Merge pull request #11131 from neinteractiveliterature/adjust-scaling-plan

Adjust scaling plan

Author: nbudin

.gitignore

@@ -103,3 +103,7 @@ cookbooks
 
 # Vite
 /vite.config.mts.timestamp-*.mjs
+
+# Autoscaling simulation output
+/scaling-graph.csv
+/scaling-graph.png

app/services/autoscale_servers_service.rb

@@ -1,27 +1,16 @@
-# Script to generate graph:
-# require "csv"
-# Time.zone = "America/New_York"
-# time = Time.local(2022, 10, 31)
-# data = []
-# while time < Time.local(2022, 11, 4)
-#   data << [time, AutoscaleServersService.scaling_target_for(time)]
-#   time += 15.minutes
-# end
-# CSV.open("scaling-graph.csv", "w") do |csv|
-#   csv << %w[Time Servers]
-#   data.each { |row| csv << row }
-# end
+# To simulate the effect of autoscaling as a CSV file:
+# bin/rails runner script/generate_simulated_autoscaling_graph.rb
 
 class AutoscaleServersService < CivilService::Service
   USERS_PER_INSTANCE = ENV.fetch("AUTOSCALE_USERS_PER_INSTANCE", "40").to_i
-  MIN_INSTANCES = ENV.fetch("AUTOSCALE_MIN_INSTANCES", "1").to_i
+  MIN_INSTANCES = ENV.fetch("AUTOSCALE_MIN_INSTANCES", "2").to_i
   MIN_INSTANCES_FOR_SIGNUP_OPENING = ENV.fetch("AUTOSCALE_MIN_INSTANCES_FOR_SIGNUP_OPENING", "2").to_i
-  MAX_INSTANCES = ENV.fetch("AUTOSCALE_MAX_INSTANCES", "8").to_i
+  MAX_INSTANCES = ENV.fetch("AUTOSCALE_MAX_INSTANCES", "10").to_i
   SIGNUP_OPENING_LOOKAHEAD_TIME = ENV.fetch("AUTOSCALE_SIGNUP_OPENING_LOOKAHEAD_HOURS", "48").to_i.hours
   SIGNUP_OPENING_RAMP_UP_LOOKAHEAD_TIME = ENV.fetch("AUTOSCALE_SIGNUP_OPENING_RAMP_UP_LOOKAHEAD_HOURS", "2").to_i.hours
   SIGNUP_OPENING_FULL_THROTTLE_LOOKAHEAD_TIME =
     ENV.fetch("AUTOSCALE_SIGNUP_OPENING_FULL_THROTTLE_LOOKAHEAD_HOURS", "1").to_i.hours
-  SIGNUP_OPENING_DECAY_TIME = ENV.fetch("AUTOSCALE_SIGNUP_OPENING_DECAY_TIME", "1").to_i.hours
+  SIGNUP_OPENING_DECAY_TIME = ENV.fetch("AUTOSCALE_SIGNUP_OPENING_DECAY_TIME", "6").to_i.hours
   SIGNUP_OPENING_LOOKBACK_TIME = ENV.fetch("AUTOSCALE_SIGNUP_OPENING_LOOKBACK_TIME", "6").to_i.hours
 
   def self.scaling_target_for_signup_opening(convention)

script/generate_simulated_autoscaling_graph.gnuplot

@@ -0,0 +1,13 @@
+set terminal png size 1200,600
+set output 'scaling-graph.png'
+set datafile separator ','
+set xdata time
+set timefmt '%Y-%m-%d %H:%M:%S'
+set format x '%I:%M%p'
+set xlabel 'Time'
+set ylabel 'Servers'
+set title 'Autoscaling Servers'
+set autoscale yfix
+set yrange [0:*]
+set offsets 0,0,graph 0.1,0
+plot 'scaling-graph.csv' skip 1 using 1:2 with lines notitle

script/generate_simulated_autoscaling_graph.rb

@@ -0,0 +1,23 @@
+require "csv"
+
+Time.use_zone "America/New_York" do
+  time = Time.zone.local(2025, 11, 24, 12)
+  data = []
+  while time < Time.zone.local(2025, 11, 25, 12)
+    data << [time, AutoscaleServersService.scaling_target_for(time)]
+    time += 15.minutes
+  end
+
+  puts "Writing simulated autoscaling data to scaling-graph.csv"
+
+  CSV.open("scaling-graph.csv", "w") do |csv|
+    csv << %w[Time Servers]
+    data.each { |row| csv << row }
+  end
+
+  puts "Plotting graph to scaling-graph.png"
+
+  system <<~SH
+    gnuplot -c ./script/generate_simulated_autoscaling_graph.gnuplot
+  SH
+end