为什么Mongodb插入性能在一段时间后变得如此缓慢

我使用JavaAPI将1亿数据插入Mongodb（50%的列被索引，而不是由于业务逻辑而进行的批量插入）

表和索引结构：

db.gm_std_measurements.findOne();
{
    "_id" : ObjectId("530b6340e4b033fabd61fb99"),
    "fkDataSeriesId" : 421,
    "measDateUtc" : "2014-10-10 12:00:00",
    "measDateSite" : "2014-03-15 12:00:00",
    "project_id" : 379,
    "measvalue" : 597.516583008608,
    "refMeas" : false,
    "reliability" : 1
}

db.gm_std_measurements.getIndexes();
[
    {
        "v" : 1,
        "key" : {
            "_id" : 1
        },
        "ns" : "testdb.gm_std_measurements",
        "name" : "_id_"
    },
    {
        "v" : 1,
        "key" : {
            "fkDataSeriesId" : 1,
            "measDateUtc" : 1,
            "measDateSite" : 1,
            "project_id" : 1
        },
        "ns" : "testdb.gm_std_measurements",
        "name" : "default_mongodb_test_index"
    }
]

开始时，mongostat告诉我们速度非常好，每秒插入20-30k。但过了一段时间，性能下降得非常快，系统负载为5-10。原因可能是什么

正如所观察到的，很多时候，mongostat似乎被冻结（或者mongod被冻结），因为根本没有插入，并且“locked db”的跟踪数据也是0.0%，这正常吗

非常感谢

以下是mongostat的一些输出：

insert  query update delete getmore command flushes mapped  vsize    res faults    locked db idx miss %     qr|qw   ar|aw  netIn netOut  conn       time 
 39520     *0     *0     *0       0     1|0       0   160m   506m    67m      3 testdb:61.6%          0       0|0     0|1     9m     2k     4   15:58:26 
 36010     *0     *0     *0       0     1|0       0   160m   506m    83m      1 testdb:55.9%          0       0|0     0|0     8m     2k     4   15:58:27 
 33793     *0     *0     *0       0     1|0       0   288m   762m    92m      3 testdb:57.8%          0       0|0     0|0     7m     2k     4   15:58:28 
 32061     *0     *0     *0       0     1|0       0   288m   762m   113m      0 testdb:55.9%          0       0|0     0|0     7m     2k     4   15:58:29 
 32302     *0     *0     *0       0     1|0       0   288m   762m   110m      1 testdb:60.2%          0       0|0     0|1     7m     2k     4   15:58:30 
 31283     *0     *0     *0       0     1|0       0   288m   762m   138m      0 testdb:57.1%          0       0|0     0|1     7m     2k     4   15:58:31 
  1126     *0     *0     *0       0     1|0       0   544m  1.25g   367m      0  testdb:3.4%          0       0|0     0|1   258k     2k     4   15:58:55 
insert  query update delete getmore command flushes mapped  vsize    res faults    locked db idx miss %     qr|qw   ar|aw  netIn netOut  conn       time 
 18330     *0     *0     *0       0     1|0       0   544m  1.25g   369m      1 testdb:40.8%          0       0|0     0|1     4m     2k     4   15:58:56 
  4235     *0     *0     *0       0     1|0       0   544m  1.25g   395m      0  testdb:7.3%          0       0|0     0|1   974k     2k     4   15:58:57 
    *0     *0     *0     *0       0     1|0       0   544m  1.25g   395m      0  testdb:0.0%          0       0|0     0|1    62b     2k     4   15:58:58 
    *0     *0     *0     *0       0     1|0       0   544m  1.25g   395m      0  testdb:0.0%          0       0|0     0|1    62b     2k     4   15:58:59 
    *0     *0     *0     *0       0     1|0       0   544m  1.25g   395m      0  testdb:0.0%          0       0|0     0|1    62b     2k     4   15:59:00 
    *0     *0     *0     *0       0     1|0       0   544m  1.25g   395m      0  testdb:0.0%          0       0|0     0|1    62b     2k     4   15:59:01 
    *0     *0     *0     *0       0     1|0       0   544m  1.25g   395m      0  testdb:0.0%          0       0|0     0|1    62b     2k     4   15:59:02 
    *0     *0     *0     *0       0     1|0       0   544m  1.25g   395m      0  testdb:0.0%          0       0|0     0|1    62b     2k     4   15:59:04 
 20083     *0     *0     *0       0     1|0       0   544m  1.25g   378m      0      .:23.4%          0       0|0     0|1     4m     2k     4   15:59:05 
 28595     *0     *0     *0       0     1|0       0   544m  1.25g   404m      0 testdb:60.0%          0       0|0     0|0     6m     2k     4   15:59:06 
insert  query update delete getmore command flushes mapped  vsize    res faults    locked db idx miss %     qr|qw   ar|aw  netIn netOut  conn       time 
 26415     *0     *0     *0       0     1|0       0   544m  1.25g   381m      0 testdb:60.8%          0       0|0     0|1     6m     2k     4   15:59:07 
 27161     *0     *0     *0       0     1|0       0   544m  1.25g   411m      0 testdb:59.5%          0       0|0     0|1     6m     2k     4   15:59:08 
 25550     *0     *0     *0       0     1|0       0   544m  1.25g   397m      0 testdb:56.6%          0       0|0     0|1     5m     2k     4   15:59:09 
 26245     *0     *0     *0       0     1|0       0   544m  1.25g   429m      0 testdb:60.0%          0       0|0     0|1     6m     2k     4   15:59:10 
 27836     *0     *0     *0       0     1|0       0   544m  1.25g   444m      0 testdb:60.0%          0       0|0     0|1     6m     2k     4   15:59:11 
 27041     *0     *0     *0       0     1|0       0   544m  1.25g   422m      0 testdb:62.2%          0       0|0     0|1     6m     2k     4   15:59:12 
 26522     *0     *0     *0       0     1|0       0   544m  1.25g   463m      0 testdb:58.4%          0       0|0     0|1     6m     2k     4   15:59:13 
 27195     *0     *0     *0       0     1|0       0   544m  1.25g   475m      0 testdb:60.1%          0       0|0     0|1     6m     2k     4   15:59:14 
 25610     *0     *0     *0       0     1|0       0  1.03g  2.25g   500m      1 testdb:57.6%          0       0|0     0|1     5m     2k     4   15:59:15 
 25501     *0     *0     *0       0     1|0       0  1.03g  2.25g   474m      0 testdb:64.7%          0       0|0     0|1     5m     2k     4   15:59:16 
insert  query update delete getmore command flushes mapped  vsize    res faults    locked db idx miss %     qr|qw   ar|aw  netIn netOut  conn       time 
 27446     *0     *0     *0       0     1|0       0  1.03g  2.25g   489m      0 testdb:58.2%          0       0|1     0|1     6m     2k     4   15:59:17 
 27113     *0     *0     *0       0     1|0       0  1.03g  2.25g   515m      1 testdb:57.2%          0       0|1     0|1     6m     2k     4   15:59:18 
 25383     *0     *0     *0       0     1|0       0  1.03g  2.25g   524m      0 testdb:59.9%          0       0|0     0|1     5m     2k     4   15:59:19 
 27506     *0     *0     *0       0     1|0       0  1.03g  2.25g   546m      1 testdb:61.3%          0       0|0     0|1     6m     2k     4   15:59:20 
 14901      2     *0     *0       0     1|0       0  1.03g  2.25g   498m      0 testdb:32.8%          0       0|1     0|1     3m     2k     4   15:59:21 
  9026     *0     *0     *0       0     1|0       0  1.03g  2.25g   501m      0      .:62.5%          0       0|1     0|1     2m     2k     4   15:59:24 
 16834     *0     *0     *0       0     1|0       1  1.03g  2.25g   506m      0      .:73.9%          0       0|1     0|1     3m     3k     4   15:59:25 
 25975     *0     *0     *0       0     1|0       0  1.03g  2.25g   521m      0 testdb:60.8%          0       0|0     0|1     5m     2k     4   15:59:26 
 23389     *0     *0     *0       0     1|0       0  1.03g  2.25g   525m      0 testdb:58.4%          0       0|0     0|1     5m     2k     4   15:59:27 
 27226     *0     *0     *0       0     1|0       0  1.03g  2.25g   584m      0 testdb:55.0%          0       0|0     0|1     6m     2k     4   15:59:28 
insert  query update delete getmore command flushes mapped  vsize    res faults    locked db idx miss %     qr|qw   ar|aw  netIn netOut  conn       time 
 26362     *0     *0     *0       0     1|0       0  1.03g  2.25g   541m      0 testdb:56.3%          0       0|1     0|1     6m     2k     4   15:59:31 
  2658     *0     *0     *0       0     1|0       0  1.03g  2.25g   564m      0      .:64.2%          0       0|0     0|1   611k     3k     4   15:59:32 
    *0     *0     *0     *0       0     1|0       0  1.03g  2.25g   564m      0  testdb:0.0%          0       0|0     0|1    62b     2k     4   15:59:34 
    *0     *0     *0     *0       0     1|0       0  1.03g  2.25g   564m      0  testdb:0.0%          0       0|0     0|1    62b     2k     4   15:59:35 
    *0     *0     *0     *0       0     1|0       0  1.03g  2.25g   564m      0  testdb:0.0%          0       0|0     0|1    62b     2k     4   15:59:36 
  2777     *0     *0     *0       0     1|0       0  1.03g  2.25g   583m      0  testdb:4.8%          0       0|0     0|1   638k     2k     4   15:59:37 
    *0     *0     *0     *0       0     1|0       0  1.03g  2.25g   584m      0  testdb:0.0%          0       0|0     0|1    62b     2k     4   15:59:38 
    *0     *0     *0     *0       0     1|0       0  1.03g  2.25g   584m      0  testdb:0.0%          0       0|0     0|1    62b     2k     4   15:59:39 
    *0     *0     *0     *0       0     1|0       0  1.03g  2.25g   584m      0  testdb:0.0%          0       0|0     0|1    62b     2k     4   15:59:40 
    *0     *0     *0     *0       0     1|0       0  1.03g  2.25g   584m      0  testdb:0.0%          0       0|0     0|1    62b     2k     4   15:59:41 
insert  query update delete getmore command flushes mapped  vsize    res faults    locked db idx miss %     qr|qw   ar|aw  netIn netOut  conn       time 
    *0     *0     *0     *0       0     1|0       0  1.03g  2.25g   584m      0  testdb:0.0%          0       0|0     0|1    62b     2k     4   15:59:42 
 19823     *0     *0     *0       0     1|0       0  1.03g  2.25g   549m      0 testdb:57.8%          0       0|1     0|1     4m     2k     4   15:59:43 
 25267     *0     *0     *0       0     1|0       0  1.03g  2.25g   561m      0 testdb:60.4%          0       0|0     0|1     5m     2k     4   15:59:44 
 26489     *0     *0     *0       0     1|0       0  1.03g  2.25g   601m      0 testdb:58.8%          0       0|0     0|1     6m     2k     4   15:59:45 
 26516     *0     *0     *0       0     1|0       0  1.03g  2.25g   604m      0 testdb:58.4%          0       0|0     0|1     1m     2k     4   16:00:26 
   *0     *0     *0     *0       0     1|0       0  2.03g  4.25g   868m      0  testdb:0.0%          0       0|0     0|1    62b     2k     4   16:00:27 
   *0     *0     *0     *0       0     1|0       0  2.03g  4.25g   868m      0  testdb:0.0%          0       0|0     0|1    62b     2k     4   16:00:33 
 2775     *0     *0     *0       0     1|0       0  2.03g  4.25g   845m      0  testdb:0.8%          0       0|1     0|1   638k     3k     4   16:00:34 
 3886     *0     *0     *0       0     1|0       0  2.03g  4.25g   879m      0      .:30.5%          0       0|0     0|1   893k     2k     4   16:00:35

---

您可以尝试删除索引，然后执行插入，插入完成后，您可以创建索引。我认为这将是一个整体更快的场景

您还可以在后台重新创建索引

db.collection.ensureIndex( { a: 1 }, { background: true } )

---

如果您想继续查询，但这会使索引创建变慢

“原因可能是什么”-很可能是索引。@SergioTulentsev，您的意思是在索引写入/更新期间，插入率将为0？插入文档时，所有索引都会更新。索引越多（越大），写入速度就越慢。我已经更新了我的表和索引结构。有些情况下，插入率是0，它会持续相当长的一段时间，并且出现的频率越来越高。如果它是索引更新，我想只有插入速度会减慢，但应该是稳定的。在我的情况下，似乎有别的东西阻止了mongod。。。