mysqld无法启动（php-fpm开启过多导致）

╰+攻爆jí腚メ 2023-03-14 13:15 1阅读 0赞

mysql数据库挂了，无法重启

$ service mysqld status
    MySQL is not running, but lock file (/var/lock/subsys/mysql[FAILED]
    
    $ service mysqld stop
    MySQL server PID file could not be found! 
    
    $ service mysqld start
    Starting MySQL.The server quit without updating PID file (/[FAILED]er/data/iZwz9a0ptppx6qcloucmdrZ.pid).
    [root@iZwz9a0ptppx6qcloucmdrZ subsys]# find / -name 'iZwz9a0ptppx6qcloucmdrZ.pid'
    
    $ service mysqld restart
    MySQL server PID file could not be found!                  [FAILED]
    Starting MySQL.The server quit without updating PID file (/[FAILED]er/data/iZwz9a0ptppx6qcloucmdrZ.pid).

查看一下mysql报错日子

InnoDB: mmap(137363456 bytes) failed; errno 12
    2020-05-17 22:47:14 25396 [ERROR] InnoDB: Cannot allocate memory for the buffer pool
    2020-05-17 22:47:14 25396 [ERROR] Plugin 'InnoDB' init function returned error.
    2020-05-17 22:47:14 25396 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed.
    2020-05-17 22:47:14 25396 [ERROR] Unknown/unsupported storage engine: InnoDB
    2020-05-17 22:47:14 25396 [ERROR] Aborting

内存不足了，启动不了mysql，于是看一下原因，是什么导致内存不足

查看内存使用情况

free -m
                 total       used       free     shared    buffers     cached
    Mem:          3961       3627        333          0         60         33
    -/+ buffers/cache:       3533        427
    Swap:            0          0          0

剩下333M可用，肯定启动不了`mysql`

查看启动的php-fpm数量

ps -fe |grep "php-fpm"|grep "pool"|wc -l
    143

> 平均一个php-fpm的内存消耗 `0.5~1%`，通常一个php-fpm为3M，但是随着内存的泄露后面会达到20~30M，所以一般开100个，可能就会消耗3G内存。

143-137

查看当前连接中的的php-fpm

netstat -anp|grep "php-fpm"|grep "tcp"|grep "pool"|wc -l
    0

修改`php-fpm.conf`的配置

[global]
    pid = /www/server/php/56/var/run/php-fpm.pid
    error_log = /www/server/php/56/var/log/php-fpm.log
    log_level = notice
    
    [www]
    listen = /tmp/php-cgi-56.sock
    listen.backlog = -1
    listen.allowed_clients = 127.0.0.1
    listen.owner = www
    listen.group = www
    listen.mode = 0666
    user = www
    group = www
    pm = dynamic
    pm.status_path = /phpfpm_56_status
    pm.max_children = 1000
    pm.start_servers = 40
    pm.min_spare_servers = 40
    pm.max_spare_servers = 300
    request_terminate_timeout = 2000
    request_slowlog_timeout = 30
    slowlog = var/log/slow.log

pm.max_children = 50
    pm.start_servers = 10
    pm.min_spare_servers = 10
    pm.max_spare_servers = 25
    request_terminate_timeout = 300
    request_slowlog_timeout = 30
    slowlog = var/log/slow.log

重启php-fpm

service php-fpm restart
    service mysqld start
    Starting MySQL..                                           [  OK  ]

内存释放了，重新启动php-fpm  
再启动mysql，解决正常启动