Notes for modifying innodb_data_file_path parameter in mysql
Explain
In the test environment, the service is initialized and started without setting too many detailed parameters. In the later optimization process, it is found that the innodb_data_file_path setting is too small:
root@node1 14:59: [(none)]> show variables like '%innodb_data_file_path%'; +-----------------------+------------------------+ | Variable_name | Value | +-----------------------+------------------------+ | innodb_data_file_path | ibdata1:12M:autoextend | +-----------------------+------------------------+ 1 row in set (0.00 sec) root@node1 14:59: [(none)]>
When innodb_data_file_path is not configured, the default innodb_data_file_path = ibdata1:12M:autoextend
[mysqld] innodb_data_file_path = ibdata1:12M:autoextend
When you need to change it to 1G, you can't change ibdata1 to 1G directly in the configuration file.
[mysqld] innodb_data_file_path = ibdata1:1G:autoextend
Otherwise, when the service is started, the following error message can be seen from the error log:
2019-03-29T06:47:32.044316Z 0 [ERROR] InnoDB: The Auto-extending innodb_system data file './ibdata1' is of a different size 768 pages (rounded down to MB) than specified in the .cnf file: initial 65536 pages, max 0 (relevant if non-zero) pages!
In general, the size of ibdata1 is not 65536 pages * 16KB / 1024KB = 1G, but 786 pages * 16KB / 1024KB = 12M.
Method 1: Recommendation
Instead, add another ibdata2:1G, as follows:
[mysqld] innodb_data_file_path = ibdata1:12M;ibdata2:1G:autoextend
Restart the database!
Method 2: No recommendation
Change it directly to the following
[mysqld] innodb_data_file_path = ibdata1:1G:autoextend
You can delete ibdata1, ib_logfile 0, ib_logfile 1 files in the $mysql_datadir directory:
rm -f ibdata* ib_logfile*
MySQL can also be started, but the following error will be reported in the MySQL error log:
2019-03-29T07:10:47.844560Z 0 [Warning] Could not increase number of max_open_files to more than 5000 (request: 65535) 2019-03-29T07:10:47.844686Z 0 [Warning] Changed limits: table_open_cache: 1983 (requested 2000) 2019-03-29T07:10:48.028262Z 0 [Warning] 'NO_AUTO_CREATE_USER' sql mode was not set. 2019-03-29T07:10:48.147653Z 0 [Warning] InnoDB: Cannot open table mysql/plugin from the internal data dictionary of InnoDB though the .frm file for the table exists. Please refer to http://dev.mysql.com/doc/refman/5.7/en/innodb-troubleshooting.html for how to resolve the issue. mysqld: Table 'mysql.plugin' doesn't exist 2019-03-29T07:10:48.147775Z 0 [ERROR] Can't open the mysql.plugin table. Please run mysql_upgrade to create it. 2019-03-29T07:10:48.163444Z 0 [Warning] InnoDB: Cannot open table mysql/gtid_executed from the internal data dictionary of InnoDB though the .frm file for the table exists. Please refer to http://dev.mysql.com/doc/refman/5.7/en/innodb-troubleshooting.html for how to resolve the issue. mysqld: Table 'mysql.gtid_executed' doesn't exist 2019-03-29T07:10:48.163502Z 0 [Warning] Gtid table is not ready to be used. Table 'mysql.gtid_executed' cannot be opened. 2019-03-29T07:10:48.163658Z 0 [Warning] InnoDB: Cannot open table mysql/gtid_executed from the internal data dictionary of InnoDB though the .frm file for the table exists. Please refer to http://dev.mysql.com/doc/refman/5.7/en/innodb-troubleshooting.html for how to resolve the issue. mysqld: Table 'mysql.gtid_executed' doesn't exist 2019-03-29T07:10:48.163711Z 0 [Warning] Gtid table is not ready to be used. Table 'mysql.gtid_executed' cannot be opened. 2019-03-29T07:10:48.164619Z 0 [Warning] Failed to set up SSL because of the following SSL library error: SSL context is not usable without certificate and private key 2019-03-29T07:10:48.166805Z 0 [Warning] InnoDB: Cannot open table mysql/server_cost from the internal data dictionary of InnoDB though the .frm file for the table exists. Please refer to http://dev.mysql.com/doc/refman/5.7/en/innodb-troubleshooting.html for how to resolve the issue. 2019-03-29T07:10:48.166891Z 0 [Warning] Failed to open optimizer cost constant tables 2019-03-29T07:10:48.168072Z 0 [Warning] InnoDB: Cannot open table mysql/time_zone_leap_second from the internal data dictionary of InnoDB though the .frm file for the table exists. Please refer to http://dev.mysql.com/doc/refman/5.7/en/innodb-troubleshooting.html for how to resolve the issue. 2019-03-29T07:10:48.168165Z 0 [Warning] Can't open and lock time zone table: Table 'mysql.time_zone_leap_second' doesn't exist trying to live without them 2019-03-29T07:10:48.169454Z 0 [Warning] InnoDB: Cannot open table mysql/servers from the internal data dictionary of InnoDB though the .frm file for the table exists. Please refer to http://dev.mysql.com/doc/refman/5.7/en/innodb-troubleshooting.html for how to resolve the issue. 2019-03-29T07:10:48.169527Z 0 [ERROR] Can't open and lock privilege tables: Table 'mysql.servers' doesn't exist 2019-03-29T07:10:48.170042Z 0 [Warning] InnoDB: Cannot open table mysql/slave_master_info from the internal data dictionary of InnoDB though the .frm file for the table exists. Please refer to http://dev.mysql.com/doc/refman/5.7/en/innodb-troubleshooting.html for how to resolve the issue. 2019-03-29T07:10:48.170617Z 0 [Warning] InnoDB: Cannot open table mysql/slave_relay_log_info from the internal data dictionary of InnoDB though the .frm file for the table exists. Please refer to http://dev.mysql.com/doc/refman/5.7/en/innodb-troubleshooting.html for how to resolve the issue. 2019-03-29T07:10:48.170946Z 0 [Warning] InnoDB: Cannot open table mysql/slave_master_info from the internal data dictionary of InnoDB though the .frm file for the table exists. Please refer to http://dev.mysql.com/doc/refman/5.7/en/innodb-troubleshooting.html for how to resolve the issue. 2019-03-29T07:10:48.171046Z 0 [Warning] Info table is not ready to be used. Table 'mysql.slave_master_info' cannot be opened. 2019-03-29T07:10:48.171272Z 0 [Warning] InnoDB: Cannot open table mysql/slave_worker_info from the internal data dictionary of InnoDB though the .frm file for the table exists. Please refer to http://dev.mysql.com/doc/refman/5.7/en/innodb-troubleshooting.html for how to resolve the issue. 2019-03-29T07:10:48.171626Z 0 [Warning] InnoDB: Cannot open table mysql/slave_relay_log_info from the internal data dictionary of InnoDB though the .frm file for the table exists. Please refer to http://dev.mysql.com/doc/refman/5.7/en/innodb-troubleshooting.html for how to resolve the issue. 2019-03-29T07:10:48.171688Z 0 [Warning] Info table is not ready to be used. Table 'mysql.slave_relay_log_info' cannot be opened.