Merge pull request #439 from prometheus/beorn7/remove-deadlock

Remove a deadlock during shutdown.

storage/local/storage.go

@@ -424,7 +424,7 @@ func (s *memorySeriesStorage) preloadChunksForRange(
 func (s *memorySeriesStorage) handleEvictList() {
 	ticker := time.NewTicker(maxEvictInterval)
 	count := 0
-loop:
+
 	for {
 		// To batch up evictions a bit, this tries evictions at least
 		// once per evict interval, but earlier if the number of evict
@@ -450,12 +450,20 @@ loop:
 				s.maybeEvict()
 			}
 		case <-s.evictStopping:
-			break loop
-		}
-	}
+			// Drain evictRequests to not let requesters hang.
+			for {
+				select {
+				case <-s.evictRequests:
+					// Do nothing.
+				default:
 					ticker.Stop()
 					glog.Info("Chunk eviction stopped.")
 					close(s.evictStopped)
+					return
+				}
+			}
+		}
+	}
 }
 
 // maybeEvict is a local helper method. Must only be called by handleEvictList.