Hello guys
I was having similar problems. Mariadb closed unexpectedly with the error "signal 11". It returned quickly and the node joined the cluster. But it was happening frequently.
Monitoring my loadbalancers I noticed that the moodle cron script that should be run every one minute caused the lock.
As I only have 2 instances of application, I put one to run in odd minutes and the other in even minutes.
They are not yet in production, and I don't know if I would have problems again when I have a lot of users using it.
1 [ERROR] mysqld got signal 11 ;
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 https://mariadb.com/kb/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: 10.3.25-MariaDB-0+deb10u1
key_buffer_size=134217728
read_buffer_size=131072
max_used_connections=2
max_threads=153
thread_count=10
It is possible that mysqld could use up to
key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 467424 K bytes of memory
Hope that's ok; if not, decrease some variables in the equation.
Thread pointer: 0x7f4bec000f38
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 = 0x7f4c44080dd8 thread_stack 0x49000
/usr/sbin/mysqld(my_print_stacktrace+0x2e)[0x55c199b2a05e]
/usr/sbin/mysqld(handle_fatal_signal+0x54d)[0x55c19965d09d]
/lib/x86_64-linux-gnu/libpthread.so.0(+0x12730)[0x7f4c48890730]
/usr/sbin/mysqld(_Z11ull_get_keyPKhPmc+0x14)[0x55c1996b3f54]
/usr/sbin/mysqld(+0xc5322d)[0x55c199b1122d]
/usr/sbin/mysqld(my_hash_first_from_hash_value+0x87)[0x55c199b11487]
/usr/sbin/mysqld(my_hash_search+0x11)[0x55c199b11571]
/usr/sbin/mysqld(_ZN18Item_func_get_lock7val_intEv+0x15c)[0x55c1996b69cc]
/usr/sbin/mysqld(_ZNK12Type_handler14Item_send_longEP4ItemP8ProtocolP8st_value+0x19)[0x55c1995ba829]
/usr/sbin/mysqld(_ZN8Protocol19send_result_set_rowEP4ListI4ItemE+0xb5)[0x55c1993e8e35]
/usr/sbin/mysqld(_ZN11select_send9send_dataER4ListI4ItemE+0x5b)[0x55c199448b2b]
/usr/sbin/mysqld(_ZN4JOIN10exec_innerEv+0xae6)[0x55c1994df1f6]
/usr/sbin/mysqld(_ZN4JOIN4execEv+0x33)[0x55c1994df3d3]
/usr/sbin/mysqld(_Z12mysql_selectP3THDP10TABLE_LISTjR4ListI4ItemEPS4_jP8st_orderS9_S7_S9_yP13select_resultP18st_select_lex_unitP13st_select_lex+0xef)[0x55c1994ddaaf]
/usr/sbin/mysqld(_Z13handle_selectP3THDP3LEXP13select_resultm+0x14d)[0x55c1994de38d]
/usr/sbin/mysqld(+0x5c1d8c)[0x55c19947fd8c]
/usr/sbin/mysqld(_Z21mysql_execute_commandP3THD+0x5857)[0x55c19948c087]
/usr/sbin/mysqld(_Z11mysql_parseP3THDPcjP12Parser_statebb+0x1c9)[0x55c19948e879]
/usr/sbin/mysqld(+0x5d1189)[0x55c19948f189]
/usr/sbin/mysqld(_Z16dispatch_command19enum_server_commandP3THDPcjbb+0x1423)[0x55c199490a33]
/usr/sbin/mysqld(_Z10do_commandP3THD+0x122)[0x55c199491e82]
/usr/sbin/mysqld(_Z24do_handle_one_connectionP7CONNECT+0x23a)[0x55c1995631ba]
/usr/sbin/mysqld(handle_one_connection+0x3d)[0x55c19956333d]
/lib/x86_64-linux-gnu/libpthread.so.0(+0x7fa3)[0x7f4c48885fa3]
/lib/x86_64-linux-gnu/libc.so.6(clone+0x3f)[0x7f4c47f0f4cf]
Trying to get some variables.
Some pointers may be invalid and cause the dump to abort.
Query (0x7f4bec010aa0): SELECT GET_LOCK('9bd9299a857ef274cb0d0ecf33b68d21f775bcb1', '0') AS locked
Connection ID (thread ID): 2207
Status: NOT_KILLED
Optimizer switch: index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,engine_condition_pushdown=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=on,loosescan=on,materialization=on,in_to_exists=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=off,mrr_cost_based=off,mrr_sort_keys=off,outer_join_with_cache=on,semijoin_with_cache=on,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=off,table_elimination=on,extended_keys=on,exists_to_in=on,orderby_uses_equalities=on,condition_pushdown_for_derived=on,split_materialized=on
The manual page at https://mariadb.com/kb/en/how-to-produce-a-full-stack-trace-for-mysqld/ contains
information that should help you find out what is causing the crash.
Writing a core file...
Working directory at /var/lib/mysql
Resource Limits:
Limit Soft Limit Hard Limit Units
Max cpu time unlimited unlimited seconds
Max file size unlimited unlimited bytes
Max data size unlimited unlimited bytes
Max stack size 8388608 unlimited bytes
Max core file size 0 unlimited bytes
Max resident set unlimited unlimited bytes
Max processes 7864 7864 processes
Max open files 16384 16384 files
Max locked memory 65536 65536 bytes
Max address space unlimited unlimited bytes
Max file locks unlimited unlimited locks
Max pending signals 7864 7864 signals
Max msgqueue size 819200 819200 bytes
Max nice priority 0 0
Max realtime priority 0 0
Max realtime timeout unlimited unlimited us
Core pattern: core
