High latency on puma

[MarwanTukhta]

Describe the bug
Puma seem to be adding latency to responses when we replaced passenger with puma, approximately 100ms more, everything else seem to be fine, even memory utilization is down compared to passenger, what do you think could be the reason for this?

Puma config:

max_threads_count = 1
min_threads_count = 1
threads min_threads_count, max_threads_count

port 3000

environment "production"

workers 30

on_worker_boot do
  SemanticLogger.reopen
# this made it worse
# ActiveRecord::Base.establish_connection if defined?(ActiveRecord)
end

fork_worker = true

preload_app!

activate_control_app

# this made it worse
# queue_requests false


bind 'unix:///var/run/puma.sock'
pidfile "/home/app/tmp/pids/puma.pid"
state_path "/home/app/tmp/pids/puma.state"

plugin :tmp_restart
plugin :yabeda
plugin :yabeda_prometheus

To Reproduce
above configuration on a rails app on a k8s pod with

  cpu: 5250m
  memory: 13Gi

Run it with:

bundle exec puma -C  ./config/puma.rb

Expected behavior
have the same latency as passenger

Desktop (please complete the following information):

• OS: Linux ubuntu 20.04
• Puma Version 6.2.2

[dentarg]

Hi, you may find threads like rails/rails#50450 and #2311 insightful (any maybe other issues here on the puma repo,

However, without sharing more info (ruby version? passenger setup?) and most importantly an example app (and benchmarks? there's one linked in the rails issue) that others can run I'm not sure anyone can help you finding the culprit for these 100ms

[MarwanTukhta]

Thanks @dentarg, these are the versions for each tool
Ruby: 2.7.7
RVM
Rails 6.0.6.1
Phusion Passenger(R) 6.0.17 with nginx with 25 workers.

[dentarg]

@MarwanTukhta I converted the issue to a discussion because it is not an actionable issue for Puma. You will need to investigate the problem on your own. It is not possible for anyone else to help out unless they have access to the exact same environment as you have.

Your setup having less latency with Passenger than Puma might not be a problem with Puma itself.