Elasticsearch response time - strange values - elasticsearch

Question

I'm querying simple Elasticsearch index with house numbers data.
".house-numbers": {
"mappings": {
"house-number": {
"properties": {
"id": {
"type": "keyword"
},
"value": {
"type": "text",
"index_options": "docs"
}
}
}
}
}
Then I'm querying data like POST http request
Request url
http://localhost:9200/.house-numbers/housenumber/_search
Headers:
Content-Type: text/plain
Content-Length: 55
Accept: */*
Accept-Encoding: gzip, deflate, br
Request body:
{
"size": 30,
"query": {
"match": {
"value": {
"query": "2 3"
}
}
}
}
Request returns data in 10ms - 30ms and everything works fine. Elasticsearch reponse parameter took is small in all cases 3-5ms.
When I change size in request body to "size": 35 response time has suddenly 500ms. Took parameter from Elasticsearch is the same. There are no special characters and size of response is very similar.
I tried many clients NEST, Postman, Fiddler to do these requests, every client has the same behaviour.
Setting of my elasticsearch contains only
http.compression : true
http.compression_level : 9
Setting of my jvm
"jvm": {
"timestamp": 1478108615141,
"uptime_in_millis": 17150141,
"mem": {
"heap_used_in_bytes": 1384307624,
"heap_used_percent": 66,
"heap_committed_in_bytes": 2077753344,
"heap_max_in_bytes": 2077753344,
"non_heap_used_in_bytes": 96403904,
"non_heap_committed_in_bytes": 101502976,
"pools": {
"young": {
"used_in_bytes": 324358632,
"max_in_bytes": 558432256,
"peak_used_in_bytes": 558432256,
"peak_max_in_bytes": 558432256
},
"survivor": {
"used_in_bytes": 69730304,
"max_in_bytes": 69730304,
"peak_used_in_bytes": 69730304,
"peak_max_in_bytes": 69730304
},
"old": {
"used_in_bytes": 990220848,
"max_in_bytes": 1449590784,
"peak_used_in_bytes": 1190046816,
"peak_max_in_bytes": 1449590784
}...
I tried different versions of elasticsearch
I tried different settings - turn off http.compression, change compression_level
I tried another hosts for elasticsearch
I have no idea what can cause this problem and I can't continue with my work.
Any idea where to look or how to proceed?

Answer 1

Of course problem was not in elasticsearch but in the http communication, especially when http compression was turned on
Hints to remove delays
close fiddler
disable firewall and anti-virus software
close all programs that possibly can intercept http communication