HBase长时间无法关闭［Waiting on regionserver(s) to go down］
为了释放已经删除的region，重启hbase，执行./bin/。
等了很久还未关闭，查看master日志，显示一直在等待regionserver
2015-07-08 09:11:25,800 INFO : Waiting on regionserver(s) to go down Colander-hb01,60020,1435801056660
再去查看此regionserver情况，日志显示Region is not online
2015-07-08 09:17:34,419 DEBUG : NotServingRegionException; Region is not online: COLANDER_DownloadedURL,:http/t/nisearch/Camino+sangriento+6/_cid_15_time_100_sort_score_display_album_high_24?sfilter=1,1417099858158.e9e95f20d0f45860aa0778a5b6e97dbc.
陷入了死循环的情况，永远也无法完成关闭。
尝试手动强制关闭regionserver，成功了
./bin/ stop regionserver
随即，hbase成功关闭。