Refactor redis usage to avoid nil result from multi, see redis/redis-rb#490

Changes.md

@@ -2,6 +2,7 @@ HEAD
 -----------
 
 - Log Sidekiq Pro's Batch ID if available [#2076]
+- Refactor Processor Redis usage to avoid redis/redis-rb#490 [#]
 
 
 3.3.0

lib/sidekiq/processor.rb

@@ -98,26 +98,26 @@ module Sidekiq
         yield
       rescue Exception
         retry_and_suppress_exceptions do
-          Sidekiq.redis do |conn|
           failed = "stat:failed:#{Time.now.utc.to_date}"
-            result = conn.multi do
+          Sidekiq.redis do |conn|
+            conn.multi do
               conn.incrby("stat:failed", 1)
               conn.incrby(failed, 1)
+              conn.expire(failed, STATS_TIMEOUT)
             end
-            conn.expire(failed, STATS_TIMEOUT) if result.last == 1
           end
         end
         raise
       ensure
         retry_and_suppress_exceptions do
-          Sidekiq.redis do |conn|
           processed = "stat:processed:#{Time.now.utc.to_date}"
-            result = conn.multi do
+          Sidekiq.redis do |conn|
+            conn.multi do
               conn.hdel("#{identity}:workers", thread_identity)
               conn.incrby("stat:processed", 1)
               conn.incrby(processed, 1)
+              conn.expire(processed, STATS_TIMEOUT)
             end
-            conn.expire(processed, STATS_TIMEOUT) if result.last == 1
           end
         end
       end