Elasticsearch - Range query doesn't work - date

Question

To try this error I have tried with Elasticsearch 2.x and 5.x but doesn't work in any of these.
I have lots of logs saved in my Elasticsearch instance. They have a field called timestamp whose format is "YYYY-MM-dd HH-mm-ss.SSS" (for example, "2017-11-02 00:00:00.000"). When I try to send a query via POSTMAN which is this:
{
"query": {
"range": {
"timestamp": {
"gte": "2017-10-21 00:00:00.000",
"lte": "2017-10-27 00:00:00.000"
}
}
}
}
I receive nothing and I there are more than 500 logs in that range. What am I doing wrong?
EDIT:
My index (loganalyzer):
{
"loganalyzer" : {
"aliases" : { },
"mappings" : {
"logs" : {
"properties" : {
"entireLog" : {
"type" : "string"
},
"formattedMessage" : {
"type" : "string"
},
"id" : {
"type" : "string"
},
"level" : {
"type" : "string"
},
"loggerName" : {
"type" : "string"
},
"testNo" : {
"type" : "string"
},
"threadName" : {
"type" : "string"
},
"timestamp" : {
"type" : "string"
}
}
}
},
"settings" : {
"index" : {
"refresh_interval" : "1s",
"number_of_shards" : "5",
"creation_date" : "1507415366223",
"store" : {
"type" : "fs"
},
"number_of_replicas" : "1",
"uuid" : "9w3QQQc0S0K0NcKtOERtTw",
"version" : {
"created" : "2040699"
}
}
},
"warmers" : { }
}
}
What I receive sending the request:
{
"took": 429,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"failed": 0
},
"hits": {
"total": 0,
"max_score": null,
"hits": []
}
}
And status 200 (OK).

Answer 1

Your edit with the mappings indicates the problem. The reason you aren't getting any result is because it's attempting to find a "range" for the string you're providing against the values of the field in your index, which are also treated as a string.
"timestamp" : {
"type" : "string"
}
Here's the elastic documentation on that mapping type
You need to apply a date mapping to that field before indexing, or reindex to a new index that has that mapping applied prior to ingestion.
Here is what the mapping request could look like, conforming to your timestamp format:
PUT loganalyzer
{
"mappings": {
"logs": {
"properties": {
"timestamp": {
"type": "date",
"format": "YYYY-MM-dd HH-mm-ss.SSS"
}
}
}
}
}