cache: replace memcache with redis.

Drop memcache. Use redis for all caching instead.

Gemfile

@@ -4,7 +4,6 @@ gem 'dotenv-rails', :require => "dotenv/rails-now"
 
 gem "rails", "~> 5.2"
 gem "pg"
-gem "dalli", :platforms => :ruby
 gem "delayed_job"
 gem "delayed_job_active_record"
 gem "simple_form"

Gemfile.lock

@@ -118,7 +118,6 @@ GEM
       safe_yaml (~> 1.0.0)
     crass (1.0.4)
     daemons (1.3.1)
-    dalli (2.7.10)
     delayed_job (4.1.7)
       activesupport (>= 3.0, < 5.3)
     delayed_job_active_record (4.1.3)
@@ -458,7 +457,6 @@ DEPENDENCIES
   capistrano3-unicorn
   cityhash
   daemons
-  dalli
   delayed_job
   delayed_job_active_record
   diff-lcs

INSTALL.debian

@@ -48,7 +48,7 @@ fi
 apt-get update
 apt-get -y install apt-transport-https
 apt-get -y install zlib1g-dev libglib2.0-dev
-apt-get -y install $LIBSSL_DEV_PKG build-essential automake libxml2-dev libxslt-dev ncurses-dev sudo libreadline-dev flex bison ragel memcached libmemcached-dev git curl libcurl4-openssl-dev sendmail-bin sendmail nginx ssh coreutils ffmpeg mkvtoolnix
+apt-get -y install $LIBSSL_DEV_PKG build-essential automake libxml2-dev libxslt-dev ncurses-dev sudo libreadline-dev flex bison ragel redis git curl libcurl4-openssl-dev sendmail-bin sendmail nginx ssh coreutils ffmpeg mkvtoolnix
 apt-get -y install libpq-dev postgresql-client
 apt-get -y install liblcms2-dev $LIBJPEG_TURBO_DEV_PKG libexpat1-dev libgif-dev libpng-dev libexif-dev
 

config/danbooru_default_config.rb

@@ -129,11 +129,6 @@ module Danbooru
       300
     end
 
-    # List of memcached servers
-    def memcached_servers
-      %w(127.0.0.1:11211)
-    end
-
     # After a post receives this many comments, new comments will no longer bump the post in comment/index.
     def comment_threshold
       40
@@ -786,6 +781,7 @@ module Danbooru
     end
 
     def redis_url
+      "redis://localhost:6379"
     end
   end
 

config/docker/compose.yml

@@ -10,11 +10,6 @@ services:
     image: redis:latest
     ports:
       - "6379:6379"
-  memcached:
-    image: memcached:alpine
-    ports:
-      - "11211:11211"
-    command: memcached
   archives:
     image: r888888888/archives
     command: sleep 1d
@@ -39,7 +34,6 @@ services:
       - RO_DATABASE_URL
       - DEBUG
       - ARCHIVE_DATABASE_URL
-      - DANBOORU_MEMCACHED_SERVERS
       - DANBOORU_AWS_SQS_ARCHIVE_URL
       - DANBOORU_PIXIV_LOGIN
       - DANBOORU_PIXIV_PASSWORD
@@ -65,6 +59,5 @@ services:
       - "3000:3000"
     depends_on:
       - db
-      - memcached
       - archives
       - redis

config/initializers/cache_store.rb

@@ -0,0 +1,26 @@
+Rails.application.configure do
+  if Rails.env.test?
+    cache_config = [:memory_store, { size: 32.megabytes }]
+  else
+    cache_config = [
+      :redis_cache_store,
+      {
+        url: Danbooru.config.redis_url,
+        namespace: nil,
+        connect_timeout:   30, # default: 20 seconds
+        write_timeout:    0.2, # default: 1 second
+        read_timeout:     0.2, # default: 1 second
+        reconnect_attempts: 0, # default: 0
+        error_handler: ->(method:, returning:, exception:) {
+          DanbooruLogger.log(exception, method: method, returning: returning)
+        }
+      }
+    ]
+  end
+
+  cache_store = ActiveSupport::Cache.lookup_store(cache_config)
+
+  config.cache_store = cache_store
+  config.action_controller.cache_store = cache_store
+  Rails.cache = cache_store
+end

config/initializers/z_dalli.rb

@@ -1,28 +0,0 @@
-Rails.application.configure do
-  begin
-    if Rails.env.test?
-      config.cache_store = :memory_store, { size: 32.megabytes }
-      config.action_controller.cache_store = :memory_store, { size: 32.megabytes }
-      Rails.cache = ActiveSupport::Cache.lookup_store(Rails.application.config.cache_store)
-    else
-      config.cache_store = :dalli_store, Danbooru.config.memcached_servers, { namespace: Danbooru.config.safe_app_name }
-      config.action_controller.cache_store = :dalli_store, Danbooru.config.memcached_servers, { namespace: Danbooru.config.safe_app_name }
-      Rails.cache = ActiveSupport::Cache.lookup_store(Rails.application.config.cache_store)
-
-      Rails.cache.dalli.alive!
-    end
-  rescue Dalli::RingError => e
-    puts "-" * 40
-    puts "WARNING! MEMCACHE SERVER NOT FOUND! You will experience performance degradation."
-    puts e.to_s
-    puts "-- BEGIN STACKTRACE --"
-    e.backtrace.each do |line|
-      puts line
-    end
-    puts "-- END STACKTRACE --"
-    puts "-" * 40
-
-    config.cache_store = :memory_store, { size: 32.megabytes }
-    Rails.cache = ActiveSupport::Cache.lookup_store(Rails.application.config.cache_store)
-  end
-end

script/install/app_server.sh

@@ -27,7 +27,7 @@ read VLAN_IP_ADDR
 echo "* Installing packages..."
 
 apt-get update
-apt-get -y install libssl-dev build-essential automake libxml2-dev libxslt-dev ncurses-dev sudo libreadline-dev flex bison ragel memcached libmemcached-dev git curl libcurl4-openssl-dev sendmail-bin sendmail nginx ssh coreutils ffmpeg mkvtoolnix
+apt-get -y install libssl-dev build-essential automake libxml2-dev libxslt-dev ncurses-dev sudo libreadline-dev flex bison ragel redis git curl libcurl4-openssl-dev sendmail-bin sendmail nginx ssh coreutils ffmpeg mkvtoolnix
 apt-get -y install libpq-dev postgresql-client
 apt-get -y install liblcms2-dev libjpeg-turbo8-dev libexpat1-dev libgif-dev libpng-dev libexif-dev