Question

我正在尝试将自动增量列添加到mysql表中，如下所示：

mysql> ALTER TABLE scraped_comments ADD row_id INT NOT NULL AUTO_INCREMENT PRIMARY KEY;

该表中大约有1500万条记录。查询运行大约一个半小时，然后以错误结束：

错误2013（HY000）：查询期间与MySQL服务器的连接丢失

我尝试通过编辑/etc/mysql/mysql.conf.d/mysqld.cnf设置更高的超时值

wait_timeout = 31536000
Interactive_timeout = 31536000

，然后再次运行查询。但是错误仍然存在。当查询运行时，我认为问题可能是由较少的内存引起的，因此我在另一个终端中打开了htop，但使用的内存不足一半。

我检查了/var/log/mysql/error.log文件，并在该文件中找到以下内容：

    ...  
InnoDB: ###### Diagnostic info printed to the standard error stream
2019-06-14T06:21:49.965496Z 0 [ERROR] [MY-012872] [InnoDB] Semaphore wait has lasted > 38632704 seconds. We intentionally crash the server because it appears to be hung.[FATAL] Semaphore wait has lasted > 600 seconds. We intentionally crash the server because it appears to be hung.  
2019-06-14T06:21:49.965563Z 0 [ERROR] [MY-013183] [InnoDB] Assertion failure: ut0ut.cc:629 thread 140385843095296  
InnoDB: We intentionally generate a memory trap.  
InnoDB: Submit a detailed bug report to http://bugs.mysql.com.  
InnoDB: If you get repeated assertion failures or crashes, even  
InnoDB: immediately after the mysqld startup, there may be  
InnoDB: corruption in the InnoDB tablespace. Please refer to  
InnoDB: http://dev.mysql.com/doc/refman/8.0/en/forcing-innodb-recovery.html  
InnoDB: about forcing recovery.  
06:21:49 UTC - mysqld got signal 6 ;  
Most likely, you have hit a bug, but this error can also be caused by malfunctioning hardware.  
Thread pointer: 0x0  
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 = 0 thread_stack 0x46000  
/usr/sbin/mysqld(my_print_stacktrace(unsigned char*, unsigned long)+0x3d) [0x1dc2f5d]  
/usr/sbin/mysqld(handle_fatal_signal+0x351) [0xeee441]  
/lib/x86_64-linux-gnu/libpthread.so.0(+0x11390) [0x7fae50d4f390]  
/lib/x86_64-linux-gnu/libc.so.6(gsignal+0x38) [0x7fae4f241428]  
/lib/x86_64-linux-gnu/libc.so.6(abort+0x16a) [0x7fae4f24302a]  
/usr/sbin/mysqld(ut_dbg_assertion_failed(char const*, char const*, unsigned long)+0x2db) [0x20736cb]  
/usr/sbin/mysqld(ib::fatal::~fatal()+0x18e) [0x2075afe]  
/usr/sbin/mysqld(srv_error_monitor_thread()+0xc07) [0x200ccf7]  
/usr/sbin/mysqld(std::thread::_Impl<std::_Bind_simple<Runnable (void (*)())> >::_M_run()+0x63) [0x1e6e543]  
/usr/lib/x86_64-linux-gnu/libstdc++.so.6(+0xb8c80) [0x7fae4fbadc80]  
/lib/x86_64-linux-gnu/libpthread.so.0(+0x76ba) [0x7fae50d456ba]  
/lib/x86_64-linux-gnu/libc.so.6(clone+0x6d) [0x7fae4f31341d]  
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.  
2019-06-14T06:21:53.867586Z 0 [System] [MY-010116] [Server] /usr/sbin/mysqld (mysqld 8.0.16) starting as process 6199  
2019-06-14T06:21:58.097227Z 0 [System] [MY-010229] [Server] Starting crash recovery...  
2019-06-14T06:21:58.114311Z 0 [System] [MY-010232] [Server] Crash recovery finished.  
2019-06-14T06:21:59.096291Z 0 [Warning] [MY-010068] [Server] CA certificate ca.pem is self signed.  
2019-06-14T06:21:59.225066Z 0 [System] [MY-010931] [Server] /usr/sbin/mysqld: ready for connections. Version: '8.0.16'  socket: '/var/run/mysqld/mysqld.sock'  port: 3306  MySQL Community Server - GPL.  
2019-06-14T06:21:59.436191Z 0 [System] [MY-011323] [Server] X Plugin ready for connections. Socket: '/var/run/mysqld/mysqlx.sock' bind-address: '::' port: 33060  
...

感谢您的帮助

Answer 1

跨越
MySQL: InnoDb: Semaphore wait has lasted > 600 seconds. We intentionally crash the server

并增加了thread_cache_size，innodb_buffer_pool_size和table_open_cache。我想这个问题是由于innodb_buffer_size造成的，因为我第一次尝试使用2 GB的innodb_buffer_size无效。然后将其增加到3 GB，查询成功完成

ALTER TABLE：错误2013（HY000）：查询期间与MySQL服务器的连接丢失

1 个答案: