New defaults for autoscaling decay based on what we saw at Intercon signups

Author: nbudin

app/services/autoscale_servers_service.rb

@@ -3,14 +3,14 @@
 
 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)