Use 3scale's redis-rb fork

Gemfile.base

@@ -52,7 +52,6 @@ gem 'daemons', '= 1.2.4'
 # Production gems
 gem 'rake', '~> 13.0'
 gem 'builder', '= 3.2.3'
-gem 'redis', '= 4.1.1'
 # Use a patched resque to allow reusing their Airbrake Failure class
 gem 'resque', git: 'https://github.com/3scale/resque', branch: '3scale'
 gem 'rack', '~> 2.0.8'
@@ -63,3 +62,8 @@ gem 'bugsnag', '~> 6', require: nil
 gem 'yabeda-prometheus', '~> 0.5.0'
 gem 'async-redis', '~> 0.4.1'
 gem 'falcon', '~> 0.35'
+
+# Use a patched redis-rb that fixes an issue when trying to connect with
+# sentinels and avoids retrying calls when there's a timeout to prevent
+# duplicated commands. It's based on version 4.1.3.
+gem 'redis', git: 'https://github.com/3scale/redis-rb', branch: 'apisonator'

Gemfile.lock

@@ -5,6 +5,13 @@ GIT
   specs:
     puma (2.15.3)
 
+GIT
+  remote: https://github.com/3scale/redis-rb
+  revision: 35301b3d952975300a4cb30d408ae3b5969d0440
+  branch: apisonator
+  specs:
+    redis (4.1.3)
+
 GIT
   remote: https://github.com/3scale/resque
   revision: 88839e71756ea9b6edfc9426a0af71e94109c135
@@ -182,7 +189,6 @@ GEM
     rack-test (0.8.2)
       rack (>= 1.0, < 3)
     rake (13.0.1)
-    redis (4.1.1)
     redis-namespace (1.6.0)
       redis (>= 3.0.4)
     reentrant_flock (0.1.1)
@@ -297,7 +303,7 @@ DEPENDENCIES
   rack (~> 2.0.8)
   rack-test (~> 0.8.2)
   rake (~> 13.0)
-  redis (= 4.1.1)
+  redis!
   resque!
   resque_spec (~> 0.17.0)
   resque_unit (~> 0.4.4)!

Gemfile.on_prem.lock

@@ -5,6 +5,13 @@ GIT
   specs:
     puma (2.15.3)
 
+GIT
+  remote: https://github.com/3scale/redis-rb
+  revision: 35301b3d952975300a4cb30d408ae3b5969d0440
+  branch: apisonator
+  specs:
+    redis (4.1.3)
+
 GIT
   remote: https://github.com/3scale/resque
   revision: 88839e71756ea9b6edfc9426a0af71e94109c135
@@ -170,7 +177,6 @@ GEM
     rack-test (0.8.2)
       rack (>= 1.0, < 3)
     rake (13.0.1)
-    redis (4.1.1)
     redis-namespace (1.6.0)
       redis (>= 3.0.4)
     reentrant_flock (0.1.1)
@@ -278,7 +284,7 @@ DEPENDENCIES
   rack (~> 2.0.8)
   rack-test (~> 0.8.2)
   rake (~> 13.0)
-  redis (= 4.1.1)
+  redis!
   resque!
   resque_spec (~> 0.17.0)
   resque_unit (~> 0.4.4)!

lib/3scale/backend.rb

@@ -5,7 +5,6 @@
 require 'hiredis'
 
 require 'redis'
-require '3scale/backend/extensions/redis'
 
 require 'resque'
 require 'securerandom'

lib/3scale/backend/storage_helpers.rb

@@ -44,9 +44,13 @@ class << self
               connect_timeout: 5,
               read_timeout: 3,
               write_timeout: 3,
-              # this is set to zero to avoid potential double transactions
-              # see https://github.com/redis/redis-rb/issues/668
-              reconnect_attempts: 0,
+              # Note that we can set reconnect_attempts to >= 0 because we use
+              # our redis-rb fork which implements a workaround for this issue
+              # that shows that when there might be duplicated transactions when
+              # there's a timeout: https://github.com/redis/redis-rb/issues/668
+              # We should investigate if there are edge cases that can lead to
+              # duplicated commands because of this setting.
+              reconnect_attempts: 1,
               # use by default the C extension client
               driver: :hiredis
           }.freeze