Rollback 3303, fixes #3311

Changes.md

@@ -1,8 +1,9 @@
 # Sidekiq Changes
 
-HEAD
+4.2.9
 -----------
 
+- Rollback [#3303] which broke Heroku Redis users [#3311]
 - Add support for TSTP signal, for Sidekiq 5.0 forward compatibility. [#3302]
 
 4.2.8

lib/sidekiq/redis_connection.rb

@@ -68,7 +68,13 @@ module Sidekiq
         end
 
         opts[:driver] ||= 'ruby'
-        opts[:reconnect_attempts] ||= 0
+
+        # Issue #3303, redis-rb will silently retry an operation.
+        # This can lead to duplicate jobs if Sidekiq::Client's LPUSH
+        # is performed twice but I believe this is much, much rarer
+        # than the reconnect silently fixing a problem; we keep it
+        # on by default.
+        opts[:reconnect_attempts] ||= 1
 
         opts
       end