不能摆脱：错误2002（HY000）：不能通过套接字'/var/run/mysqld/mysqld.sock'连接到本地MySQL服务器（2）

我知道这里有很多这样的问题，但是我没有find答案。

所以我有一个生产服务器运行几个数据库的几个网站。 我有一些性能问题，所以我编辑了mysqld.cnf文件，然后尝试重新启动Mysql，但它给了我一个错误：

Job for mysql.service failed because the control process exited with error code. See "systemctl status mysql.service" and "journalctl -xe" for details.

在那里看不到任何具体的细节。 所以我试图运行： mysql和我得到这个错误消息：

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 ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2) 

我现在已经更换所有的默认设置，然后更改我的mysqld.cnf，但我仍然得到相同的错误。

我也检查是否有任何MySQL服务正在运行，但没有。 而/var/run/mysqld/文件夹是空的。 我已经尝试用相应的名称创build一些空文件，但没有运气。

这里有什么问题，我怎么能安全地恢复它？ 我的网站目前正在离线…

编辑1 – mysqld.cnf：

 # # The MySQL database server configuration file. # # You can copy this to one of: # - "/etc/mysql/my.cnf" to set global options, # - "~/.my.cnf" to set user-specific options. # # One can use all long options that the program supports. # Run program with --help to get a list of available options and with # --print-defaults to see which it would actually understand and use. # # For explanations see # http://dev.mysql.com/doc/mysql/en/server-system-variables.html # This will be passed to all mysql clients # It has been reported that passwords should be enclosed with ticks/quotes # escpecially if they contain "#" chars... # Remember to edit /etc/mysql/debian.cnf when changing the socket location. # Here is entries for some specific programs # The following values assume you have at least 32M ram [client] socket=/var/run/mysqld/mysqld.sock [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 # # Instead of skip-networking the default is now to listen only on # localhost which is more compatible and is not less secure. bind-address = localhost # # * Fine Tuning # key_buffer_size = 16M max_allowed_packet = 16M thread_stack = 192K thread_cache_size = 8 # This replaces the startup script and checks MyISAM tables if needed # the first time they are touched myisam-recover-options = BACKUP #max_connections = 100 #table_cache = 64 #thread_concurrency = 10 # # * Query Cache Configuration # #query_cache_limit = 1M #query_cache_size = 16M query_cache_type = 1 query_cache_limit = 256K query_cache_min_res_unit = 2k query_cache_size = 80M # # * Logging and Replication # # Both location gets rotated by the cronjob. # Be aware that this log type is a performance killer. # As of 5.1 you can enable the log at runtime! #general_log_file = /var/log/mysql/mysql.log #general_log = 1 # # Error log - should be very few entries. # log_error = /var/log/mysql/error.log # # Here you can see queries with especially long duration log_slow_queries = /var/log/mysql/mysql-slow.log #long_query_time = 2 #log-queries-not-using-indexes # # The following can be used as easy to replay backup logs or for replication. # note: if you are setting up a replication slave, see README.Debian about # other settings you may need to change. #server-id = 1 #log_bin = /var/log/mysql/mysql-bin.log expire_logs_days = 10 max_binlog_size = 100M #binlog_do_db = include_database_name #binlog_ignore_db = include_database_name # # * InnoDB # # InnoDB is enabled by default with a 10MB datafile in /var/lib/mysql/. # Read the manual for more InnoDB related options. There are many! # # * Security Features # # Read the manual, too, if you want chroot! # chroot = /var/lib/mysql/ # # For generating SSL certificates I recommend the OpenSSL GUI "tinyca". # # ssl-ca=/etc/mysql/cacert.pem # ssl-cert=/etc/mysql/server-cert.pem # ssl-key=/etc/mysql/server-key.pem innodb_buffer_pool_size = 4G # (adjust value here, 50%-70% of total RAM) innodb_log_file_size = 128M 

编辑2： – 错误消息

 ● mysql.service - MySQL Community Server Loaded: loaded (/lib/systemd/system/mysql.service; enabled; vendor preset: enabled) Active: activating (start-post) (Result: exit-code) since Wed 2017-11-15 15:41:40 CET; 20s ago Process: 15879 ExecStart=/usr/sbin/mysqld (code=exited, status=1/FAILURE) Process: 15871 ExecStartPre=/usr/share/mysql/mysql-systemd-start pre (code=exited, status=0/SUCCESS) Main PID: 15879 (code=exited, status=1/FAILURE); : 15880 (mysql-systemd-s) Tasks: 2 Memory: 344.0K CPU: 305ms CGroup: /system.slice/mysql.service └─control ├─15880 /bin/bash /usr/share/mysql/mysql-systemd-start post └─15933 sleep 1 

错误日志：

 2017-11-15T15:05:16.045938Z 0 [Warning] Changed limits: max_open_files: 1024 (requested 5000) 2017-11-15T15:05:16.046016Z 0 [Warning] Changed limits: table_open_cache: 431 (requested 2000) 2017-11-15T15:05:16.201843Z 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details). 2017-11-15T15:05:16.202956Z 0 [Note] /usr/sbin/mysqld (mysqld 5.7.18-0ubuntu0.16.04.1) starting as process 20323 ... 2017-11-15T15:05:16.207200Z 0 [Note] InnoDB: PUNCH HOLE support available 2017-11-15T15:05:16.207231Z 0 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins 2017-11-15T15:05:16.207237Z 0 [Note] InnoDB: Uses event mutexes 2017-11-15T15:05:16.207242Z 0 [Note] InnoDB: GCC builtin __atomic_thread_fence() is used for memory barrier 2017-11-15T15:05:16.207248Z 0 [Note] InnoDB: Compressed tables use zlib 1.2.8 2017-11-15T15:05:16.207253Z 0 [Note] InnoDB: Using Linux native AIO 2017-11-15T15:05:16.207509Z 0 [Note] InnoDB: Number of pools: 1 2017-11-15T15:05:16.207622Z 0 [Note] InnoDB: Using CPU crc32 instructions 2017-11-15T15:05:16.209148Z 0 [Note] InnoDB: Initializing buffer pool, total size = 4G, instances = 8, chunk size = 128M 2017-11-15T15:05:16.468993Z 0 [Note] InnoDB: Completed initialization of buffer pool 2017-11-15T15:05:16.507282Z 0 [Note] InnoDB: If the mysqld execution user is authorized, page cleaner thread priority can be changed. See the man page of setpriority(). 2017-11-15T15:05:16.519181Z 0 [Note] InnoDB: Highest supported file format is Barracuda. 2017-11-15T15:05:16.622208Z 0 [Note] InnoDB: Creating shared tablespace for temporary tables 2017-11-15T15:05:16.622289Z 0 [Note] InnoDB: Setting file './ibtmp1' size to 12 MB. Physically writing the file full; Please wait ... 2017-11-15T15:05:16.655372Z 0 [Note] InnoDB: File './ibtmp1' size is now 12 MB. 2017-11-15T15:05:16.656333Z 0 [Note] InnoDB: 96 redo rollback segment(s) found. 96 redo rollback segment(s) are active. 2017-11-15T15:05:16.656352Z 0 [Note] InnoDB: 32 non-redo rollback segment(s) are active. 2017-11-15T15:05:16.656693Z 0 [Note] InnoDB: Waiting for purge to start 2017-11-15T15:05:16.706890Z 0 [Note] InnoDB: 5.7.18 started; log sequence number 66730045680 2017-11-15T15:05:16.707227Z 0 [Note] InnoDB: Loading buffer pool(s) from /var/lib/mysql/ib_buffer_pool 2017-11-15T15:05:16.707400Z 0 [Note] Plugin 'FEDERATED' is disabled. 2017-11-15T15:05:16.707618Z 0 [Note] InnoDB: Buffer pool(s) load completed at 171115 16:05:16 2017-11-15T15:05:16.710592Z 0 [ERROR] unknown variable 'log_slow_queries=/var/log/mysql/mysql-slow.log' 2017-11-15T15:05:16.710608Z 0 [ERROR] Aborting 2017-11-15T15:05:16.710615Z 0 [Note] Binlog end 2017-11-15T15:05:16.710657Z 0 [Note] Shutting down plugin 'validate_password' 2017-11-15T15:05:16.710669Z 0 [Note] Shutting down plugin 'ngram' 2017-11-15T15:05:16.710673Z 0 [Note] Shutting down plugin 'ARCHIVE' 2017-11-15T15:05:16.710677Z 0 [Note] Shutting down plugin 'BLACKHOLE' 2017-11-15T15:05:16.710681Z 0 [Note] Shutting down plugin 'partition' 2017-11-15T15:05:16.710684Z 0 [Note] Shutting down plugin 'MyISAM' 2017-11-15T15:05:16.710694Z 0 [Note] Shutting down plugin 'MRG_MYISAM' 2017-11-15T15:05:16.710698Z 0 [Note] Shutting down plugin 'CSV' 2017-11-15T15:05:16.710702Z 0 [Note] Shutting down plugin 'PERFORMANCE_SCHEMA' 2017-11-15T15:05:16.710735Z 0 [Note] Shutting down plugin 'INNODB_SYS_VIRTUAL' 2017-11-15T15:05:16.710739Z 0 [Note] Shutting down plugin 'INNODB_SYS_DATAFILES' 2017-11-15T15:05:16.710742Z 0 [Note] Shutting down plugin 'INNODB_SYS_TABLESPACES' 2017-11-15T15:05:16.710745Z 0 [Note] Shutting down plugin 'INNODB_SYS_FOREIGN_COLS' 2017-11-15T15:05:16.710749Z 0 [Note] Shutting down plugin 'INNODB_SYS_FOREIGN' 2017-11-15T15:05:16.710752Z 0 [Note] Shutting down plugin 'INNODB_SYS_FIELDS' 2017-11-15T15:05:16.710755Z 0 [Note] Shutting down plugin 'INNODB_SYS_COLUMNS' 2017-11-15T15:05:16.710758Z 0 [Note] Shutting down plugin 'INNODB_SYS_INDEXES' 2017-11-15T15:05:16.710762Z 0 [Note] Shutting down plugin 'INNODB_SYS_TABLESTATS' 2017-11-15T15:05:16.710765Z 0 [Note] Shutting down plugin 'INNODB_SYS_TABLES' 2017-11-15T15:05:16.710768Z 0 [Note] Shutting down plugin 'INNODB_FT_INDEX_TABLE' 2017-11-15T15:05:16.710771Z 0 [Note] Shutting down plugin 'INNODB_FT_INDEX_CACHE' 2017-11-15T15:05:16.710774Z 0 [Note] Shutting down plugin 'INNODB_FT_CONFIG' 2017-11-15T15:05:16.710777Z 0 [Note] Shutting down plugin 'INNODB_FT_BEING_DELETED' 2017-11-15T15:05:16.710781Z 0 [Note] Shutting down plugin 'INNODB_FT_DELETED' 2017-11-15T15:05:16.710784Z 0 [Note] Shutting down plugin 'INNODB_FT_DEFAULT_STOPWORD' 2017-11-15T15:05:16.710787Z 0 [Note] Shutting down plugin 'INNODB_METRICS' 2017-11-15T15:05:16.710790Z 0 [Note] Shutting down plugin 'INNODB_TEMP_TABLE_INFO' 2017-11-15T15:05:16.710793Z 0 [Note] Shutting down plugin 'INNODB_BUFFER_POOL_STATS' 2017-11-15T15:05:16.710796Z 0 [Note] Shutting down plugin 'INNODB_BUFFER_PAGE_LRU' 2017-11-15T15:05:16.710799Z 0 [Note] Shutting down plugin 'INNODB_BUFFER_PAGE' 2017-11-15T15:05:16.710802Z 0 [Note] Shutting down plugin 'INNODB_CMP_PER_INDEX_RESET' 2017-11-15T15:05:16.710805Z 0 [Note] Shutting down plugin 'INNODB_CMP_PER_INDEX' 2017-11-15T15:05:16.710809Z 0 [Note] Shutting down plugin 'INNODB_CMPMEM_RESET' 2017-11-15T15:05:16.710822Z 0 [Note] Shutting down plugin 'INNODB_CMPMEM' 2017-11-15T15:05:16.710826Z 0 [Note] Shutting down plugin 'INNODB_CMP_RESET' 2017-11-15T15:05:16.710830Z 0 [Note] Shutting down plugin 'INNODB_CMP' 2017-11-15T15:05:16.710833Z 0 [Note] Shutting down plugin 'INNODB_LOCK_WAITS' 2017-11-15T15:05:16.710836Z 0 [Note] Shutting down plugin 'INNODB_LOCKS' 2017-11-15T15:05:16.710839Z 0 [Note] Shutting down plugin 'INNODB_TRX' 2017-11-15T15:05:16.710842Z 0 [Note] Shutting down plugin 'InnoDB' 2017-11-15T15:05:16.710893Z 0 [Note] InnoDB: FTS optimize thread exiting. 2017-11-15T15:05:16.711042Z 0 [Note] InnoDB: Starting shutdown... 2017-11-15T15:05:16.811280Z 0 [Note] InnoDB: Dumping buffer pool(s) to /var/lib/mysql/ib_buffer_pool 2017-11-15T15:05:16.811522Z 0 [Note] InnoDB: Buffer pool(s) dump completed at 171115 16:05:16 2017-11-15T15:05:18.415398Z 0 [Note] InnoDB: Shutdown completed; log sequence number 66730045699 2017-11-15T15:05:18.417886Z 0 [Note] InnoDB: Removed temporary tablespace data file: "ibtmp1" 2017-11-15T15:05:18.417914Z 0 [Note] Shutting down plugin 'MEMORY' 2017-11-15T15:05:18.417924Z 0 [Note] Shutting down plugin 'sha256_password' 2017-11-15T15:05:18.417930Z 0 [Note] Shutting down plugin 'mysql_native_password' 2017-11-15T15:05:18.418176Z 0 [Note] Shutting down plugin 'binlog' 2017-11-15T15:05:18.418335Z 0 [Note] /usr/sbin/mysqld: Shutdown complete