From e695e0554f3535f2b551c6992921b04c4818cdd5 Mon Sep 17 00:00:00 2001
From: Jason Ardell <ardell@gmail.com>
Date: Wed, 16 Jan 2013 16:56:15 -0500
Subject: [PATCH] Clear workers in redis before terminating worker threads.
 #623

---
 lib/sidekiq/manager.rb | 21 +++++++++++++--------
 1 file changed, 13 insertions(+), 8 deletions(-)

diff --git a/lib/sidekiq/manager.rb b/lib/sidekiq/manager.rb
index 83f26c7d..a16492bc 100644
--- a/lib/sidekiq/manager.rb
+++ b/lib/sidekiq/manager.rb
@@ -113,19 +113,13 @@ module Sidekiq
           logger.info("Still waiting for #{@busy.size} busy workers")
 
           Sidekiq.redis do |conn|
-            logger.debug { "Clearing workers in redis" }
-            workers = conn.smembers('workers')
-            workers_to_remove = workers.select do |worker_name|
-              worker_name =~ /:#{process_id}-/
-            end
-            conn.srem('workers', workers_to_remove)
-
             # Re-enqueue terminated jobs
             # NOTE: You may notice that we may push a job back to redis before
             # the worker thread is terminated. This is ok because Sidekiq's
             # contract says that jobs are run AT LEAST once. Process termination
             # is delayed until we're certain the jobs are back in Redis because
             # it is worse to lose a job than to run it twice.
+            logger.debug { "Re-queueing terminated jobs" }
             jobs_to_requeue = {}
             @busy.each do |processor|
               # processor is an actor proxy and we can't call any methods
@@ -139,7 +133,18 @@ module Sidekiq
               conn.rpush(queue, jobs)
             end
 
-            # Lastly, terminate worker threads
+            # Clearing workers in Redis
+            # NOTE: we do this before terminating worker threads because the
+            # process will likely receive a hard shutdown soon anyway, which
+            # means the threads will killed.
+            logger.debug { "Clearing workers in redis" }
+            workers = conn.smembers('workers')
+            workers_to_remove = workers.select do |worker_name|
+              worker_name =~ /:#{process_id}-/
+            end
+            conn.srem('workers', workers_to_remove)
+
+            logger.debug { "Terminate worker threads" }
             @busy.each do |processor|
               processor.terminate if processor.alive?
             end