[#MDEV-11734] mysqld got signal 7

170104 14:43:01 [Note] WSREP: Created page /db/mysql_data/gcache.page.000065 of size 247762356 bytes

170104 14:43:02 [ERROR] mysqld got signal 7 ;

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.

To report this bug, see http://kb.askmonty.org/en/reporting-bugs

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.

Server version: 10.0.23-MariaDB-wsrep-log

key_buffer_size=8388608

read_buffer_size=249856

max_used_connections=25

max_threads=153

thread_count=4

It is possible that mysqld could use up to

key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 58382 K  bytes of memory

Hope that's ok; if not, decrease some variables in the equation.

Thread pointer: 0x0x0

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 = 0x0 thread_stack 0x20000

mysys/stacktrace.c:247(my_print_stacktrace)[0xbfb27e]

sql/signal_handler.cc:153(handle_fatal_signal)[0x73faec]

/lib64/libpthread.so.0[0x355dc0f710]

/lib64/libc.so.6(memcpy+0x310)[0x355d889980]

/usr/local/mysql/lib/libgalera_smm.so(_Z22gcs_defrag_handle_fragP10gcs_defragPK12gcs_act_fragP7gcs_actb+0x126)[0x7f203a48c496]

/usr/local/mysql/lib/libgalera_smm.so(_Z13gcs_core_recvP8gcs_coreP12gcs_act_rcvdx+0x51c)[0x7f203a4936bc]

/usr/local/mysql/lib/libgalera_smm.so(+0x1eda80)[0x7f203a499a80]

/lib64/libpthread.so.0[0x355dc079d1]

/lib64/libc.so.6(clone+0x6d)[0x355d8e89dd]

The manual page at http://dev.mysql.com/doc/mysql/en/crashing.html contains

information that should help you find out what is causing the crash.

170104 14:43:04 mysqld_safe Number of processes running now: 0

170104 14:43:04 mysqld_safe WSREP: not restarting wsrep node automatically

170104 14:43:04 mysqld_safe mysqld from pid file /db/mysql_procfiles/mysql.pid ended

Ok, so the potential fix for this bug would be to check for available disk space and return error if it is not enough for the page file. This may work relatively reliably if access to the partition is limited to gcache. However the problem is the error return.

What may be (naively) expected in this case is that the transaction whose writeset could not be allocated is rolled back and things continue as usual. Unfortunately it is not so. The problem is that the writeset is cached AFTER having been replicated and as a result the node does not know its fate on other nodes. So it must assume the worst and terminate.

So this solution ends up being only marginally better than bus error signal, since the node leaves the cluster gracefully. However bus error is postponed until that part of the page is actually accessed and as such may never happen, giving the node a chance to survive

[MDEV-11734] mysqld got signal 7 Created: 2017-01-06 Updated: 2020-08-25 Resolved: 2018-10-12
Status:	Closed
Project:	MariaDB Server
Component/s:	Galera
Affects Version/s:	10.0.23, 10.0.23-galera
Fix Version/s:	10.0.24-galera

[MDEV-11734] mysqld got signal 7 Created: 2017-01-06 Updated: 2020-08-25 Resolved: 2018-10-12