Remove idle_pool_size config

Clients created when idle_capacity is reached but not max_capacity
are discarded as soon as the client is checked back into the pool,
not when the connection is closed.

This means that allowing idle_capacity to be lower than max_capacity
essentially just makes the remaining clients a checkout timeout
deterrent that gets thrown away as soon as it is used. Not useful
for reusing connections whatsoever during peak load times

Author: syeopite

config/config.example.yml

@@ -214,25 +214,6 @@ https_only: false
 ##
 #pool_size: 100
 
-
-##
-## Max idle size of the HTTP pool used to connect to youtube. Each
-## domain ('youtube.com', 'ytimg.com', ...) has its own pool.
-##
-## This means that when releasing a connection back into the pool, it will
-## be closed if there are already more than idle_pool_size connections within
-## the pool
-##
-## Do note that idle connections are kept around forever without any way of
-## timing them out.
-##
-## When unset this value has the same value as pool_size 
-##
-## Accepted values: a positive integer
-## Default: <none> (internally this means that it has the same value as pool_size)
-##
-#idle_pool_size:
-
 ##
 ## Amount of seconds to wait for a client to be free from the pool
 ## before raising an error

src/invidious.cr

@@ -94,7 +94,6 @@ SOFTWARE = {
 
 YT_POOL = Invidious::ConnectionPool::Pool.new(
   max_capacity: CONFIG.pool_size,
-  idle_capacity: CONFIG.idle_pool_size,
   timeout: CONFIG.pool_checkout_timeout
 ) do
   next make_client(YT_URL, force_resolve: true)
@@ -106,15 +105,13 @@ GGPHT_URL = URI.parse("https://yt3.ggpht.com")
 
 GGPHT_POOL = Invidious::ConnectionPool::Pool.new(
   max_capacity: CONFIG.pool_size,
-  idle_capacity: CONFIG.idle_pool_size,
   timeout: CONFIG.pool_checkout_timeout
 ) do
   next make_client(GGPHT_URL, force_resolve: true)
 end
 
 COMPANION_POOL = Invidious::ConnectionPool::Pool.new(
   max_capacity: CONFIG.pool_size,
-  idle_capacity: CONFIG.idle_pool_size
 ) do
   companion = CONFIG.invidious_companion.sample
   next make_client(companion.private_url, use_http_proxy: false)

src/invidious/config.cr

@@ -160,8 +160,6 @@ class Config
 
   # Max pool size for HTTP requests to youtube.com and ytimg.com (each domain has a separate pool)
   property pool_size : Int32 = 100
-  # Idle pool size for HTTP requests to youtube.com and ytimg.com (each domain has a separate pool)
-  property idle_pool_size : Int32? = nil
 
   # Amount of seconds to wait for a client to be free from the pool before rasing an error
   property pool_checkout_timeout : Float64 = 5

src/invidious/connection/pool.cr

@@ -7,18 +7,13 @@ module Invidious::ConnectionPool
     def initialize(
       *,
       max_capacity : Int32 = 5,
-      idle_capacity : Int32? = nil,
       timeout : Float64 = 5.0,
       &client_factory : -> HTTP::Client
     )
-      if idle_capacity.nil?
-        idle_capacity = max_capacity
-      end
-
       pool_options = DB::Pool::Options.new(
         initial_pool_size: 0,
         max_pool_size: max_capacity,
-        max_idle_pool_size: idle_capacity,
+        max_idle_pool_size: max_capacity,
         checkout_timeout: timeout
       )
 
@@ -106,7 +101,6 @@ module Invidious::ConnectionPool
 
       pool = ConnectionPool::Pool.new(
         max_capacity: CONFIG.pool_size,
-        idle_capacity: CONFIG.idle_pool_size,
         timeout: CONFIG.pool_checkout_timeout
       ) do
         next make_client(url, force_resolve: true)