最近对mongoDB 性能测试，200万条数据，文件大小800MB。其中一个字段是一个数组，最大可能包含上万条id,平均几百条。
最后发现只读情况下性能很好，基本在1ms以内就能返回，问题出在写上面。同步数据的时候的时候居然有这种update导致lock很高：
Tue Mar 5 13:36:05 [conn16962] update duitangdb.blogAlbum query: { _id: "1913010" } update: { _id: "1913010", count: 457, name: "我为壁纸狂！", blogs: [ 58681345, 58664963, 66496522, 58675213, 58654739, 66496533, 58654744, 58679321, 58681379, 58679337, 58681393, 58650678, 58681402, 58650689, 58681418, 66496587, 58644556, 58681421, 58665043, 58679380, 66496600, 58650713, 58681434, 58654813, 58681438, 58650719, 58644578, 58681444, 58654821, 58650726, 58644586, 66496623, 58681704, 58658932, 58679419, 58654844, 58658945, 58644613, 66496651, 58675224, 58644628, 58681502, 58665123, 58681508, 66496682, 58679468, 58654894, 58650799, 58665141, 60485815, 58679482, 58650811, 58659005, 58687681, 58681540, 58659016, 58650826, 58659025, 66496722, 58650835, 58679509, 58659032, 58665180, 58650845, 58681566, 60485856, 58665186, 66496744, 58659052, 58681584, 58650865, 59017458, 58659060, 58681592, 58665210, 58681596, 58679553, 58665218, 66496774, 58681611, 58659087, 58665234, 66496899, 66496790, 58659096, 58659104, 58655010, 66496803, 58687780, 66496561, 59017513, 58650927, 58655027, 58659134, 66496832, 58681667, 58659144, 58665289, 58665291, 58650959, 66496851, 58650964, 58659157, 58681686, 58655066, 58681691, 66494822, 58679655, 58689896, 58681708, 58665326, 66496882, 66494835, 58681717, 58650481, 58651008, 58689921, 58655107, 58665348, 66495894, 58659906, 58659214, 60486044, 66494878, 66496936, 58689961, 58687916, 60486062, 58644913, 66496946, 58681790, 58687935, 58659269, 58681741, 58659289, 58659300, 58690021, 66497008, 58688595, 58644564, 58690043, 66494974, 58690058, 66497040, 66495001, 58690076, 66495053, 66497070, 58638895, 58645044, 66495032, 66497081, 58645053, 58645062, 60486218, 58665058, 66497109, 58638939, 58690145, 66495076, 58679398, 60488295, 58638958, 66497140, 58644926, 58638969, 58689983, 58645121, 66497156, 66495109, 58733202, 66495125, 66497181, 58639015, 66495151, 66496490, 58690227, 58650740, 66497215, 58655441, 58689933, 58655467, 58682123, 58645269, 58690327, 58678042, 58678057, 58655531, 58649391, 58645302, 58649403, 58678081, 58655554, 58645320, 58645327, 58644280, 58680462, 58650426, 58645343, 58654865, 66495337, 66495364, 66192264, 58659727, 58649488, 66192275, 58659756, 58678191, 58735537, 58649525, 58682304, 58659779, 58649542, 58649545, 58655691, 58657741, 60484771, 58655702, 66305871, 58645468, 58678246, 58659822, 58655730, 58680310, 58645501, 58657791, 58659840, 58678283, 58657807, 58649616, 58678303, 58659877, 58657832, 58659894, 58649661, 58690626, 58680390, 58649673, 58678351, 58735696, 58690643, 58659926, 58678367, 58690662, 58680423, 60484716, 58680431, 58649725, 58678398, 58649739, 58690702, 58649750, 60484759, 58680474, 58674715, 58649764, 58644337, 58680493, 58649774, 59219121, 58678456, 58649786, 58690753, 58654583, 58735823, 58680542, 58658016, 58680552, 58658025, 58690796, 58735859, 58681557, 58658054, 58658061, 58664206, 66495759, 58674450, 58649476, 58664224, 66495782, 58674472, 58658116, 66495813, 58674505, 58680653, 58658128, 64224594, 58674520, 66495835, 60484961, 58680678, 66495847, 58650947, 58678650, 66495868, 58654078, 58680712, 58674574, 58664340, 58654102, 58680729, 58650015, 58664355, 58680743, 66495915, 58674614, 58681588, 60485051, 58680766, 66495935, 58664384, 58654149, 60485063, 66495945, 58654157, 58664399, 58674646, 60485080, 59017466, 58664414, 58674663, 66495985, 60485111, 58654210, 58674696, 66496009, 58664458, 58654222, 58664467, 66496027, 58664477, 58664486, 58674730, 58654269, 59017483, 58664522, 58650193, 58664536, 58664545, 58674787, 58654312, 58674794, 66497127, 58689136, 58654321, 58681278, 58674808, 58654332, 58664573, 58654707, 60485252, 58654342, 58654351, 66496151, 58664613, 58674856, 66496175, 58644146, 58681011, 58664629, 58674554, 58664638, 58678975, 66496193, 58674887, 58679000, 66496217, 58644190, 58650342, 58644203, 66496243, 58650356, 58679029, 58665257, 58644216, 58674941, 58650366, 58644227, 58679049, 66496266, 58806232, 58674968, 66496132, 66496289, 58679076, 58644263, 58650412, 58644269, 58681309, 66496305, 58679096, 60487481, 66305850, 58675005, 66496319, 58644288, 58675020, 58654543, 58650452, 58664789, 66496344, 58681177, 58681187, 58654566, 58681197, 58681201, 58679154, 58681207, 66496379, 58681213, 60485509, 58644359, 58679181, 66496401, 60485522, 58681235, 58681239, 58681243, 58675100, 58664861, 58681248, 58650529, 66496418, 58679208, 58681260, 58681266, 58675123, 58644406, 66496439, 58806206, 58644417, 58687431, 66496460, 58644429, 58806224, 58675156, 58681303, 66496472, 58679258, 60485595, 58658780, 58806237, 58654687, 60485600, 58681315, 60485607, 58806248, 58654698, 58806251, 58681326, 58644464, 66496499, 58644468, 58806261, 58674769, 58654711, 60485628 ], cover: "", like_count: 79 } idhack:1 nupdated:1 keyUpdates:0 locks(micros) w:3574 687ms