使用benchRun（）使用this测试在mongodb中进行性能测量。当x大于128时，benchRun崩溃了。
以下是stacktrace：
for ( var x = 1; x <= 256; x *= 2) { res = benchRun( { parallel : x , seconds : 5 , ops : ops } ); print( "threads: " + x + "\t queries/sec: " + res.query ); }
threads: 1 queries/sec: 9710.149419988862
threads: 2 queries/sec: 20123.612706850294
threads: 4 queries/sec: 20104.887937887142
threads: 8 queries/sec: 20021.93510847081
threads: 16 queries/sec: 20047.279206425876
threads: 32 queries/sec: 22452.635848061327
threads: 64 queries/sec: 22909.73264053509
threads: 128 queries/sec: 22919.056958070505
2015-08-04T11:48:21.733+0000 I - Invariant failure bsonTemplateEvaluator.setId(_id) == BsonTemplateEvaluator::StatusSuccess src/mongo/shell/bench.cpp 349
2015-08-04T11:48:21.735+0000 I CONTROL
0x80c9e9 0x7c1871 0x7a8902 0x77fc83 0x7808fd 0x858c54 0x7fd9c1794182 0x7fd9c089547d
----- BEGIN BACKTRACE -----
{"backtrace":[{"b":"400000","o":"40C9E9"},{"b":"400000","o":"3C1871"},{"b":"400000","o":"3A8902"},{"b":"400000","o":"37FC83"},{"b":"400000","o":"3808FD"},{"b":"400000","o":"458C54"},{"b":"7FD9C178C000","o":"8182"},{"b":"7FD9C079B000","o":"FA47D"}],"processInfo":{ "mongodbVersion" : "3.0.4", "gitVersion" : "nogitversion", "uname" : { "sysname" : "Linux", "release" : "3.13.0-46-generic", "version" : "#77-Ubuntu SMP Mon Mar 2 18:23:39 UTC 2015", "machine" : "x86_64" }, "somap" : [ { "elfType" : 2, "b" : "400000", "buildId" : "281BC2D7C110F599E334B1B8DCCFA7ED04F4DD89" }, { "b" : "7FFF61E5B000", "elfType" : 3, "buildId" : "88E7559031E488BC215236F4181BD1FAF9A458F0" }, { "b" : "7FD9C178C000", "path" : "/lib/x86_64-linux-gnu/libpthread.so.0", "elfType" : 3, "buildId" : "9318E8AF0BFBE444731BB0461202EF57F7C39542" }, { "b" : "7FD9C1584000", "path" : "/lib/x86_64-linux-gnu/librt.so.1", "elfType" : 3, "buildId" : "92FCF41EFE012D6186E31A59AD05BDBB487769AB" }, { "b" : "7FD9C1380000", "path" : "/lib/x86_64-linux-gnu/libdl.so.2", "elfType" : 3, "buildId" : "C1AE4CB7195D337A77A3C689051DABAA3980CA0C" }, { "b" : "7FD9C107C000", "path" : "/usr/lib/x86_64-linux-gnu/libstdc++.so.6", "elfType" : 3, "buildId" : "19EFDDAB11B3BF5C71570078C59F91CF6592CE9E" }, { "b" : "7FD9C0D76000", "path" : "/lib/x86_64-linux-gnu/libm.so.6", "elfType" : 3, "buildId" : "1D76B71E905CB867B27CEF230FCB20F01A3178F5" }, { "b" : "7FD9C0B60000", "path" : "/lib/x86_64-linux-gnu/libgcc_s.so.1", "elfType" : 3, "buildId" : "8D0AA71411580EE6C08809695C3984769F25725B" }, { "b" : "7FD9C079B000", "path" : "/lib/x86_64-linux-gnu/libc.so.6", "elfType" : 3, "buildId" : "30C94DC66A1FE95180C3D68D2B89E576D5AE213C" }, { "b" : "7FD9C19AA000", "path" : "/lib64/ld-linux-x86-64.so.2", "elfType" : 3, "buildId" : "9F00581AB3C73E3AEA35995A0C50D24D59A01D47" } ] }}
mongo(_ZN5mongo15printStackTraceERSo+0x29) [0x80c9e9]
mongo(_ZN5mongo10logContextEPKc+0xE1) [0x7c1871]
mongo(_ZN5mongo15invariantFailedEPKcS1_j+0xB2) [0x7a8902]
mongo(_ZN5mongo14BenchRunWorker24generateLoadOnConnectionEPNS_12DBClientBaseE+0x5EF3) [0x77fc83]
mongo(_ZN5mongo14BenchRunWorker3runEv+0xED) [0x7808fd]
mongo(+0x458C54) [0x858c54]
libpthread.so.0(+0x8182) [0x7fd9c1794182]
libc.so.6(clone+0x6D) [0x7fd9c089547d]
----- END BACKTRACE -----
2015-08-04T11:48:21.737+0000 I -
***aborting after invariant() failure
2015-08-04T11:48:21.736+0000 I - Invariant failure bsonTemplateEvaluator.setId(_id) == BsonTemplateEvaluator::StatusSuccess src/mongo/shell/bench.cpp 349
2015-08-04T11:48:21.736+0000 I - Invariant failure bsonTemplateEvaluator.setId(_id) == BsonTemplateEvaluator::StatusSuccess src/mongo/shell/bench.cpp 349
2015-08-04T11:48:21.736+0000 I - Invariant failure bsonTemplateEvaluator.setId(_id) == BsonTemplateEvaluator::StatusSuccess src/mongo/shell/bench.cpp 349
2015-08-04T11:48:21.736+0000 I - Invariant failure bsonTemplateEvaluator.setId(_id) == BsonTemplateEvaluator::StatusSuccess src/mongo/shell/bench.cpp 349
2015-08-04T11:48:21.736+0000 I - Invariant failure bsonTemplateEvaluator.setId(_id) == BsonTemplateEvaluator::StatusSuccess src/mongo/shell/bench.cpp 349
2015-08-04T11:48:21.736+0000 I - Invariant failure bsonTemplateEvaluator.setId(_id) == BsonTemplateEvaluator::StatusSuccess src/mongo/shell/bench.cpp 349
2015-08-04T11:48:21.736+0000 I - Invariant failure bsonTemplateEvaluator.setId(_id) == BsonTemplateEvaluator::StatusSuccess src/mongo/shell/bench.cpp 349
2015-08-04T11:48:21.736+0000 I - Invariant failure bsonTemplateEvaluator.setId(_id) == BsonTemplateEvaluator::StatusSuccess src/mongo/shell/bench.cpp 349
2015-08-04T11:48:21.736+0000 I - Invariant failure bsonTemplateEvaluator.setId(_id) == BsonTemplateEvaluator::StatusSuccess src/mongo/shell/bench.cpp 349
除了来自客户端的连接结束消息之外，在日志中找不到任何不正常的内容。连接总数约为150.这个问题的可能原因是什么？
Mongodb版本：2.6.7,3.0.4