Major - P3 Hello,
First of all I'm not looking for support on this, I'm not even sure if it's considered a bug but it seems like it's a bit dangerous.
I'm working on adding a new feature to mongodb and have been modifying the code for mongo S (not mongod/config server, which is the one I'm able to crash remotely).
Essentially I modified the mongo/s/shard_key_pattern.cpp to also accept "2dsphere" as a valid sharding key and then from the mongo shell called shardCollection with a 2dsphere key (index already configured). The config server promptly crashed with a core dump and the following backtrace:
2016-12-01T19:16:15.150+0000 I SHARDING [Balancer] ChunkManager loading chunks for wells_US.points sequenceNumber: 2 based on: (empty) 2016-12-01T19:16:15.151+0000 I SHARDING [Balancer] ChunkManager load took 0 ms and found version 1|0||584074beec62237f36f52c7e 2016-12-01T19:16:15.151+0000 I - [Balancer] Invariant failure !ci.key().isEmpty() src/mongo/s/config.cpp 296 2016-12-01T19:16:15.151+0000 I - [Balancer] ***aborting after invariant() failure 2016-12-01T19:16:15.165+0000 F - [Balancer] Got signal: 6 (Aborted). 0x56062610df71 0x56062610d069 0x56062610d54d 0x7fc771ae93e0 0x7fc771744428 0x7fc77174602a 0x5606253db006 0x560625fbde17 0x560625ff44de 0x560625c55903 0x560625c57310 0x560625c47045 0x560625c4dbe9 0x7fc7722ccc80 0x7fc771adf70a 0x7fc77181582d ----- BEGIN BACKTRACE ----- {"backtrace":[{"b":"560624C42000","o":"14CBF71","s":"_ZN5mongo15printStackTraceERSo"},{"b":"560624C42000","o":"14CB069"},{"b":"560624C42000","o":"14CB54D"},{"b":"7FC771AD8000","o":"113E0"},{"b":"7FC77170F000","o":"35428","s":"gsignal"},{"b":"7FC77170F000","o":"3702A","s":"abort"},{"b":"560624C42000","o":"799006","s":"_ZN5mongo17invariantOKFailedEPKcRKNS_6StatusES1_j"},{"b":"560624C42000","o":"137BE17","s":"_ZN5mongo8DBConfig15getChunkManagerEPNS_16OperationContextERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEbb"},{"b":"560624C42000","o":"13B24DE","s":"_ZN5mongo18ScopedChunkManager11getExistingEPNS_16OperationContextERKNS_15NamespaceStringE"},{"b":"560624C42000","o":"1013903","s":"_ZN5mongo32BalancerChunkSelectionPolicyImpl32_getSplitCandidatesForCollectionEPNS_16OperationContextERKNS_15NamespaceStringERKSt6vectorINS_17ClusterStatistics15ShardStatisticsESaIS8_EE"},{"b":"560624C42000","o":"1015310","s":"_ZN5mongo32BalancerChunkSelectionPolicyImpl19selectChunksToSplitEPNS_16OperationContextE"},{"b":"560624C42000","o":"1005045","s":"_ZN5mongo8Balancer17_enforceTagRangesEPNS_16OperationContextE"},{"b":"560624C42000","o":"100BBE9","s":"_ZN5mongo8Balancer11_mainThreadEv"},{"b":"7FC772214000","o":"B8C80"},{"b":"7FC771AD8000","o":"770A"},{"b":"7FC77170F000","o":"10682D","s":"clone"}],"processInfo":{ "mongodbVersion" : "3.4.0-rc5", "gitVersion" : "7df8fe1099135d137516f1670d2a0091ace63ca0", "compiledModules" : [], "uname" : { "sysname" : "Linux", "release" : "4.4.0-47-generic", "version" : "#68-Ubuntu SMP Wed Oct 26 19:39:52 UTC 2016", "machine" : "x86_64" }, "somap" : [ { "b" : "560624C42000", "elfType" : 3, "buildId" : "150938CE464DB3BAEAD640507516D58AEAE68656" }, { "b" : "7FFE89DFD000", "elfType" : 3, "buildId" : "263FD15D8149B82F2DB14A1E6C3351C2D9F4852C" }, { "b" : "7FC77279A000", "path" : "/lib/x86_64-linux-gnu/librt.so.1", "elfType" : 3, "buildId" : "4ABAAF20AC90D3E282D770F6A0C58A80BF16145A" }, { "b" : "7FC772596000", "path" : "/lib/x86_64-linux-gnu/libdl.so.2", "elfType" : 3, "buildId" : "09758D5225753BBF1FE3F66AADCCB6EC6F6E244B" }, { "b" : "7FC772214000", "path" : "/usr/lib/x86_64-linux-gnu/libstdc++.so.6", "elfType" : 3, "buildId" : "144E588F94CAFAFDBD0BD1499C74190F678DAD88" }, { "b" : "7FC771F0B000", "path" : "/lib/x86_64-linux-gnu/libm.so.6", "elfType" : 3, "buildId" : "9247F19167971267B6FADF4BA633290188A5483B" }, { "b" : "7FC771CF5000", "path" : "/lib/x86_64-linux-gnu/libgcc_s.so.1", "elfType" : 3, "buildId" : "68220AE2C65D65C1B6AAA12FA6765A6EC2F5F434" }, { "b" : "7FC771AD8000", "path" : "/lib/x86_64-linux-gnu/libpthread.so.0", "elfType" : 3, "buildId" : "3B58B373BD25A13045DCD3FCE540203DE330AC8E" }, { "b" : "7FC77170F000", "path" : "/lib/x86_64-linux-gnu/libc.so.6", "elfType" : 3, "buildId" : "A594A9C73A6067AB00A0F8DB78D665BE147ACDC1" }, { "b" : "7FC7729A2000", "path" : "/lib64/ld-linux-x86-64.so.2", "elfType" : 3, "buildId" : "F6DCBEE8DCAAE97C8BF7E73B56514E67118E6118" } ] }} mongod(_ZN5mongo15printStackTraceERSo+0x41) [0x56062610df71] mongod(+0x14CB069) [0x56062610d069] mongod(+0x14CB54D) [0x56062610d54d] libpthread.so.0(+0x113E0) [0x7fc771ae93e0] libc.so.6(gsignal+0x38) [0x7fc771744428] libc.so.6(abort+0x16A) [0x7fc77174602a] mongod(_ZN5mongo17invariantOKFailedEPKcRKNS_6StatusES1_j+0x0) [0x5606253db006] mongod(_ZN5mongo8DBConfig15getChunkManagerEPNS_16OperationContextERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEbb+0x1267) [0x560625fbde17] mongod(_ZN5mongo18ScopedChunkManager11getExistingEPNS_16OperationContextERKNS_15NamespaceStringE+0xAE) [0x560625ff44de] mongod(_ZN5mongo32BalancerChunkSelectionPolicyImpl32_getSplitCandidatesForCollectionEPNS_16OperationContextERKNS_15NamespaceStringERKSt6vectorINS_17ClusterStatistics15ShardStatisticsESaIS8_EE+0x53) [0x560625c55903] mongod(_ZN5mongo32BalancerChunkSelectionPolicyImpl19selectChunksToSplitEPNS_16OperationContextE+0x270) [0x560625c57310] mongod(_ZN5mongo8Balancer17_enforceTagRangesEPNS_16OperationContextE+0x55) [0x560625c47045] mongod(_ZN5mongo8Balancer11_mainThreadEv+0x11C9) [0x560625c4dbe9] libstdc++.so.6(+0xB8C80) [0x7fc7722ccc80] libpthread.so.0(+0x770A) [0x7fc771adf70a] libc.so.6(clone+0x6D) [0x7fc77181582d] ----- END BACKTRACE -----
Like I said, I'm not sure if this is considered a problem or not.
I can give more details if this looks relevant to the stability/security of the config server.