Simple script showing effective multithreading with vanilla Ruby

net_http_multithreaded.rb

# API endpoint that takes ~3.8s to respond
TARGET_URI = 'http://localhost:3000/delay'
SAMPLE_BODY = {}

def post_body!                                                                                       
  Net::HTTP.post_form(TARGET_URI, SAMPLE_BODY).body                                                  
  print ?.                                                                                           
end                                                                                                  
                                                                                                     
1.upto(5).each do |concurrency|                                                                      
  threads = nil                                                                                      
  Benchmark.bm do |b|                                                                                
    b.report { threads = Array.new(concurrency) { Thread.new { post_body! } }; threads.each(&:join) }
    p "threads: #{threads.count}"                                                                    
  end                                                                                                
end

# $ ruby app/services/create_postcards.rb             
#       user     system      total        real       
# .  0.010000   0.000000   0.010000 (  3.901472)     
# "threads: 1"                                        
#       user     system      total        real       
# ..  0.000000   0.000000   0.000000 (  3.866117)    
# "threads: 2"                                        
#       user     system      total        real       
# ...  0.010000   0.000000   0.010000 (  3.867366)   
# "threads: 3"                                        
#       user     system      total        real       
# ....  0.010000   0.010000   0.020000 (  3.883346)  
# "threads: 4"                                        
#       user     system      total        real       
# .....  0.010000   0.000000   0.010000 (  3.885859) 
# "threads: 5"