这是我6个月前安装的数据库，运行良好。 这是目前运行在Ubuntu 12.04。 试图连接到MySQL导致此错误：
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (111)
然后：
$ sudo mysqld
它返回：
130702 15:38:54 [Note] Plugin 'FEDERATED' is disabled. 130702 15:38:54 InnoDB: The InnoDB memory heap is disabled 130702 15:38:54 InnoDB: Mutexes and rw_locks use GCC atomic builtins 130702 15:38:54 InnoDB: Compressed tables use zlib 1.2.3.4 130702 15:38:54 InnoDB: Initializing buffer pool, size = 128.0M 130702 15:38:54 InnoDB: Completed initialization of buffer pool 130702 15:38:54 InnoDB: highest supported file format is Barracuda. InnoDB: The log sequence number in ibdata files does not match InnoDB: the log sequence number in the ib_logfiles! 130702 15:38:54 InnoDB: Database was not shut down normally! InnoDB: Starting crash recovery. InnoDB: Reading tablespace information from the .ibd files... InnoDB: Restoring possible half-written data pages from the doublewrite InnoDB: buffer... 130702 15:38:55 InnoDB: Waiting for the background threads to start 130702 15:38:56 InnoDB: 1.1.8 started; log sequence number 5201901917 130702 15:38:56 [Note] Server hostname (bind-address): '127.0.0.1'; port: 3306 130702 15:38:56 [Note] - '127.0.0.1' resolves to '127.0.0.1'; 130702 15:38:56 [Note] Server socket created on IP: '127.0.0.1'. 130702 15:38:56 [Note] Event Scheduler: Loaded 0 events 130702 15:38:56 [Note] mysqld: ready for connections. Version: '5.5.28-0ubuntu0.12.04.3' socket: '/var/run/mysqld/mysqld.sock' port: 3306 (Ubuntu) 19:39:02 UTC - mysqld got signal 11 ; This could be because you hit a bug. It is also possible that this binary or one of the libraries it was linked against is corrupt, improperly built, or misconfigured. This error can also be caused by malfunctioning hardware. We will try our best to scrape up some info that will hopefully help diagnose the problem, but since we have already crashed, something is definitely wrong and this may fail. key_buffer_size=16777216 read_buffer_size=131072 max_used_connections=1 max_threads=151 thread_count=1 connection_count=1 It is possible that mysqld could use up to key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 346681 K bytes of memory Hope that's ok; if not, decrease some variables in the equation. Thread pointer: 0x7f9509e51530 Attempting backtrace. You can use the following information to find out where mysqld died. If you see no messages after this, something went terribly wrong... stack_bottom = 7f94f1d3de60 thread_stack 0x30000 mysqld(my_print_stacktrace+0x29)[0x7f95083427b9] mysqld(handle_fatal_signal+0x483)[0x7f9508209b43] /lib/x86_64-linux-gnu/libpthread.so.0(+0xfcb0)[0x7f9506f5bcb0] mysqld(+0x320e1c)[0x7f9508113e1c] mysqld(_ZN4JOIN15alloc_func_listEv+0x9c)[0x7f950812391c] mysqld(_ZN4JOIN7prepareEPPP4ItemP10TABLE_LISTjS1_jP8st_orderS7_S1_S7_P13st_select_lexP18st_select_lex_unit+0x918)[0x7f9508124658] mysqld(_Z12mysql_selectP3THDPPP4ItemP10TABLE_LISTjR4ListIS1_ES2_jP8st_orderSB_S2_SB_yP13select_resultP18st_select_lex_unitP13st_select_lex+0x130)[0x7f950812d060] mysqld(_Z13handle_selectP3THDP3LEXP13select_resultm+0x17c)[0x7f9508132fbc] mysqld(+0x2f6714)[0x7f95080e9714] mysqld(_Z21mysql_execute_commandP3THD+0x16d8)[0x7f95080f1178] mysqld(_Z11mysql_parseP3THDPcjP12Parser_state+0x10f)[0x7f95080f5e0f] mysqld(_Z16dispatch_command19enum_server_commandP3THDPcj+0x1380)[0x7f95080f7260] mysqld(_Z24do_handle_one_connectionP3THD+0x1bd)[0x7f950819b80d] mysqld(handle_one_connection+0x50)[0x7f950819b870] /lib/x86_64-linux-gnu/libpthread.so.0(+0x7e9a)[0x7f9506f53e9a] /lib/x86_64-linux-gnu/libc.so.6(clone+0x6d)[0x7f9506684cbd] Trying to get some variables. Some pointers may be invalid and cause the dump to abort. Query (7f94e0004b80): is an invalid pointer Connection ID (thread ID): 1 Status: NOT_KILLED The manual page at http://dev.mysql.com/doc/mysql/en/crashing.html contains information that should help you find out what is causing the crash.
我不知所措 还有哪些报告可以用来诊断呢？ /var/log/mysql.log是空的。
看来你已经成为一个正在进行的bug的受害者。
由于某些未知的原因， mysql.sock文件往往会在没有警告的情况下消失：
我已经多次处理这种情况，以下是我过去的文章：
Dec 14, 2012 ： Percona服务器超时在/etc/init.d/mysql启动 May 08, 2012 ： 如何在Mac OS X上正确停止MySQL服务器？ Feb 06, 2012 ： MySQL数据库和表丢失 解决方法是使用TCP / IP协议login到mysql。 只要你有：
[email protected]的MySQL用户 --protocol=tcp选项 skip-networking 你可以这样login到mysql：
mysql -uroot -h127.0.0.1 --protocol=tcp -p
如果你能做到这一点，那么closuresMySQL并启动它将修复它像这样：
mysqladmin -uroot -h127.0.0.1 --protocol=tcp -p shutdown service mysql start
这将带回文件mysql.sock 。 这就解释了为什么重启操作系统也解决了它。
回到这个问题，你input
sudo mysqld
MySQL已经在运行，你试图再次启动mysqld，因此这个奇怪的消息。