systemctl status mysqld.service 顯示正在啟動

我已經在測試伺服器（RHEL 7.4）上的單獨掛載點（而不是預設位置）上使用 Linux 通用二進製文件配置了 MySQL 5.7.25 實例。

在這種情況下，必須手動配置 systemd 支持，我就是這樣做的。

我的問題是關於systemctl命令的。當我發出systemctl status mysqld.service時，輸出顯示“啟動（啟動）”但服務“啟動成功”（至少我認為根據警報日誌）並且我沒有得到提示。我必須按 Ctrl+C 才能獲得提示。在其他服務的情況下，systemctl 狀態顯示為活動（已啟動）。此外，systemctl status mysqld.service 顯示“PID 文件 /usr/local/mysql/data/mysqld.pid 在啟動後不可讀（還？）。”

PID 在定義的位置生成，如下面的ls -l輸出所示。

我該如何處理？

以下是 的輸出systemctl status mysqld.service：

> [root@localhost system]# systemctl status mysqld.service ●
> mysqld.service - MySQL Server    Loaded: loaded
> (/usr/lib/systemd/system/mysqld.service; enabled; vendor preset:
> disabled)    Active: **activating (start)** since Wed 2019-03-27
> 16:58:13 IST; 5min ago
>      Docs: man:mysqld(7)
>            http://dev.mysql.com/doc/refman/en/using-systemd.html   Process: 9307
> ExecStart=/mysql/mysql_install/mysql-5.7.25-linux-glibc2.12-x86_64/bin/mysqld
> --lc-messages-dir=/mysql/mysql_install/mysql-5.7.25-linux-glibc2.12-x86_64/share
> --daemonize --pid-file=/mysql/mysql_data/mysqld.pid $MYSQLD_OPTS (code=exited, status=0/SUCCESS)    CGroup:
> /system.slice/mysqld.service
>            └─9309 /mysql/mysql_install/mysql-5.7.25-linux-glibc2.12-x86_64/bin/mysqld
> --lc-messages-dir=/mysql/mysql_install/mysql-5.7.25-linux-glibc2.12-x86_64/share
> --daemonize --pid-file=/mysql/mysql_data/...
> 
> Mar 27 16:58:13 localhost.localdomain systemd[1]: **Starting MySQL
> Server...** Mar 27 16:58:13 localhost.localdomain systemd[1]: **PID
> file /usr/local/mysql/data/mysqld.pid not readable (yet?) after
> start.** [root@localhost system]#

以下是ls -l數據目錄的輸出。

[root@localhost mysql_data]# ls -l
total 122964
-rw-r-----. 1 mysql mysql       56 Mar 27 16:14 auto.cnf
-rw-r-----. 1 mysql mysql      283 Mar 27 16:58 ib_buffer_pool
-rw-r-----. 1 mysql mysql 12582912 Mar 27 16:58 ibdata1
-rw-r-----. 1 mysql mysql 50331648 Mar 27 16:58 ib_logfile0
-rw-r-----. 1 mysql mysql 50331648 Mar 27 16:13 ib_logfile1
-rw-r-----. 1 mysql mysql 12582912 Mar 27 16:58 ibtmp1
drwxr-x---. 2 mysql mysql     4096 Mar 27 16:14 mysql
-rw-r-----. 1 mysql mysql    41256 Mar 27 16:58 mysqld.log
-rw-r-----. 1 mysql mysql        5 Mar 27 16:58 mysqld.pid
srwxrwxrwx. 1 mysql mysql        0 Mar 27 16:58 mysql.sock
-rw-------. 1 mysql mysql        5 Mar 27 16:58 mysql.sock.lock
drwxr-x---. 2 mysql mysql     4096 Mar 27 16:14 performance_schema
drwxr-x---. 2 mysql mysql    12288 Mar 27 16:14 sys
[root@localhost mysql_data]# 

以下是/usr/lib/systemd/system/mysqld.service文件：

[root@localhost system]# cat mysqld.service
[Unit]
Description=MySQL
Server Documentation=man:mysqld(7)
Documentation=http://dev.mysql.com/doc/refman/en/using-systemd.html
After=network.target
After=syslog.target

[Install]
WantedBy=multi-user.target

[Service] 
User=mysql
Group=mysql

Type=forking

PIDFile=/usr/local/mysql/data/mysqld.pid

# Disable service start and stop timeout logic of systemd for mysqld service. 
TimeoutSec=0

# Start main service
ExecStart=/mysql/mysql_install/mysql-5.7.25-linux-glibc2.12-x86_64/bin/mysqld --lc-messages-dir=/mysql/mysql_install/mysql-5.7.25-linux-glibc2.12-x86_64/share --daemonize --pid-file=/mysql/mysql_data/mysqld.pid $MYSQLD_OPTS 

# Use this to switch malloc implementation
EnvironmentFile=-/etc/sysconfig/mysql

# Sets open_files_limit
LimitNOFILE = infinity

Restart=on-failure

RestartPreventExitStatus=1

PrivateTmp=false
[root@localhost system]#

       警告：以上文件內容損壞後手動重建。

以下是顯示 mysqld 已準備好連接的警報日誌文件。

2019-03-27T11:28:13.334048Z 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
2019-03-27T11:28:13.335294Z 0 [Note] /mysql/mysql_install/mysql-5.7.25-linux-glibc2.12-x86_64/bin/mysqld (mysqld 5.7.25) starting as process 9309 ...
2019-03-27T11:28:13.337926Z 0 [Note] InnoDB: PUNCH HOLE support available
2019-03-27T11:28:13.337953Z 0 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
2019-03-27T11:28:13.337959Z 0 [Note] InnoDB: Uses event mutexes
2019-03-27T11:28:13.337964Z 0 [Note] InnoDB: GCC builtin __sync_synchronize() is used for memory barrier
2019-03-27T11:28:13.337969Z 0 [Note] InnoDB: Compressed tables use zlib 1.2.11
2019-03-27T11:28:13.337974Z 0 [Note] InnoDB: Using Linux native AIO
2019-03-27T11:28:13.338216Z 0 [Note] InnoDB: Number of pools: 1
2019-03-27T11:28:13.338317Z 0 [Note] InnoDB: Using CPU crc32 instructions
2019-03-27T11:28:13.339746Z 0 [Note] InnoDB: Initializing buffer pool, total size = 128M, instances = 1, chunk size = 128M
2019-03-27T11:28:13.351813Z 0 [Note] InnoDB: Completed initialization of buffer pool
2019-03-27T11:28:13.353463Z 0 [Note] InnoDB: If the mysqld execution user is authorized, page cleaner thread priority can be changed. See the man page of setpriority().
2019-03-27T11:28:13.365875Z 0 [Note] InnoDB: Highest supported file format is Barracuda.
2019-03-27T11:28:13.380701Z 0 [Note] InnoDB: Creating shared tablespace for temporary tables
2019-03-27T11:28:13.380772Z 0 [Note] InnoDB: Setting file './ibtmp1' size to 12 MB. Physically writing the file full; Please wait ...
2019-03-27T11:28:13.417750Z 0 [Note] InnoDB: File './ibtmp1' size is now 12 MB.
2019-03-27T11:28:13.418493Z 0 [Note] InnoDB: 96 redo rollback segment(s) found. 96 redo rollback segment(s) are active.
2019-03-27T11:28:13.418503Z 0 [Note] InnoDB: 32 non-redo rollback segment(s) are active.
2019-03-27T11:28:13.418713Z 0 [Note] InnoDB: Waiting for purge to start
2019-03-27T11:28:13.472045Z 0 [Note] InnoDB: 5.7.25 started; log sequence number 2524297
2019-03-27T11:28:13.472824Z 0 [Note] InnoDB: Loading buffer pool(s) from /mysql/mysql_data/ib_buffer_pool
2019-03-27T11:28:13.473297Z 0 [Note] Plugin 'FEDERATED' is disabled.
2019-03-27T11:28:13.474439Z 0 [Note] InnoDB: Buffer pool(s) load completed at 190327 16:58:13
2019-03-27T11:28:13.478030Z 0 [Warning] Failed to set up SSL because of the following SSL library error: SSL context is not usable without certificate and private key
2019-03-27T11:28:13.478659Z 0 [Note] Server hostname (bind-address): '*'; port: 3306
2019-03-27T11:28:13.478711Z 0 [Note] IPv6 is available.
2019-03-27T11:28:13.478724Z 0 [Note]   - '::' resolves to '::';
2019-03-27T11:28:13.478745Z 0 [Note] Server socket created on IP: '::'.
2019-03-27T11:28:13.489601Z 0 [Note] Event Scheduler: Loaded 0 events
2019-03-27T11:28:13.489791Z 0 [Note] **/mysql/mysql_install/mysql-5.7.25-linux-glibc2.12-x86_64/bin/mysqld: ready for connections.**
Version: '5.7.25'  socket: '/mysql/mysql_data/mysql.sock'  port: 3306  MySQL Community Server (GPL)

我已經嘗試了兩次相同的程序，但遇到了同樣的問題。顯示systemctl status mysqld.service“啟動（開始）”並且不返回提示。我可以登錄到數據庫。

從您的輸出：

ExecStart=…mysqld … –pid-file=/mysql/mysql_data/mysqld.pid …

…與您要求 systemd 觀看的內容不匹配：

PIDFile= /usr/local/mysql/data/mysqld.pid

糾正這兩個中的一個，你會變得更好。

引用自：https://unix.stackexchange.com/questions/508961