dropDatabase is slow and returns success immediately though it then blocks progress while running

db.createCollection("tinylsm",{storageEngine:{ wiredtiger:{configString: "type=lsm,lsm=(chunk_size=10MB)"}}})

2014-11-14T02:28:00.825-0500 I CONTROL  [initandlisten] MongoDB starting : pid=2253 port=27077 dbpath=/mnt/data0/asya/wtStandalone/ 64-bit host=erh-twinb

2014-11-14T02:28:00.825-0500 I CONTROL  [initandlisten] db version v2.8.0-rc1-pre-

2014-11-14T02:28:00.825-0500 I CONTROL  [initandlisten] git version: 81bb3e94b06d85f9aac2b014040b81ca7fc5c5bb

2014-11-14T02:28:00.825-0500 I CONTROL  [initandlisten] build info: Linux erh-twinb 3.5.0-54-generic #81~precise1-Ubuntu SMP Tue Jul 15 04:02:22 UTC 2014 x86_64 BOOST_LIB_VERSION=1_49

2014-11-14T02:28:00.825-0500 I CONTROL  [initandlisten] allocator: tcmalloc

2014-11-14T02:28:00.825-0500 I CONTROL  [initandlisten] options: { net: { port: 27077 }, processManagement: { fork: true }, storage: { dbPath: "/mnt/data0/asya/wtStandalone/", engine: "wiredtig

er", wiredtiger: { engineConfig: "cache_size=10G,checkpoint=(wait=10)" } }, systemLog: { destination: "file", path: "/mnt/data1/asya/wt91.log" } }

2014-11-14T02:28:00.825-0500 I STORAGE  [initandlisten] wiredtiger_open config: create,cache_size=62G,session_max=20000,extensions=[local=(entry=index_collator_extension)],statistics=(all),log=

(enabled=true,archive=true,path=journal),checkpoint=(wait=60,log_size=2GB),cache_size=10G,checkpoint=(wait=10)

2014-11-14T02:28:01.068-0500 I NETWORK  [initandlisten] waiting for connections on port 27077

2014-11-14T02:28:47.515-0500 I NETWORK  [initandlisten] connection accepted from 127.0.0.1:39360 #1 (1 connection now open)

2014-11-14T02:28:47.516-0500 I COMMANDS [conn1] dropDatabase ycsb starting

2014-11-14T02:28:47.687-0500 I COMMANDS [conn1] dropDatabase ycsb finished

2014-11-14T02:28:47.687-0500 I QUERY    [conn1] command ycsb.$cmd command: dropDatabase { dropDatabase: 1.0 } keyUpdates:0  reslen:55 170ms

2014-11-14T02:28:47.723-0500 I NETWORK  [initandlisten] connection accepted from 127.0.0.1:39361 #2 (2 connections now open)

2014-11-14T02:31:18.993-0500 I NETWORK  [initandlisten] connection accepted from 127.0.0.1:39362 #3 (3 connections now open)

2014-11-14T02:31:27.895-0500 I NETWORK  [initandlisten] connection accepted from 127.0.0.1:39363 #4 (4 connections now open)

2014-11-14T02:35:38.656-0500 I NETWORK  [conn1] end connection 127.0.0.1:39360 (3 connections now open)

2014-11-14T02:35:38.657-0500 I COMMANDS [conn3] serverStatus was very slow: { after basic: 0, after asserts: 0, after backgroundFlushing: 0, after connections: 0, after cursors: 0, after dur: 0

, after extra_info: 0, after globalLock: 0, after network: 0, after opcounters: 0, after opcountersRepl: 0, after storageEngine: 0, after wiredtiger: 258136, at end: 258136 }

2014-11-14T02:35:38.657-0500 I COMMANDS [conn2] serverStatus was very slow: { after basic: 0, after asserts: 0, after backgroundFlushing: 0, after connections: 0, after cursors: 0, after dur: 0

, after extra_info: 0, after globalLock: 0, after network: 0, after opcounters: 0, after opcountersRepl: 0, after storageEngine: 0, after wiredtiger: 408262, at end: 408262 }

2014-11-14T02:35:38.657-0500 I QUERY    [conn3] command admin.$cmd command: serverStatus { serverStatus: 1 } ntoreturn:1 keyUpdates:0  reslen:13949 259663ms

2014-11-14T02:35:38.657-0500 I QUERY    [conn2] command admin.$cmd command: serverStatus { serverStatus: 1.0 } keyUpdates:0  reslen:13949 410933ms

2014-11-14T02:35:38.657-0500 I NETWORK  [conn3] end connection 127.0.0.1:39362 (2 connections now open)

2014-11-14T02:35:38.663-0500 I NETWORK  [conn2] end connection 127.0.0.1:39361 (1 connection now open)

2014-11-14T02:35:38.698-0500 I NETWORK  [initandlisten] connection accepted from 127.0.0.1:39364 #5 (2 connections now open)

2014-11-14T02:35:38.704-0500 I NETWORK  [conn5] end connection 127.0.0.1:39364 (1 connection now open)

2014-11-14T02:35:38.737-0500 I NETWORK  [initandlisten] connection accepted from 127.0.0.1:39365 #6 (2 connections now open)

2014-11-14T02:35:38.873-0500 I QUERY    [conn6] command ycsb.$cmd command: create { create: "tinylsm", storageEngine: { wiredtiger: { configString: "type=lsm,lsm=(chunk_size=10MB)" } } } keyUpd

ates:0  reslen:37 134ms

2014-11-14T02:35:38.874-0500 I NETWORK  [conn6] end connection 127.0.0.1:39365 (1 connection now open)

-rw-rw-r-- 1 asya asya       4096 Nov 14 02:26 collection-0--7409934771532628199-000688.bf

-rw-rw-r-- 1 asya asya       4096 Nov 14 02:26 collection-0--7409934771532628199-000590.bf

-rw-rw-r-- 1 asya asya       4096 Nov 14 02:26 collection-0--7409934771532628199-000499.bf

-rw-rw-r-- 1 asya asya      36864 Nov 14 02:28 index-1-4425197065334213246.wt

-rw-rw-r-- 1 asya asya      36864 Nov 14 *02:28* collection-0-4425197065334213246.wt

-rw-rw-r-- 1 asya asya      36864 Nov 14 *02:35* _mdb_catalog.wt

-rw-rw-r-- 1 asya asya   82001920 Nov 14 *02:35* collection-0-2717636346714078045-000081.lsm

-rw-rw-r-- 1 asya asya     106496 Nov 14 02:35 collection-0-2717636346714078045-000081.bf

-rw-rw-r-- 1 asya asya   85880832 Nov 14 02:35 collection-0-2717636346714078045-000088.lsm