/usr/lib64/maxscale/libmaxscale-common.so.1.0.0(_Z12gwbuf_appendP5GWBUFS0_+0x9): server/core/buffer.cc:523

  /usr/lib64/maxscale/libmaxscale-common.so.1.0.0(_ZN3DCB13writeq_appendEP5GWBUFNS_5DrainE+0x6c): server/core/dcb.cc:639

  /usr/lib64/maxscale/libmaxscale-common.so.1.0.0(_ZN24MariaDBBackendConnection17finish_connectionEv+0x5d): server/modules/protocol/MariaDB/mariadb_backend.cc:179

  /usr/lib64/maxscale/libmaxscale-common.so.1.0.0(_ZN3DCB7destroyEv+0x55): server/core/dcb.cc:788

  /usr/lib64/maxscale/libmaxscale-common.so.1.0.0(_ZN8maxscale13RoutingWorker14delete_zombiesEv+0x61): /usr/include/c++/8/bits/stl_vector.h:895

  /usr/lib64/maxscale/libmaxscale-common.so.1.0.0(_ZN8maxscale13RoutingWorker10epoll_tickEv+0x1d): /usr/include/c++/8/bits/stl_iterator.h:784

  /usr/lib64/maxscale/libmaxscale-common.so.1.0.0(_ZN7maxbase6Worker15poll_waiteventsEv+0x359): maxutils/maxbase/src/worker.cc:784

  /usr/lib64/maxscale/libmaxscale-common.so.1.0.0(_ZN7maxbase6Worker3runEPNS_9SemaphoreE+0x4f): maxutils/maxbase/src/worker.cc:562

  /lib64/libstdc++.so.6(+0xc2ba3): ??:?

  /lib64/libpthread.so.0(+0x814a): pthread_create.c:?

  /lib64/libc.so.6(clone+0x43): :?