关于ConcurrentHashMap的诡异问题

[线程pool-157-thread-39] [2016-10-26 15:01:51.597] [INFO] [allocate_cache] [<34317662,13641444779>准备多线程]
[线程pool-73-thread-18] [2016-10-26 15:01:51.597] [INFO] [allocate_cache] [<34317662,13641444779>派发缓存开始]
[线程pool-73-thread-18] [2016-10-26 15:01:51.599] [INFO] [allocate_cache] [<34317662,13641444779>派发缓存结束]
[线程pool-157-thread-34] [2016-10-26 15:02:04.133] [INFO] [allocate_cache] [<34317662,13641444779>准备多线程]
[线程pool-73-thread-25] [2016-10-26 15:02:04.133] [INFO] [allocate_cache] [<34317662,13641444779>派发缓存开始]
[线程pool-73-thread-25] [2016-10-26 15:02:04.133] [INFO] [allocate_cache] [<34317662,13641444779>派发缓存命中]
[线程pool-315-thread-24] [2016-10-26 15:02:10.663] [INFO] [allocate_cache] [<34317662,13641444779>准备多线程]
[线程pool-231-thread-42] [2016-10-26 15:02:10.663] [INFO] [allocate_cache] [<34317662,13641444779>派发缓存开始]
[线程pool-231-thread-42] [2016-10-26 15:02:10.664] [INFO] [allocate_cache] [<34317662,13641444779>派发缓存结束]
[线程pool-157-thread-34] [2016-10-26 15:02:21.115] [INFO] [allocate_cache] [<34317662,13641444779>准备多线程]
[线程pool-73-thread-2] [2016-10-26 15:02:21.116] [INFO] [allocate_cache] [<34317662,13641444779>派发缓存开始]
[线程pool-73-thread-2] [2016-10-26 15:02:21.116] [INFO] [allocate_cache] [<34317662,13641444779>派发缓存命中]
[线程pool-157-thread-34] [2016-10-26 15:02:30.882] [INFO] [allocate_cache] [<34317662,13641444779>准备多线程]
[线程pool-73-thread-21] [2016-10-26 15:02:30.882] [INFO] [allocate_cache] [<34317662,13641444779>派发缓存开始]
[线程pool-73-thread-21] [2016-10-26 15:02:30.882] [INFO] [allocate_cache] [<34317662,13641444779>派发缓存命中]从上面LOG可以看出第三次轮训的时候，缓存没有取到。然后我去查清除的LOG，发现了有2条清除记录。
key是一样的，但是value可以看到是不一样的。[线程pool-157-thread-44] [2016-10-26 15:13:01.255] [INFO][将订单号为34317662的缓存清除，该订单缓存时间为1477465311597]
[线程pool-315-thread-37] [2016-10-26 15:16:00.989] [INFO]  [将订单号为34317662的缓存清除，该订单缓存时间为1477465330663]