Thanks for your support.. this is dmesg|grep -E "kill|mysql|oom"
[159648.572125] mysqld invoked oom-killer: gfp_mask=0x1100cca(GFP_HIGHUSER_MOVABLE), order=0, oom_score_adj=0
[159648.572132] CPU: 0 PID: 206072 Comm: mysqld Not tainted 5.15.0-105-generic #115-Ubuntu
[159648.572157] oom_kill_process.cold+0xb/0x10
[159648.572292] [ pid ] uid tgid total_vm rss pgtables_bytes swapents oom_score_adj name
[159648.572400] [ 187430] 0 187430 1909 613 49152 0 0 mysqld_safe
[159648.572402] [ 188043] 1001 188043 803948 154188 1720320 0 0 mysqld
[159648.572542] oom-kill:constraint=CONSTRAINT_NONE,nodemask=(null),cpuset=mysqld.service,mems_allowed=0,global_oom,task_memcg=/system.slice/mysqld.service,task=mysqld,pid=188043,uid=1001
[159648.572665] Out of memory: Killed process 188043 (mysqld) total-vm:3215792kB, anon-rss:616752kB, file-rss:0kB, shmem-rss:0kB, UID:1001 pgtables:1680kB oom_score_adj:0
[159652.720242] systemd invoked oom-killer: gfp_mask=0x1100cca(GFP_HIGHUSER_MOVABLE), order=0, oom_score_adj=0
[159652.720270] oom_kill_process.cold+0xb/0x10
[159652.720383] [ pid ] uid tgid total_vm rss pgtables_bytes swapents oom_score_adj name
[159652.720488] [ 187430] 0 187430 1909 618 49152 0 0 mysqld_safe
[159652.720609] [ 206630] 1001 206630 798203 71747 966656 0 0 mysqld
[159652.720620] oom-kill:constraint=CONSTRAINT_NONE,nodemask=(null),cpuset=init.scope,mems_allowed=0,global_oom,task_memcg=/system.slice/mysqld.service,task=mysqld,pid=206630,uid=1001
[159652.720678] Out of memory: Killed process 206630 (mysqld) total-vm:3192812kB, anon-rss:286988kB, file-rss:0kB, shmem-rss:0kB, UID:1001 pgtables:944kB oom_score_adj:0
[159653.413378] mysqld invoked oom-killer: gfp_mask=0x1100dca(GFP_HIGHUSER_MOVABLE|__GFP_ZERO), order=0, oom_score_adj=0
[159653.413386] CPU: 1 PID: 206725 Comm: mysqld Not tainted 5.15.0-105-generic #115-Ubuntu
[159653.413407] oom_kill_process.cold+0xb/0x10
[159653.413506] [ pid ] uid tgid total_vm rss pgtables_bytes swapents oom_score_adj name
[159653.413632] [ 187430] 0 187430 1909 585 49152 0 0 mysqld_safe
[159653.413788] [ 206725] 1001 206725 285766 51098 561152 0 0 mysqld
[159653.413789] oom-kill:constraint=CONSTRAINT_NONE,nodemask=(null),cpuset=mysqld.service,mems_allowed=0,global_oom,task_memcg=/system.slice/mysqld.service,task=mysqld,pid=206725,uid=1001
[159653.413811] Out of memory: Killed process 206725 (mysqld) total-vm:1143064kB, anon-rss:202128kB, file-rss:2264kB, shmem-rss:0kB, UID:1001 pgtables:548kB oom_score_adj:0