Major - P3 Problem Statement/Rationale
When client (mongosh or mongo shell) is properly ending connection to MongoDB server (using command exit) the "HostUnreachable" exception is thrown and logged together with huge backtrace information. This got worse - more logging - with version 5.0 and 6.0 (compared to 4.4.2).
The problem seems to be general, because the same behavior is with mongosh and mongo shell.
Expected Results
On proper disconnect (no timeout, no network issues or any other issues) I would expect just simple message "Client disconnected" the same way it is when client connects (just message "Connection accepted").
Actual Results
Exception is thrown (why should be exception thrown on proper disconnect?) and huge amount of log (backtrace) information is generated - e.g.
{"t":{"$date":"2022-08-11T12:23:13.065+02:00"},"s":"W", "c":"-", "id":23075, "ctx":"conn5","msg":"DBException thrown","attr":{"error":{"code":6,"codeName":"HostUnreachable","errmsg":"Connection closed by peer"}}}
{"t":{"$date":"2022-08-11T12:23:13.066+02:00"},"s":"W", "c":"-", "id":23075, "ctx":"conn2","msg":"DBException thrown","attr":{"error":{"code":6,"codeName":"HostUnreachable","errmsg":"Connection reset by peer"}}}
{"t":{"$date":"2022-08-11T12:23:13.066+02:00"},"s":"W", "c":"-", "id":23075, "ctx":"conn3","msg":"DBException thrown","attr":{"error":{"code":6,"codeName":"HostUnreachable","errmsg":"Connection closed by peer"}}}
{"t":{"$date":"2022-08-11T12:23:13.066+02:00"},"s":"W", "c":"-", "id":23075, "ctx":"conn4","msg":"DBException thrown","attr":{"error":{"code":6,"codeName":"HostUnreachable","errmsg":"Connection closed by peer"}}}
{"t":{"$date":"2022-08-11T12:23:13.204+02:00"},"s":"I", "c":"CONTROL", "id":31380, "ctx":"conn5","msg":"BACKTRACE","attr":{"bt":{"backtrace":[{"a":"7FF68FDF0963","module":"mongod.exe","file":".../src/mongo/util/stacktrace_windows.cpp","line":321,"s":"mongo::`anonymous namespace'::printWindowsStackTraceImpl","s+":"43"},{"a":"7FF68FDFD86B","module":"mongod.exe","file":".../src/mongo/util/assert_util.cpp","line":86,"s":"mongo::DBException::traceIfNeeded","s+":"1CB"},{"a":"7FF68FE655F1","module":"mongod.exe","file":".../src/mongo/util/assert_util.h","line":152,"s":"mongo::AssertionException::AssertionException","s+":"41"},{"a":"7FF68FE50360","module":"mongod.exe","file":".../src/mongo/util/assert_util.h","line":183,"s":"mongo::error_details::ExceptionForImpl<6,mongo::ExceptionForCat<0>,mongo::ExceptionForCat<14> >::ExceptionForImpl<6,mongo::ExceptionForCat<0>,mongo::ExceptionForCat<14> >","s+":"40"},{"a":"7FF68FE6A46F","module":"mongod.exe","file":"Z:/data/mci/bf6ffa5cf5d9d0de72c13c6788749135/src/build/opt/mongo/base/error_codes.cpp","line":2230,"s":"mongo::error_details::throwExceptionForStatus","s+":"DF"},{"a":"7FF68FDFDA14","module":"mongod.exe","file":".../src/mongo/util/assert_util.cpp","line":260,"s":"mongo::uassertedWithLocation","s+":"184"},{"a":"7FF68E56E6D1","module":"mongod.exe","file":".../src/mongo/transport/service_state_machine.cpp","line":394,"s":"mongo::transport::ServiceStateMachine::Impl::sourceCallback","s+":"4F1"},{"a":"7FF68E5691FD","module":"mongod.exe","file":".../src/mongo/util/future_impl.h","line":250,"s":"mongo::future_details::call<<lambda_adee3533ad9aaebd514c253f861c99b3> &,mongo::StatusWith<mongo::Message> >","s+":"AD"},{"a":"7FF68E56AD46","module":"mongod.exe","file":".../src/mongo/util/future_impl.h","line":986,"s":"<lambda_71c7af3a1314ac8fa87ef8ca0e57d022>::operator()","s+":"56"},{"a":"7FF68E5698B0","module":"mongod.exe","file":".../src/mongo/util/future_impl.h","line":1193,"s":"mongo::future_details::FutureImpl<mongo::Message>::generalImpl<<lambda_3511eed2ba74e987471aa1dba7886515>,<lambda_71c7af3a1314ac8fa87ef8ca0e57d022>,<lambda_7bb8db0db7b00eed4c9c32637ebc8440> >","s+":"80"},{"a":"7FF68E56E847","module":"mongod.exe","file":".../src/mongo/transport/service_state_machine.cpp","line":321,"s":"mongo::transport::ServiceStateMachine::Impl::sourceMessage","s+":"157"},{"a":"7FF68E569FF6","module":"mongod.exe","file":".../src/mongo/util/future.h","line":1211,"s":"mongo::makeReadyFutureWith<<lambda_abaa6d044ac34b6d286cfbc6dd2101a2>,0>","s+":"36"},{"a":"7FF68E56EAA2","module":"mongod.exe","file":".../src/mongo/transport/service_state_machine.cpp","line":570,"s":"mongo::transport::ServiceStateMachine::Impl::startNewLoop","s+":"62"},{"a":"7FF68E56B9BA","module":"mongod.exe","file":".../src/mongo/util/functional.h","line":154,"s":"`mongo::unique_function<void __cdecl(mongo::Status)>::makeImpl<<lambda_c6b349ee357260a796ff8e9aa04c91e0> >'::`2'::SpecificImpl::call","s+":"6A"},{"a":"7FF68FAD8747","module":"mongod.exe","file":".../src/mongo/util/functional.h","line":154,"s":"`mongo::unique_function<void __cdecl(mongo::Status)>::makeImpl<<lambda_f6fe401c5262fec9b8f8213c1ce091a0> >'::`2'::SpecificImpl::call","s+":"47"},{"a":"7FF68FAD86CB","module":"mongod.exe","file":".../src/mongo/util/functional.h","line":154,"s":"`mongo::unique_function<void __cdecl(void)>::makeImpl<<lambda_00027e990a0ecbb312a62eb8601f0a9b> >'::`2'::SpecificImpl::call","s+":"2B"},{"a":"7FF68FAD80D9","module":"mongod.exe","file":".../src/mongo/transport/service_executor_synchronous.cpp","line":132,"s":"<lambda_f9db7de3fc63d9ea9f1724897a3de362>::operator()","s+":"D9"},{"a":"7FF68FAD7132","module":"mongod.exe","file":"C:/Program Files (x86)/Microsoft Visual Studio/2019/Professional/VC/Tools/MSVC/14.29.30133/include/thread","line":55,"s":"std::thread::_Invoke<std::tuple<<lambda_8cebf4d190f9c1ee7cff12dbc09aadbe> >,0>","s+":"32"},{"a":"7FFB24251BB2","module":"ucrtbase.dll","s":"configthreadlocale","s+":"92"},{"a":"7FFB24657034","module":"KERNEL32.DLL","s":"BaseThreadInitThunk","s+":"14"}]}}}
{"t":{"$date":"2022-08-11T12:23:13.204+02:00"},"s":"I", "c":"CONTROL", "id":31445, "ctx":"conn5","msg":"Frame","attr":{"frame":{"a":"7FF68FDF0963","module":"mongod.exe","file":".../src/mongo/util/stacktrace_windows.cpp","line":321,"s":"mongo::`anonymous namespace'::printWindowsStackTraceImpl","s+":"43"}}}
{"t":{"$date":"2022-08-11T12:23:13.204+02:00"},"s":"I", "c":"CONTROL", "id":31445, "ctx":"conn5","msg":"Frame","attr":{"frame":{"a":"7FF68FDFD86B","module":"mongod.exe","file":".../src/mongo/util/assert_util.cpp","line":86,"s":"mongo::DBException::traceIfNeeded","s+":"1CB"}}}
{"t":{"$date":"2022-08-11T12:23:13.204+02:00"},"s":"I", "c":"CONTROL", "id":31445, "ctx":"conn5","msg":"Frame","attr":{"frame":{"a":"7FF68FE655F1","module":"mongod.exe","file":".../src/mongo/util/assert_util.h","line":152,"s":"mongo::AssertionException::AssertionException","s+":"41"}}}
{"t":{"$date":"2022-08-11T12:23:13.204+02:00"},"s":"I", "c":"CONTROL", "id":31445, "ctx":"conn5","msg":"Frame","attr":{"frame":{"a":"7FF68FE50360","module":"mongod.exe","file":".../src/mongo/util/assert_util.h","line":183,"s":"mongo::error_details::ExceptionForImpl<6,mongo::ExceptionForCat<0>,mongo::ExceptionForCat<14> >::ExceptionForImpl<6,mongo::ExceptionForCat<0>,mongo::ExceptionForCat<14> >","s+":"40"}}}
{"t":{"$date":"2022-08-11T12:23:13.204+02:00"},"s":"I", "c":"CONTROL", "id":31445, "ctx":"conn5","msg":"Frame","attr":{"frame":{"a":"7FF68FE6A46F","module":"mongod.exe","file":"Z:/data/mci/bf6ffa5cf5d9d0de72c13c6788749135/src/build/opt/mongo/base/error_codes.cpp","line":2230,"s":"mongo::error_details::throwExceptionForStatus","s+":"DF"}}}
{"t":{"$date":"2022-08-11T12:23:13.204+02:00"},"s":"I", "c":"CONTROL", "id":31445, "ctx":"conn5","msg":"Frame","attr":{"frame":{"a":"7FF68FDFDA14","module":"mongod.exe","file":".../src/mongo/util/assert_util.cpp","line":260,"s":"mongo::uassertedWithLocation","s+":"184"}}}
{"t":{"$date":"2022-08-11T12:23:13.204+02:00"},"s":"I", "c":"CONTROL", "id":31445, "ctx":"conn5","msg":"Frame","attr":{"frame":{"a":"7FF68E56E6D1","module":"mongod.exe","file":".../src/mongo/transport/service_state_machine.cpp","line":394,"s":"mongo::transport::ServiceStateMachine::Impl::sourceCallback","s+":"4F1"}}}
{"t":{"$date":"2022-08-11T12:23:13.204+02:00"},"s":"I", "c":"CONTROL", "id":31445, "ctx":"conn5","msg":"Frame","attr":{"frame":{"a":"7FF68E5691FD","module":"mongod.exe","file":".../src/mongo/util/future_impl.h","line":250,"s":"mongo::future_details::call<<lambda_adee3533ad9aaebd514c253f861c99b3> &,mongo::StatusWith<mongo::Message> >","s+":"AD"}}}
{"t":{"$date":"2022-08-11T12:23:13.204+02:00"},"s":"I", "c":"CONTROL", "id":31445, "ctx":"conn5","msg":"Frame","attr":{"frame":{"a":"7FF68E56AD46","module":"mongod.exe","file":".../src/mongo/util/future_impl.h","line":986,"s":"<lambda_71c7af3a1314ac8fa87ef8ca0e57d022>::operator()","s+":"56"}}}
{"t":{"$date":"2022-08-11T12:23:13.204+02:00"},"s":"I", "c":"CONTROL", "id":31445, "ctx":"conn5","msg":"Frame","attr":{"frame":{"a":"7FF68E5698B0","module":"mongod.exe","file":".../src/mongo/util/future_impl.h","line":1193,"s":"mongo::future_details::FutureImpl<mongo::Message>::generalImpl<<lambda_3511eed2ba74e987471aa1dba7886515>,<lambda_71c7af3a1314ac8fa87ef8ca0e57d022>,<lambda_7bb8db0db7b00eed4c9c32637ebc8440> >","s+":"80"}}}
{"t":{"$date":"2022-08-11T12:23:13.204+02:00"},"s":"I", "c":"CONTROL", "id":31445, "ctx":"conn5","msg":"Frame","attr":{"frame":{"a":"7FF68E56E847","module":"mongod.exe","file":".../src/mongo/transport/service_state_machine.cpp","line":321,"s":"mongo::transport::ServiceStateMachine::Impl::sourceMessage","s+":"157"}}}
{"t":{"$date":"2022-08-11T12:23:13.205+02:00"},"s":"I", "c":"CONTROL", "id":31445, "ctx":"conn5","msg":"Frame","attr":{"frame":{"a":"7FF68E569FF6","module":"mongod.exe","file":".../src/mongo/util/future.h","line":1211,"s":"mongo::makeReadyFutureWith<<lambda_abaa6d044ac34b6d286cfbc6dd2101a2>,0>","s+":"36"}}}
{"t":{"$date":"2022-08-11T12:23:13.205+02:00"},"s":"I", "c":"CONTROL", "id":31445, "ctx":"conn5","msg":"Frame","attr":{"frame":{"a":"7FF68E56EAA2","module":"mongod.exe","file":".../src/mongo/transport/service_state_machine.cpp","line":570,"s":"mongo::transport::ServiceStateMachine::Impl::startNewLoop","s+":"62"}}}
{"t":{"$date":"2022-08-11T12:23:13.205+02:00"},"s":"I", "c":"CONTROL", "id":31445, "ctx":"conn5","msg":"Frame","attr":{"frame":{"a":"7FF68E56B9BA","module":"mongod.exe","file":".../src/mongo/util/functional.h","line":154,"s":"`mongo::unique_function<void __cdecl(mongo::Status)>::makeImpl<<lambda_c6b349ee357260a796ff8e9aa04c91e0> >'::`2'::SpecificImpl::call","s+":"6A"}}}
{"t":{"$date":"2022-08-11T12:23:13.205+02:00"},"s":"I", "c":"CONTROL", "id":31445, "ctx":"conn5","msg":"Frame","attr":{"frame":{"a":"7FF68FAD8747","module":"mongod.exe","file":".../src/mongo/util/functional.h","line":154,"s":"`mongo::unique_function<void __cdecl(mongo::Status)>::makeImpl<<lambda_f6fe401c5262fec9b8f8213c1ce091a0> >'::`2'::SpecificImpl::call","s+":"47"}}}
{"t":{"$date":"2022-08-11T12:23:13.205+02:00"},"s":"I", "c":"CONTROL", "id":31445, "ctx":"conn5","msg":"Frame","attr":{"frame":{"a":"7FF68FAD86CB","module":"mongod.exe","file":".../src/mongo/util/functional.h","line":154,"s":"`mongo::unique_function<void __cdecl(void)>::makeImpl<<lambda_00027e990a0ecbb312a62eb8601f0a9b> >'::`2'::SpecificImpl::call","s+":"2B"}}}
{"t":{"$date":"2022-08-11T12:23:13.205+02:00"},"s":"I", "c":"CONTROL", "id":31445, "ctx":"conn5","msg":"Frame","attr":{"frame":{"a":"7FF68FAD80D9","module":"mongod.exe","file":".../src/mongo/transport/service_executor_synchronous.cpp","line":132,"s":"<lambda_f9db7de3fc63d9ea9f1724897a3de362>::operator()","s+":"D9"}}}
{"t":{"$date":"2022-08-11T12:23:13.205+02:00"},"s":"I", "c":"CONTROL", "id":31445, "ctx":"conn5","msg":"Frame","attr":{"frame":{"a":"7FF68FAD7132","module":"mongod.exe","file":"C:/Program Files (x86)/Microsoft Visual Studio/2019/Professional/VC/Tools/MSVC/14.29.30133/include/thread","line":55,"s":"std::thread::_Invoke<std::tuple<<lambda_8cebf4d190f9c1ee7cff12dbc09aadbe> >,0>","s+":"32"}}}
{"t":{"$date":"2022-08-11T12:23:13.205+02:00"},"s":"I", "c":"CONTROL", "id":31445, "ctx":"conn5","msg":"Frame","attr":{"frame":{"a":"7FFB24251BB2","module":"ucrtbase.dll","s":"configthreadlocale","s+":"92"}}}
{"t":{"$date":"2022-08-11T12:23:13.205+02:00"},"s":"I", "c":"CONTROL", "id":31445, "ctx":"conn5","msg":"Frame","attr":{"frame":{"a":"7FFB24657034","module":"KERNEL32.DLL","s":"BaseThreadInitThunk","s+":"14"}}}
{"t":{"$date":"2022-08-11T12:23:13.205+02:00"},"s":"W", "c":"-", "id":23075, "ctx":"conn5","msg":"DBException thrown","attr":{"error":{"code":6,"codeName":"HostUnreachable","errmsg":"Connection closed by peer"}}}
Running Mongo 5.0 and 6.0 and verbose level 0 and going through all the steps in "Steps to Reproduce" it generates 245 kB log file. Just client connecting and immediately disconnecting, no other actions.
This is a problem, because when there are some mongosh scripts running (e.g. zabbix monitoring) then Mongo creates a huge log file just overnight filled with backtraces of those 'disconnect exceptions'.
Additional Notes
All following files are just logs from "steps to reproduce" - connecting and disconnecting to MongoDB. The Mongo server started on version 4.4.2 and then was upgraded to 5.0 and 6.0.
Files attached:
MongoDBLog4.4.2.mongosh.txt (64kB) - connecting with mongosh to MongoDB 4.4.2
MongoDBLog5.0.mongosh.txt (258kB)- the same, just connecting to MongoDB 5.0.10
MongoDBLog6.0.mongosh.txt (245kB)- the same, just connecting to MongoDB 6.0
MongoDBLog6.0.MongoShell.txt (143kB)- connecting with mongo shell to MongoDB 6.0