" : { "$sum" : 1 } } }
])
Index on domain to make it fast.

Answer 2

I think you can use the aggregation framework to pull something like that.
Check this:
db.errors.aggregate([{$unwind: "$status"}, {$group: {_id: "$status", total:{$sum:1}}}])
It will render a result like this:
...
"result" : [
{
"_id" : {
"500" : [
{
"1000" : 5
},
{
"2000" : 6
}
]
},
"total" : 1
},
...
The "total" field has the count that you're looking for.
Hope this helps.
Regards!