why Change the status of Mysql to Failed every few hours - mysql

Question

Mysql status fails every few hours, I also checked the buffer size, no problem with them and
The following message is displayed with the below command:
systemctl status mysqld
● mysqld.service - MySQL Server
Loaded: loaded (/usr/lib/systemd/system/mysqld.service; enabled; vendor preset: disabled)
Active: failed (Result: start-limit) since Wed 2020-12-02 17:05:42 EST; 8h ago
Docs: man:mysqld(8)
http://dev.mysql.com/doc/refman/en/using-systemd.html
Process: 25565 ExecStart=/usr/sbin/mysqld --daemonize --pid-file=/var/run/mysqld/mysqld.pid $MYSQLD_OPTS (code=exited, status=1/FAILURE)
Process: 25543 ExecStartPre=/usr/bin/mysqld_pre_systemd (code=exited, status=0/SUCCESS)
Main PID: 17582 (code=killed, signal=KILL)
Dec 02 17:05:42 test.local systemd[1]: Failed to start MySQL Server.
Dec 02 17:05:42 test.local systemd[1]: Unit mysqld.service entered failed state.
Dec 02 17:05:42 test.local systemd[1]: mysqld.service failed.
Dec 02 17:05:42 test.local systemd[1]: mysqld.service holdoff time over, scheduling restart.
Dec 02 17:05:42 test.local systemd[1]: Stopped MySQL Server.
Dec 02 17:05:42 test.local systemd[1]: start request repeated too quickly for mysqld.service
Dec 02 17:05:42 test.local systemd[1]: Failed to start MySQL Server.
Dec 02 17:05:42 test.local systemd[1]: Unit mysqld.service entered failed state.
Dec 02 17:05:42 test.local systemd[1]: mysqld.service failed.
I also checked the log file and the following event occurred:
2020-12-02T22:05:42.179677Z 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation $2020-12-02T22:05:42.184072Z 0 [Note] /usr/sbin/mysqld (mysqld 5.7.31) starting as process 25570 ...
2020-12-02T22:05:42.204497Z 0 [Note] InnoDB: PUNCH HOLE support available
2020-12-02T22:05:42.204557Z 0 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
2020-12-02T22:05:42.204565Z 0 [Note] InnoDB: Uses event mutexes
2020-12-02T22:05:42.204574Z 0 [Note] InnoDB: GCC builtin __atomic_thread_fence() is used for memory barrier
2020-12-02T22:05:42.204579Z 0 [Note] InnoDB: Compressed tables use zlib 1.2.11
2020-12-02T22:05:42.204584Z 0 [Note] InnoDB: Using Linux native AIO
2020-12-02T22:05:42.204998Z 0 [Note] InnoDB: Number of pools: 1
2020-12-02T22:05:42.205184Z 0 [Note] InnoDB: Using CPU crc32 instructions
2020-12-02T22:05:42.208098Z 0 [Note] InnoDB: Initializing buffer pool, total size = 6G, instances = 8, chunk size = 128M
2020-12-02T22:05:42.443914Z 0 [ERROR] InnoDB: mmap(137428992 bytes) failed; errno 12
2020-12-02T22:05:42.510301Z 0 [ERROR] InnoDB: Cannot allocate memory for the buffer pool
2020-12-02T22:05:42.510359Z 0 [ERROR] InnoDB: Plugin initialization aborted with error Generic error
2020-12-02T22:05:42.510376Z 0 [ERROR] Plugin 'InnoDB' init function returned error.
2020-12-02T22:05:42.510384Z 0 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed.
2020-12-02T22:05:42.510391Z 0 [ERROR] Failed to initialize builtin plugins.
2020-12-02T22:05:42.510399Z 0 [ERROR] Aborting
2020-12-02T22:05:42.510438Z 0 [Note] Binlog end
2020-12-02T22:05:42.510525Z 0 [Note] Shutting down plugin 'CSV'
2020-12-02T22:05:42.511922Z 0 [Note] /usr/sbin/mysqld: Shutdown complete
also My.cf file:
[mysqld]
datadir = /var/lib/mysql
socket = /var/lib/mysql/mysql.sock
symbolic-links=0
innodb_file_per_table = 1
myisam_sort_buffer_size = 64M
read_rnd_buffer_size = 1024K
net_buffer_length = 8K
read_buffer_size = 1024K
sort_buffer_size = 1024K
table_open_cache = 64
max_allowed_packet = 2M
key_buffer_size = 64M
innodb_buffer_pool_size = 6024M
log-error=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid
I tested this project on a server with 2 GB of RAM, but it failed on a server with 8 GB of RAM.

Answer 1

Consider these changes to your my.cnf [mysqld] section
innodb_buffer_pool_size=4G
and REMOVE to allow defaults to work for improved performance
read_rnd_buffer_size
read_buffer_size
sort_buffer_size
to reduce RAM footprint.
For additional suggestions, view my profile, Network profile for contact info and free downloadable Utility Scripts to assist with performance tuning.