segmentation fault in wsrep_unload()

[Teemu Ollakka]

Regression test for lp:1208493 causes mysqld to crash in:

2014-05-14 04:28:59 31625 [Note] WSREP: wsrep_provider_update: /tmp/galera/local1/galera/lib/libgalera_smm.so
2014-05-14 04:28:59 31625 [Note] WSREP: Stop replication
2014-05-14 04:28:59 31625 [Note] WSREP: Provider disconnect
2014-05-14 04:28:59 31625 [Note] [Debug] WSREP: dummy_disconnect
2014-05-14 04:29:01 31625 [Note] WSREP: waiting for client connections to close: 1
2014-05-14 04:29:01 31625 [Note] [Debug] WSREP: dummy_free
04:29:01 UTC - mysqld got signal 11 ;

Stack trace:

#0 0x00007f545ddabf8c in pthread_kill ()
   from /lib/x86_64-linux-gnu/libpthread.so.0
#1 0x0000000000adb704 in my_write_core (sig=11)
    at /home/vagrant/codership-mysql/mysys/stacktrace.c:422
#2 0x000000000075088e in handle_fatal_signal (sig=11)
    at /home/vagrant/codership-mysql/sql/signal_handler.cc:248
#3 <signal handler called>
#4 0x00007f545d24c771 in ?? () from /lib/x86_64-linux-gnu/libc.so.6
#5 0x0000000000eb2e1f in wsrep_unload (hptr=0x7f541195c340)
    at /home/vagrant/codership-mysql/wsrep/wsrep_loader.c:200
#6 0x0000000000644c6b in wsrep_deinit ()
    at /home/vagrant/codership-mysql/sql/wsrep_mysqld.cc:705
#7 0x000000000065034a in wsrep_provider_update (self=0x17d1ec0,
    thd=0x3a0ab20, type=OPT_GLOBAL)
    at /home/vagrant/codership-mysql/sql/wsrep_var.cc:241
#8 0x000000000074e2f8 in sys_var::update (this=0x17d1ec0, thd=0x3a0ab20,
    var=0x7f5410005290) at /home/vagrant/codership-mysql/sql/set_var.cc:194
#9 0x000000000074f462 in set_var::update (this=0x7f5410005290, thd=0x3a0ab20)
    at /home/vagrant/codership-mysql/sql/set_var.cc:670
#10 0x000000000074f036 in sql_set_variables (thd=0x3a0ab20, var_list=0x3a0db00)
    at /home/vagrant/codership-mysql/sql/set_var.cc:573
#11 0x0000000000805d15 in mysql_execute_command (thd=0x3a0ab20)
    at /home/vagrant/codership-mysql/sql/sql_parse.cc:4036
#12 0x000000000080e0d6 in mysql_parse (thd=0x3a0ab20,
    rawbuf=0x7f5410005070 "set global wsrep_provider='/tmp/galera/local1/galera/lib/libgalera_smm.so'", length=74, parser_state=0x7f544c472170)
    at /home/vagrant/codership-mysql/sql/sql_parse.cc:6775
#13 0x000000000080d6e7 in wsrep_mysql_parse (thd=0x3a0ab20,
    rawbuf=0x7f5410005070 "set global wsrep_provider='/tmp/galera/local1/galera/lib/libgalera_smm.so'", length=74, parser_state=0x7f544c472170)
    at /home/vagrant/codership-mysql/sql/sql_parse.cc:6555
#14 0x00000000007ff5a1 in dispatch_command (command=COM_QUERY, thd=0x3a0ab20,
    packet=0x3617951 "set global wsrep_provider='/tmp/galera/local1/galera/lib/libgalera_smm.so'", packet_length=74)
    at /home/vagrant/codership-mysql/sql/sql_parse.cc:1526
#15 0x00000000007fe0e3 in do_command (thd=0x3a0ab20)
    at /home/vagrant/codership-mysql/sql/sql_parse.cc:1118
#16 0x00000000007c4a81 in do_handle_one_connection (thd_arg=0x3a0ab20)
    at /home/vagrant/codership-mysql/sql/sql_connect.cc:1007
#17 0x00000000007c4501 in handle_one_connection (arg=0x3a0ab20)
    at /home/vagrant/codership-mysql/sql/sql_connect.cc:916
#18 0x00007f545dda6e9a in start_thread ()
   from /lib/x86_64-linux-gnu/libpthread.so.0
#19 0x00007f545d2c13fd in clone () from /lib/x86_64-linux-gnu/libc.so.6
#20 0x0000000000000000 in ?? ()

[Raghavendra D Prabhu (raghavendra-prabhu)]

Is this crash still reproduceable

[Alex Yurchenko (ayurchen)]

It may be related to: https://github.com/codership/galera/issues/189

[Krunal Bauskar (krunal-bauskar)]

setting

set global wsrep_provider=none;

would trigger this scenario but I don't see this failure with latest PXC-5.6

[Shahriyar Rzayev (rzayev-sehriyar)]

Percona now uses JIRA for bug reports so this bug report is migrated to: https://jira.percona.com/browse/PXC-1003