Description:
Sending a SIGTERM signal to MySQL that has connections from the x plugin, the MySQL will be terminated rather than a normal shutdown.
In the strace log,
sudo strace -ff -e ppoll -p 197945
[pid 198030] ppoll([{fd=36, events=POLLIN|POLLPRI}], 1, {tv_sec=0, tv_nsec=500000000}, [], 8) = 1 ([{fd=36, revents=POLLIN}], left {tv_sec=0, tv_nsec=35652
7081})
When the mysqlsh connects to MySQL, the _ss in the ppoll syscall is empty.
When MySQL receives a single, It cannot handle the single.
How to repeat:
- 1. start a mysql
$ /usr/sbin/mysqld --defaults-file=/etc/my.cnf
- 2. start a mysqlsh session
$ mysqlsh "mysqlx://root@127.0.0.1:33060" -uroot -p123
MySQL Shell 8.0.34
Server version: 8.0.34-0ubuntu0.23.04.1 (Ubuntu)
MySQL ubuntu > 127.0.0.1:33060+ JS
- 3. kill mysql process
$ pgrep mysqld
195438
$ kill -15 195438
# The MySQL will be terminated.
Suggested fix:
When accept a connect from x plugin, the MySQL should set the vio->signal_mask.
diff --git a/plugin/x/src/ngs/socket_events.cc b/plugin/x/src/ngs/socket_events.cc
index 582e5b451c2..fb15f8f0fe2 100644
--- a/plugin/x/src/ngs/socket_events.cc
+++ b/plugin/x/src/ngs/socket_events.cc
@@ -34,6 +34,7 @@
#include "plugin/x/src/ngs/memory.h"
#include "plugin/x/src/ngs/socket_events.h"
#include "plugin/x/src/operations_factory.h"
+#include "sql/mysqld.h"
// Surpressing numerous warnings generated by libevent on Windows.
#ifdef WIN32
@@ -93,6 +94,15 @@ class Connection_acceptor_socket : public xpl::iface::Connection_acceptor {
is_tcpip ? VIO_TYPE_TCPIP : VIO_TYPE_SOCKET, 0);
if (!vio) throw std::bad_alloc();
+#ifdef USE_PPOLL_IN_VIO
+ if (vio != nullptr) {
+ // Unset thread_id, to ensure that all shutdowns explicitly set the
+ // current real_id from the THD.
+ vio->thread_id.reset();
+ vio->signal_mask = mysqld_signal_mask;
+ }
+#endif
+
// enable TCP_NODELAY
vio_fastsend(vio);
vio_keepalive(vio, true);
Description: Sending a SIGTERM signal to MySQL that has connections from the x plugin, the MySQL will be terminated rather than a normal shutdown. In the strace log, sudo strace -ff -e ppoll -p 197945 [pid 198030] ppoll([{fd=36, events=POLLIN|POLLPRI}], 1, {tv_sec=0, tv_nsec=500000000}, [], 8) = 1 ([{fd=36, revents=POLLIN}], left {tv_sec=0, tv_nsec=35652 7081}) When the mysqlsh connects to MySQL, the _ss in the ppoll syscall is empty. When MySQL receives a single, It cannot handle the single. How to repeat: - 1. start a mysql $ /usr/sbin/mysqld --defaults-file=/etc/my.cnf - 2. start a mysqlsh session $ mysqlsh "mysqlx://root@127.0.0.1:33060" -uroot -p123 MySQL Shell 8.0.34 Server version: 8.0.34-0ubuntu0.23.04.1 (Ubuntu) MySQL ubuntu > 127.0.0.1:33060+ JS - 3. kill mysql process $ pgrep mysqld 195438 $ kill -15 195438 # The MySQL will be terminated. Suggested fix: When accept a connect from x plugin, the MySQL should set the vio->signal_mask. diff --git a/plugin/x/src/ngs/socket_events.cc b/plugin/x/src/ngs/socket_events.cc index 582e5b451c2..fb15f8f0fe2 100644 --- a/plugin/x/src/ngs/socket_events.cc +++ b/plugin/x/src/ngs/socket_events.cc @@ -34,6 +34,7 @@ #include "plugin/x/src/ngs/memory.h" #include "plugin/x/src/ngs/socket_events.h" #include "plugin/x/src/operations_factory.h" +#include "sql/mysqld.h" // Surpressing numerous warnings generated by libevent on Windows. #ifdef WIN32 @@ -93,6 +94,15 @@ class Connection_acceptor_socket : public xpl::iface::Connection_acceptor { is_tcpip ? VIO_TYPE_TCPIP : VIO_TYPE_SOCKET, 0); if (!vio) throw std::bad_alloc(); +#ifdef USE_PPOLL_IN_VIO + if (vio != nullptr) { + // Unset thread_id, to ensure that all shutdowns explicitly set the + // current real_id from the THD. + vio->thread_id.reset(); + vio->signal_mask = mysqld_signal_mask; + } +#endif + // enable TCP_NODELAY vio_fastsend(vio); vio_keepalive(vio, true);