Major - P3 Just documenting this for our Project Manager, no symptoms seen in RC8 nor in RC9-pre.
mongod running wiredTiger becomes unresponsive, perhaps just sufficiently slow so as to appear unresponsive. Multiple write operations appear "stuck" with many threads repeatedly waiting on pthread_cond_timedwait related to WT cache.
attached to the Linux process with gdb and found it is spawning threads rapidly, with many threads looking for a condition variable, apparently a WT cache wait.
(gdb) info threads 15 Thread 0x7fdd10f36700 (LWP 6554) 0x00007fdd17d174b5 in sigwait () from /lib64/libpthread.so.0 14 Thread 0x7fdd10535700 (LWP 6555) 0x00007fdd17d1398e in pthread_cond_timedwait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0 13 Thread 0x7fdd0fb34700 (LWP 6556) 0x00007fdd17d1398e in pthread_cond_timedwait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0 12 Thread 0x7fdd0f133700 (LWP 6557) 0x00007fdd17d1398e in pthread_cond_timedwait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0 11 Thread 0x7fdd0e732700 (LWP 6558) 0x00007fdd17d1398e in pthread_cond_timedwait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0 10 Thread 0x7fdd0dd31700 (LWP 6559) 0x00007fdd17d1398e in pthread_cond_timedwait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0 9 Thread 0x7fdd0d330700 (LWP 6560) 0x00007fdd17d135bc in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0 8 Thread 0x7fdd0c92f700 (LWP 6561) 0x00007fdd17d1398e in pthread_cond_timedwait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0 7 Thread 0x7fdd0bf2e700 (LWP 6562) 0x00007fdd17d1398e in pthread_cond_timedwait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0 6 Thread 0x7fdd0b52d700 (LWP 6563) 0x00007fdd17d1398e in pthread_cond_timedwait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0 5 Thread 0x7fdd0ab2c700 (LWP 6564) 0x00007fdd17d1398e in pthread_cond_timedwait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0 4 Thread 0x7fdd0a02a700 (LWP 6592) 0x00007fdd17d1398e in pthread_cond_timedwait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0 3 Thread 0x7fdd09821700 (LWP 6693) 0x000000000131c582 in ?? () 2 Thread 0x7fdd08e20700 (LWP 6694) 0x000000000131c56b in ?? () * 1 Thread 0x7fdd18138b60 (LWP 6553) 0x00007fdd16ea95d3 in select () from /lib64/libc.so.6 (gdb) bt #0 0x00007fdd17d1398e in pthread_cond_timedwait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0 #1 0x000000000133468f in __wt_cond_wait () #2 0x000000000131c80c in __wt_cache_wait () #3 0x00000000012cd8ca in __wt_btcur_search () #4 0x00000000013078f3 in ?? () #5 0x0000000000d55b31 in mongo::WiredTigerRecordStore::findRecord(mongo::OperationContext*, mongo::RecordId const&, mongo::RecordData*) const () #6 0x0000000000cc9df1 in mongo::KVCatalog::_findEntry(mongo::OperationContext*, mongo::StringData const&, mongo::RecordId*) const () #7 0x0000000000cca050 in mongo::KVCatalog::getMetaData(mongo::OperationContext*, mongo::StringData const&) () #8 0x0000000000cceba5 in mongo::KVCollectionCatalogEntry::_getMetaData(mongo::OperationContext*) const () #9 0x0000000000cae9c6 in mongo::BSONCollectionCatalogEntry::getTotalIndexCount(mongo::OperationContext*) const () #10 0x00000000009bc0f1 in mongo::CmdDrop::run(mongo::OperationContext*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, mongo::BSONObj&, int, std::basic_string<char, std::char_traits<char>, std::allocator<char> >&, mongo::BSONObjBuilder&, bool) () #11 0x00000000009b71a4 in mongo::_execCommand(mongo::OperationContext*, mongo::Command*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, mongo::BSONObj&, int, std::basic_string<char, std::char_traits<char>, std::allocator<char> >&, mongo::BSONObjBuilder&, bool) () #12 0x00000000009b80e3 in mongo::Command::execCommand(mongo::OperationContext*, mongo::Command*, int, char const*, mongo::BSONObj&, mongo::BSONObjBuilder&, bool) () #13 0x00000000009b8cdb in mongo::_runCommands(mongo::OperationContext*, char const*, mongo::BSONObj&, mongo::_BufBuilder<mongo::TrivialAllocator>&, mongo::BSONObjBuilder&, bool, int) () #14 0x0000000000b87f95 in mongo::runQuery(mongo::OperationContext*, mongo::Message&, mongo::QueryMessage&, mongo::NamespaceString const&, mongo::CurOp&, mongo::Message&, bool) () #15 0x0000000000a99f88 in mongo::assembleResponse(mongo::OperationContext*, mongo::Message&, mongo::DbResponse&, mongo::HostAndPort const&, bool) () #16 0x00000000007e6730 in mongo::MyMessageHandler::process(mongo::Message&, mongo::AbstractMessagingPort*, mongo::LastError*) () #17 0x0000000000ef8aab in mongo::PortMessageServer::handleIncomingMsg(void*) () #18 0x00007fdd17d0f9d1 in start_thread () from /lib64/libpthread.so.0 ---Type <return> to continue, or q <return> to quit--- #19 0x00007fdd16eb0b5d in clone () from /lib64/libc.so.6