Keepalive support?

[thelinuxlich]

If it has, how do we use it?

[mamantoha]

I don't know if Crystal build-in HTTP::Client module supports this. Keep in mind crest is just a wrapper around HTTP::Client

How to test keep-alive is working on the client end?

[mamantoha]

Got it.

The Crest::Resource object allows to use a persistent connection.

Using new connection for each HTTP request:

start_time = Time.utc

url = "https://httpbin.org/get"

50.times do
  response = Crest.get(url)
  json = JSON.parse(response.body)
  puts json["origin"]
end

puts "--- #{Time.utc - start_time} seconds ---"

Using persistent connection for all HTTP requests:

start_time = Time.utc

client = Crest::Resource.new("https://httpbin.org")

path = "/get"

50.times do
  response = client.get(path)
  json = JSON.parse(response.body)
  puts json["origin"]
end

puts "--- #{Time.utc - start_time} seconds ---"

I ran both scripts five times and the result was very interesting.

Average time with keep-alive/persistent connections: around 8 seconds Average time with new connections: around 30 seconds