In the Jenkins installations with many executors queue becomes a critical resource. When many executors / scheduler try to take the job at the same time, queue visualization may lock the web interface:

"Handling POST /ajaxBuildQueue : RequestHandlerThread180" daemon prio=10 tid=0x00002aaacccdc000 nid=0x378c waiting for monitor entry [0x0000000059b2c000]
java.lang.Thread.State: BLOCKED (on object monitor)
at hudson.model.Queue.getItems(Queue.java:641)

• waiting to lock <0x0000000680060bf0> (a hudson.model.Queue)
  at hudson.model.Queue$CachedItemList.get(Queue.java:196)
  at hudson.model.Queue.getApproximateItemsQuickly(Queue.java:671)
  at hudson.model.View.getApproximateQueueItemsQuickly(View.java:457)
  at sun.reflect.GeneratedMethodAccessor248.invoke(Unknown Source)

getApproximateItemsQuickly() updates its cache every 1 second. I propose to make this time configurable