(gdb) t a a bt

Thread 11 (Thread 0x7f837ebff700 (LWP 31962)):
#0  0x00007f8381466bdd in poll () from /lib64/libc.so.6
#1  0x00007f837f928bb8 in check_stdin_thread () from /opt/couchbase/lib/memcached/stdin_term_handler.so
#2  0x00007f8383c72df8 in platform_thread_wrap () from /opt/couchbase/bin/../lib/libplatform.so.0.1.0
#3  0x00007f838216adf3 in start_thread () from /lib64/libpthread.so.0
#4  0x00007f83814711ad in clone () from /lib64/libc.so.6

Thread 10 (Thread 0x7f837e1f9700 (LWP 31963)):
#0  0x00007f838216eab2 in pthread_cond_timedwait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
#1  0x00007f8383c72fd5 in cb_cond_timedwait () from /opt/couchbase/bin/../lib/libplatform.so.0.1.0
#2  0x00007f837e1fbbfb in logger_thead_main(void*) () from /opt/couchbase/lib/memcached/file_logger.so
#3  0x00007f8383c72df8 in platform_thread_wrap () from /opt/couchbase/bin/../lib/libplatform.so.0.1.0
#4  0x00007f838216adf3 in start_thread () from /lib64/libpthread.so.0
#5  0x00007f83814711ad in clone () from /lib64/libc.so.6

Thread 9 (Thread 0x7f837d9f8700 (LWP 31964)):
#0  0x00007f838216eab2 in pthread_cond_timedwait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
#1  0x00007f8383c72fd5 in cb_cond_timedwait () from /opt/couchbase/bin/../lib/libplatform.so.0.1.0
#2  0x00007f838429898e in consume_events(void*) () from /opt/couchbase/bin/../lib/libauditd.so.0.1.0
#3  0x00007f8383c72df8 in platform_thread_wrap () from /opt/couchbase/bin/../lib/libplatform.so.0.1.0
#4  0x00007f838216adf3 in start_thread () from /lib64/libpthread.so.0
#5  0x00007f83814711ad in clone () from /lib64/libc.so.6

Thread 8 (Thread 0x7f837cde8700 (LWP 31965)):
#0  0x00007f838216e705 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
#1  0x00007f8381d0556c in std::condition_variable::wait(std::unique_lock<std::mutex>&) () from /lib64/libstdc++.so.6
#2  0x00007f837cdec78d in ScrubberTask::run() () from /opt/couchbase/bin/../lib/../lib/memcached/default_engine.so
#3  0x00007f8383c72df8 in platform_thread_wrap () from /opt/couchbase/bin/../lib/libplatform.so.0.1.0
#4  0x00007f838216adf3 in start_thread () from /lib64/libpthread.so.0
#5  0x00007f83814711ad in clone () from /lib64/libc.so.6

Thread 7 (Thread 0x7f83787ff700 (LWP 31966)):
#0  0x00007f8381471783 in epoll_wait () from /lib64/libc.so.6
#1  0x00007f8383205ef3 in epoll_dispatch (base=0x7f837ec22280, tv=<optimized out>) at /home/couchbase/jenkins/workspace/cbdeps-build/label/centos7/release/sherlock/deps/packages/build/libevent/libevent-prefix/src/libevent/epoll.c:407
#2  0x00007f83831f2fa2 in event_base_loop (base=0x7f837ec22280, flags=0) at /home/couchbase/jenkins/workspace/cbdeps-build/label/centos7/release/sherlock/deps/packages/build/libevent/libevent-prefix/src/libevent/event.c:1625
#3  0x0000000000438174 in worker_libevent(void*) ()
#4  0x00007f8383c72df8 in platform_thread_wrap () from /opt/couchbase/bin/../lib/libplatform.so.0.1.0
#5  0x00007f838216adf3 in start_thread () from /lib64/libpthread.so.0
#6  0x00007f83814711ad in clone () from /lib64/libc.so.6

Thread 6 (Thread 0x7f8377ffe700 (LWP 31967)):
#0  0x00007f8381471783 in epoll_wait () from /lib64/libc.so.6
#1  0x00007f8383205ef3 in epoll_dispatch (base=0x7f837ec22500, tv=<optimized out>) at /home/couchbase/jenkins/workspace/cbdeps-build/label/centos7/release/sherlock/deps/packages/build/libevent/libevent-prefix/src/libevent/epoll.c:407
#2  0x00007f83831f2fa2 in event_base_loop (base=0x7f837ec22500, flags=0) at /home/couchbase/jenkins/workspace/cbdeps-build/label/centos7/release/sherlock/deps/packages/build/libevent/libevent-prefix/src/libevent/event.c:1625
#3  0x0000000000438174 in worker_libevent(void*) ()
#4  0x00007f8383c72df8 in platform_thread_wrap () from /opt/couchbase/bin/../lib/libplatform.so.0.1.0
#5  0x00007f838216adf3 in start_thread () from /lib64/libpthread.so.0
#6  0x00007f83814711ad in clone () from /lib64/libc.so.6

Thread 5 (Thread 0x7f83777fd700 (LWP 31968)):
#0  0x00007f8381471783 in epoll_wait () from /lib64/libc.so.6
#1  0x00007f8383205ef3 in epoll_dispatch (base=0x7f837ec22780, tv=<optimized out>) at /home/couchbase/jenkins/workspace/cbdeps-build/label/centos7/release/sherlock/deps/packages/build/libevent/libevent-prefix/src/libevent/epoll.c:407
#2  0x00007f83831f2fa2 in event_base_loop (base=0x7f837ec22780, flags=0) at /home/couchbase/jenkins/workspace/cbdeps-build/label/centos7/release/sherlock/deps/packages/build/libevent/libevent-prefix/src/libevent/event.c:1625
#3  0x0000000000438174 in worker_libevent(void*) ()
#4  0x00007f8383c72df8 in platform_thread_wrap () from /opt/couchbase/bin/../lib/libplatform.so.0.1.0
#5  0x00007f838216adf3 in start_thread () from /lib64/libpthread.so.0
#6  0x00007f83814711ad in clone () from /lib64/libc.so.6

Thread 4 (Thread 0x7f8376ffc700 (LWP 31969)):
#0  0x00007f8381471783 in epoll_wait () from /lib64/libc.so.6
#1  0x00007f8383205ef3 in epoll_dispatch (base=0x7f837ec22a00, tv=<optimized out>) at /home/couchbase/jenkins/workspace/cbdeps-build/label/centos7/release/sherlock/deps/packages/build/libevent/libevent-prefix/src/libevent/epoll.c:407
#2  0x00007f83831f2fa2 in event_base_loop (base=0x7f837ec22a00, flags=0) at /home/couchbase/jenkins/workspace/cbdeps-build/label/centos7/release/sherlock/deps/packages/build/libevent/libevent-prefix/src/libevent/event.c:1625
#3  0x0000000000438174 in worker_libevent(void*) ()
#4  0x00007f8383c72df8 in platform_thread_wrap () from /opt/couchbase/bin/../lib/libplatform.so.0.1.0
#5  0x00007f838216adf3 in start_thread () from /lib64/libpthread.so.0
#6  0x00007f83814711ad in clone () from /lib64/libc.so.6

Thread 3 (Thread 0x7f83767fb700 (LWP 31970)):
#0  0x00007f8381471783 in epoll_wait () from /lib64/libc.so.6
#1  0x00007f8383205ef3 in epoll_dispatch (base=0x7f837ec22c80, tv=<optimized out>) at /home/couchbase/jenkins/workspace/cbdeps-build/label/centos7/release/sherlock/deps/packages/build/libevent/libevent-prefix/src/libevent/epoll.c:407
#2  0x00007f83831f2fa2 in event_base_loop (base=0x7f837ec22c80, flags=0) at /home/couchbase/jenkins/workspace/cbdeps-build/label/centos7/release/sherlock/deps/packages/build/libevent/libevent-prefix/src/libevent/event.c:1625
#3  0x0000000000438174 in worker_libevent(void*) ()
#4  0x00007f8383c72df8 in platform_thread_wrap () from /opt/couchbase/bin/../lib/libplatform.so.0.1.0
#5  0x00007f838216adf3 in start_thread () from /lib64/libpthread.so.0
#6  0x00007f83814711ad in clone () from /lib64/libc.so.6

Thread 2 (Thread 0x7f83757f9700 (LWP 781)):
#0  0x00007f83814384dd in nanosleep () from /lib64/libc.so.6
#1  0x00007f8381469054 in usleep () from /lib64/libc.so.6
#2  0x00007f837c33c215 in updateStatsThread () from /opt/couchbase/bin/../lib/../lib/memcached/ep.so
#3  0x00007f8383c72df8 in platform_thread_wrap () from /opt/couchbase/bin/../lib/libplatform.so.0.1.0
#4  0x00007f838216adf3 in start_thread () from /lib64/libpthread.so.0
#5  0x00007f83814711ad in clone () from /lib64/libc.so.6

Thread 1 (Thread 0x7f83846a98c0 (LWP 31956)):
#0  0x00007f8381471783 in epoll_wait () from /lib64/libc.so.6
#1  0x00007f8383205ef3 in epoll_dispatch (base=0x7f837ec22000, tv=<optimized out>) at /home/couchbase/jenkins/workspace/cbdeps-build/label/centos7/release/sherlock/deps/packages/build/libevent/libevent-prefix/src/libevent/epoll.c:407
#2  0x00007f83831f2fa2 in event_base_loop (base=0x7f837ec22000, flags=0) at /home/couchbase/jenkins/workspace/cbdeps-build/label/centos7/release/sherlock/deps/packages/build/libevent/libevent-prefix/src/libevent/event.c:1625
#3  0x000000000040dd7d in main ()