cache: replace memcache with redis.

Drop memcache. Use redis for all caching instead.

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
+      - 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