The likelihood of problems occurring
1, may be/opt/mysql/data/data directory MySQL user does not have permissions (modify the data directory permissions)
Workaround: Give permission, execute "chown-r mysql.mysql/opt/mysql/data" and restart Mysqld
2. The MySQL process may already exist in the process
WORKAROUND: Use the command "ps-ef|grep mysqld" To see if there is a mysqld process, kill with "kill-9 process number" and then restart mysqld!
3, may be the second time to install MySQL on the machine, there are residual data affect the start of the service.
Workaround: Go to the MySQL binary log directory to see if there is a mysql-binlog.index, and quickly delete it.
4. mysql will use the/ETC/MY.CNF configuration file when it is not specified at startup, please open this file to see if there is a specified data directory (DATADIR) under [mysqld].
WORKAROUND: Please set this line under [mysqld]: DataDir =/opt/mysql/data
5. skip-federated field Problem
Workaround: Check the/etc/my.cnf file for any skip-federated fields that have not been commented out, and if so, comment them out immediately.
6. Error log directory does not exist
Workaround: Use "Chown" "chmod" command to give MySQL owner and permissions
7, the disaster of SELinux, if it is a CentOS system, default will open SELinux
Workaround: Temporarily change to warning mode first: [[email protected]www php]# Setenforce 0
Then open the/etc/sysconfig/selinux and change the selinux=enforcing to selinux=disabled
Additional:
Experience:
One more reason may be:
Check the configuration file/usr/local/mysql/my.cnf There is no innodb_buffer_pool_size this parameter
Innodb_buffer_pool_size: The main role is to cache the index of the InnoDB table, data, buffer when inserting data;
Default value: 128M;
Dedicated MySQL server sets the size of this value: System memory is 70%-80% best.
If your system has little memory, look at this parameter and set it to a smaller value.
Summary:
Add error log parameters in configuration file/etc/my.cnf, all issues resolved
[Mysqld_safe]log-error =/data/mysql/logs/error.log
To view log information when an error is started:
#tail-F/data/mysql/logs/error.log 160721 06:12:07 Mysqld_safe starting mysqld daemon with databases From/data/mysql/dat a2016-07-21 06:12:10 0 [Warning] TIMESTAMP with implicit the DEFAULT value is deprecated. --explicit_defaults_for_timestamp server option (see documentation for more details). 2016-07-21 06:12:10 0 [not E]/opt/mysql/bin/mysqld (mysqld 5.6.27-log) starting as Process 2290 ... 2016-07-21 06:12:10 2290 [Note] Plugin ' Federated ' is disabled.2016-07-21 06:12:10 2290 [Warning] The option InnoDB (skip- INNODB) is deprecated and would be removed in a future release2016-07-21 06:12:10 2290 [Note] innodb:using Atomics to ref Count buffer pool pages2016-07-21 06:12:10 2290 [Note] innodb:the InnoDB memory heap is disabled2016-07-21 06:12:10 2290 [Note] Innodb:mutexes and Rw_locks use GCC atomic builtins2016-07-21 06:12:10 2290 [Note] innodb:memory barrier are not used2016 -07-21 06:12:10 2290 [note] innodb:compressed tables use zlib 1.2.32016-07-21 06:12:10 2290 [note] inNodb:using CPU crc32 instructions2016-07-21 06:12:10 2290 [Note] innodb:initializing buffer pool, size = 128.0m2016-07-2 1 06:12:10 2290 [note] innodb:completed initialization of buffer pool2016-07-21 06:12:10 2290 [note] Innodb:highest supp orted file format is barracuda.2016-07-21 06:12:11 2290 [Note] innodb:128 rollback segment (s) was active.2016-07-21 06:12 : 2290 [note] innodb:waiting for purge to start2016-07-21 06:12:11 2290 [note] innodb:5.6.27 started; Log sequence number 16259972016-07-21 06:12:11 2290 [ERROR]/opt/mysql/bin/mysqld:unknown option '--slave_parallel_ Workers=3 ' 2016-07-21 06:12:11 2290 [ERROR] aborting2016-07-21 06:12:11 2290 [Note] Binlog end2016-07-21 06:12:11 2290 [not E] Shutting plugin ' partition ' 2016-07-21 06:12:11 2290 [Note] shutting down plugin ' innodb_sys_datafiles ' 2016-07-21 0 6:12:11 2290 [note] shutting down plugin ' innodb_sys_tablespaces ' 2016-07-21 06:12:11 2290 [note] shutting down plugin ' INN Odb_sys_foreign_cols ' 2016-07-21 06:12:11 2290[Note] Shutting down plugin ' innodb_sys_foreign ' 2016-07-21 06:12:11 2290 [Note] shutting down plugin ' Innodb_sys_fields '
Discovery Log Output
2016-07-21 06:12:11 2290 [ERROR]/opt/mysql/bin/mysqld:unknown option '--slave_parallel_workers=3 ' 2016-07-21 06:12:11 2290 [ERROR] Aborting
This error parameter is definitely added to the config file, which can be removed.
new Add Error:
Starting mysql.171019 10:11:54 Mysqld_safe error:log-error set to '/data/tools/mysql/logs/error.log ', however file don ' t Exists. Create writable for user ' MySQL '.
This is a bug in MySQL new version: 5.6.35,5.6.36
Reference: https://bugs.mysql.com/bug.php?id=84427
Solve:
To create a log file manually:
Touch/data/tools/mysql/logs/error.logchown MySQL. /data/tools/mysql/logs/error.log/etc/init.d/mysqld start
Transferred from http://732233048.blog.51cto.com/9323668/1636409, the copyright belongs to the author.
MySQL startup times wrong: starting MySQL ... error! Workaround for the server quit without updating PID file (/opt/mysql/data/mysql.pid)