我最近一直在研究可用于 .NET 的 nosql 选项,并且 MongoDB 在可用性和支持方面明显成为赢家,所以今晚我决定尝试一下。我从 mongodb 站点下载了版本 1.2.4(Windows x64 二进制)并使用以下选项运行它:
C:\mongodb\bin>mkdir data
C:\mongodb\bin>mongod -dbpath ./data --cpu --quiet
然后我加载了最新的 mongodb-csharp 驱动程序http://github.com/samus/mongodb-csharp http://github.com/samus/mongodb-csharp并立即运行基准程序。在听说 MongoDB 有多“快得惊人”之后,我对糟糕的基准性能感到相当震惊。
Starting Tests
encode (small).........................................320000 00:00:00.0156250
encode (medium)........................................80000 00:00:00.0625000
encode (large).........................................1818 00:00:02.7500000
decode (small).........................................320000 00:00:00.0156250
decode (medium)........................................160000 00:00:00.0312500
decode (large).........................................2370 00:00:02.1093750
insert (small, no index)...............................2176 00:00:02.2968750
insert (medium, no index)..............................2269 00:00:02.2031250
insert (large, no index)...............................778 00:00:06.4218750
insert (small, indexed)................................2051 00:00:02.4375000
insert (medium, indexed)...............................2133 00:00:02.3437500
insert (large, indexed)................................835 00:00:05.9843750
batch insert (small, no index).........................53333 00:00:00.0937500
batch insert (medium, no index)........................26666 00:00:00.1875000
batch insert (large, no index).........................1114 00:00:04.4843750
find_one (small, no index).............................350 00:00:14.2812500
find_one (medium, no index)............................204 00:00:24.4687500
find_one (large, no index).............................135 00:00:37.0156250
find_one (small, indexed)..............................352 00:00:14.1718750
find_one (medium, indexed).............................184 00:00:27.0937500
find_one (large, indexed)..............................128 00:00:38.9062500
find (small, no index).................................516 00:00:09.6718750
find (medium, no index)................................316 00:00:15.7812500
find (large, no index).................................216 00:00:23.0468750
find (small, indexed)..................................532 00:00:09.3906250
find (medium, indexed).................................346 00:00:14.4375000
find (large, indexed)..................................212 00:00:23.5468750
find range (small, indexed)............................440 00:00:11.3593750
find range (medium, indexed)...........................294 00:00:16.9531250
find range (large, indexed)............................199 00:00:25.0625000
Press any key to continue...
首先,我可以从 SQL Server Express 获得更好的非批量插入性能。然而,真正令我震惊的是 find_nnnn 查询的缓慢性能。为什么从 MongoDB 检索数据这么慢?我缺少什么?
Edit:这一切都在本地计算机上进行,没有网络延迟或其他任何情况。在整个测试运行期间,MongoDB 的 CPU 使用率约为 75%。另外,我对基准程序进行了跟踪,并确认 50% 的 CPU 时间用于等待 MongoDB 返回数据,因此这不是 C# 驱动程序的性能问题。