無法通過套接字'/var/run/mysqld/mysqld.sock'（2）連接到本地MySQL服務器（錯誤2002）

Question

我知道這是一個經常被問到的問題，但是我似乎無法從其他主題中找到任何解決方案。

我嘗試過的

• 重新安裝mysql服務器（不是客戶端）
• chown mysql:mysql /var/lib/mysql
• 簽出my.cnf似乎一切正確的地方
• 將bind-address更改為localhost

• 在某些時候，似乎我沒有套接字文件，

  sudo find / -type s | grep mysqld.sock sudo find / -type s | grep mysqld.sock沒有給出任何結果。

  ---

編輯

我現在輸入mysql_config --socket ，似乎現在在/var/run/mysqld/mysqld.sock處有一個套接字文件。

還檢查了apparmor_status ，結果如下：

apparmor module is loaded.
14 profiles are loaded.
14 profiles are in enforce mode.
   /sbin/dhclient
   /usr/bin/evince
   /usr/bin/evince-previewer
   /usr/bin/evince-previewer//sanitized_helper
   /usr/bin/evince-thumbnailer
   /usr/bin/evince-thumbnailer//sanitized_helper
   /usr/bin/evince//sanitized_helper
   /usr/lib/NetworkManager/nm-dhcp-client.action
   /usr/lib/connman/scripts/dhclient-script
   /usr/lib/cups/backend/cups-pdf
   /usr/sbin/cups-browsed
   /usr/sbin/cupsd
   /usr/sbin/mysqld
   /usr/sbin/tcpdump
0 profiles are in complain mode.
3 processes have profiles defined.
0 processes are in enforce mode.
0 processes are in complain mode.
3 processes are unconfined but have a profile defined.
   /sbin/dhclient (1089) 
   /usr/sbin/cups-browsed (1415) 
   /usr/sbin/cupsd (16608) 

在所有這些/etc/init.d/mysql start仍然失敗

my.cnf中的設置

[client]
port        = 3306
socket      = /var/run/mysqld/mysqld.sock

# Here is entries for some specific programs
# The following values assume you have at least 32M ram

# This was formally known as [safe_mysqld]. Both versions are currently parsed.
[mysqld_safe]
socket      = /var/run/mysqld/mysqld.sock
nice        = 0

[mysqld]
#
# * Basic Settings
#
user        = mysql
pid-file    = /var/run/mysqld/mysqld.pid
socket      = /var/run/mysqld/mysqld.sock
port        = 3306
basedir     = /usr
datadir     = /var/lib/mysql
tmpdir      = /tmp
lc-messages-dir = /usr/share/mysql
skip-external-locking

---

我簽出了/var/log/error.log ，當我嘗試# /etc/init.d/mysql start ，從日志中顯示以下報告：

150528 22:58:19 [Warning] Using unique option prefix key_buffer instead of key_buffer_size is deprecated and will be removed in a future release. Please use the full name instead.
150528 22:58:19 [Warning] Using unique option prefix key_buffer instead of key_buffer_size is deprecated and will be removed in a future release. Please use the full name instead.
150528 22:58:19 [Note] /usr/sbin/mysqld (mysqld 5.5.43-0ubuntu0.14.04.1) starting as process 14608 ...
150528 22:58:19 [Warning] Using unique option prefix myisam-recover instead of myisam-recover-options is deprecated and will be removed in a future release. Please use the full name instead.
150528 22:58:19 [Warning] Using unique option prefix myisam-recover instead of myisam-recover-options is deprecated and will be removed in a future release. Please use the full name instead.
150528 22:58:19 [Note] Plugin 'FEDERATED' is disabled.
/usr/sbin/mysqld: Can't find file: './mysql/plugin.frm' (errno: 13)
150528 22:58:19 [ERROR] Can't open the mysql.plugin table. Please run mysql_upgrade to create it.
150528 22:58:19 InnoDB: The InnoDB memory heap is disabled
150528 22:58:19 InnoDB: Mutexes and rw_locks use GCC atomic builtins
150528 22:58:19 InnoDB: Compressed tables use zlib 1.2.8
150528 22:58:19 InnoDB: Using Linux native AIO
150528 22:58:19 InnoDB: Initializing buffer pool, size = 128.0M
150528 22:58:19 InnoDB: Completed initialization of buffer pool
150528 22:58:19 InnoDB: highest supported file format is Barracuda.
150528 22:58:19  InnoDB: Waiting for the background threads to start
150528 22:58:20 InnoDB: 5.5.43 started; log sequence number 140421610
150528 22:58:20 [Note] Server hostname (bind-address): 'localhost'; port: 3306
150528 22:58:20 [Note]   - 'localhost' resolves to '127.0.0.1';
150528 22:58:20 [Note] Server socket created on IP: '127.0.0.1'.
150528 22:58:20 [ERROR] /usr/sbin/mysqld: Can't find file: './mysql/host.frm' (errno: 13)
150528 22:58:20 [ERROR] Fatal error: Can't open and lock privilege tables: Can't find file: './mysql/host.frm' (errno: 13)
150528 22:58:20 mysqld_safe mysqld from pid file /var/run/mysqld/mysqld.pid ended

有人能幫我解決問題而又不丟失數據庫的問題嗎

Answer 1

您的mysql安裝已完成：

150528 22:58:20 [ERROR] /usr/sbin/mysqld: Can't find file: './mysql/host.frm' (errno: 13)

它不是一開始就沒有啟動，因此沒有套接字文件。 您從內部/核心mysql數據庫中丟失了數據，這是一個非常糟糕的信號。

Answer 2

如果尚未初始化數據目錄，現在是在啟動mysqld之前對其進行初始化的時候了。

您可以運行mysql提供的這兩個腳本之一。 在您的shell提示符下，將它們運行為：

# mysql_secure_installation

要么

# mysql_install_db --user=mysql \
         --basedir=<path to mysql install dir> \
         --datadir=/var/lib/mysql/data

mysql_install_db將使用--bootstrap和--skip-grant-tables選項調用mysqld 。

Answer 3

mysql_install_db cmd可以解決問題。 我又有了一個套接字，現在可以再次登錄mysql了。