Comment 2 for bug 1321767

Today happen again:

F-BF X lock conflict
RECORD LOCKS space id 1173403 page no 4 n bits 256 index `GEN_CLUST_INDEX` of table `assistenza`.`temp_mdem520` trx id 4B4C7D5 lock_mode X locks rec but not gap
08:16:24 UTC - mysqld got signal 6 ;
This could be because you hit a bug. It is also possible that this binary
or one of the libraries it was linked against is corrupt, improperly built,
or misconfigured. This error can also be caused by malfunctioning hardware.
We will try our best to scrape up some info that will hopefully help
diagnose the problem, but since we have already crashed,
something is definitely wrong and this may fail.
Please help us make Percona XtraDB Cluster better by reporting any
bugs at https://bugs.launchpad.net/percona-xtradb-cluster

key_buffer_size=33554432
read_buffer_size=2097152
max_used_connections=36
max_threads=252
thread_count=33
connection_count=33
It is possible that mysqld could use up to
key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 1068175 K bytes of memory
Hope that's ok; if not, decrease some variables in the equation.

Thread pointer: 0x7f67b232d9c0
Attempting backtrace. You can use the following information to find out
where mysqld died. If you see no messages after this, something went
terribly wrong...

onnection_count=33
It is possible that mysqld could use up to
key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 1068175 K bytes of memory
Hope that's ok; if not, decrease some variables in the equation.

Thread pointer: 0x7f67b232d9c0
Attempting backtrace. You can use the following information to find out
where mysqld died. If you see no messages after this, something went
terribly wrong...
stack_bottom = 7f6511e56a88 thread_stack 0x40000
/usr/sbin/mysqld(my_print_stacktrace+0x2e)[0x7f67ac3db8be]
/usr/sbin/mysqld(handle_fatal_signal+0x4a3)[0x7f67ac2b0fe3]
/lib/libpthread.so.0(+0xeff0)[0x7f67aba56ff0]
/lib/libc.so.6(gsignal+0x35)[0x7f67a9d101b5]
/lib/libc.so.6(abort+0x180)[0x7f67a9d12fc0]
/usr/sbin/mysqld(+0x68df12)[0x7f67ac511f12]
/usr/sbin/mysqld(+0x69099b)[0x7f67ac51499b]
/usr/sbin/mysqld(+0x6921e9)[0x7f67ac5161e9]
/usr/sbin/mysqld(+0x692491)[0x7f67ac516491]
/usr/sbin/mysqld(+0x5d24b7)[0x7f67ac4564b7]
/usr/sbin/mysqld(+0x5d5864)[0x7f67ac459864]
/usr/sbin/mysqld(+0x5aafe7)[0x7f67ac42efe7]
/usr/sbin/mysqld(+0x5a2e77)[0x7f67ac426e77]
/usr/sbin/mysqld(+0x5aa077)[0x7f67ac42e077]
/usr/sbin/mysqld(_ZN14Rows_log_event8find_rowEPK14Relay_log_info+0x1d9)[0x7f67ac357389]
/usr/sbin/mysqld(_ZN21Update_rows_log_event11do_exec_rowEPK14Relay_log_info+0xa6)[0x7f67ac3578a6]
/usr/sbin/mysqld(_ZN14Rows_log_event14do_apply_eventEPK14Relay_log_info+0x24b)[0x7f67ac35e7db]
/usr/sbin/mysqld(_Z14wsrep_apply_cbPvPKvmjPK14wsrep_trx_meta+0x5dd)[0x7f67ac26dbed]
/usr/lib64/libgalera_smm.so(+0x1a2909)[0x7f67a8e48909]
/usr/lib64/libgalera_smm.so(_ZN6galera13ReplicatorSMM9apply_trxEPvPNS_9TrxHandleE+0x273)[0x7f67a8e4afc3]
/usr/lib64/libgalera_smm.so(_ZN6galera13ReplicatorSMM11process_trxEPvPNS_9TrxHandleE+0x45)[0x7f67a8e4b915]
/usr/lib64/libgalera_smm.so(_ZN6galera15GcsActionSource8dispatchEPvRK10gcs_actionRb+0x3d4)[0x7f67a8e27464]
/usr/lib64/libgalera_smm.so(_ZN6galera15GcsActionSource7processEPvRb+0x63)[0x7f67a8e27a63]
/usr/lib64/libgalera_smm.so(_ZN6galera13ReplicatorSMM10async_recvEPv+0x93)[0x7f67a8e46eb3]
/usr/lib64/libgalera_smm.so(galera_recv+0x23)[0x7f67a8e5f9f3]
/usr/sbin/mysqld(+0x3ea9ef)[0x7f67ac26e9ef]
/usr/sbin/mysqld(start_wsrep_THD+0x431)[0x7f67ac122531]
/lib/libpthread.so.0(+0x68ca)[0x7f67aba4e8ca]
/lib/libc.so.6(clone+0x6d)[0x7f67a9dadb6d]

Trying to get some variables.
Some pointers may be invalid and cause the dump to abort.
Query (0): Connection ID (thread ID): 22
Status: NOT_KILLED

You may download the Percona XtraDB Cluster operations manual by visiting
http://www.percona.com/software/percona-xtradb-cluster/. You may find information
in the manual which will help you identify the cause of the crash.
140529 10:16:25 mysqld_safe Number of processes running now: 0
140529 10:16:25 mysqld_safe WSREP: not restarting wsrep node automatically
140529 10: