You can learn about defaults that VMware Tanzu SQL with MySQL for VMs applies to its Percona Server components.
Learn about the server defaults for Tanzu SQL for VMs service plans. Most of the server defaults are the same for all service plans, however, some server defaults differ depending on the service plan.
For server defaults that are:
- Common to all plans, see Server defaults for all plans.
- Specific to single node and leader-follower plans, see Server defaults for single node and leader-follower plans.
- Specific to highly available (HA) cluster plans, see Server defaults for highly available cluster lans.
- Specific to multi‑site replication plans, see Server defaults for Multi‑Site Replication plans.
You can use optional parameters to change certain server defaults. For more information, see Changing Defaults Using Arbitrary Parameters.
Server defaults for all plans
The following table lists the Tanzu SQL for VMs server defaults that are common to all service plans:
| Name | Variable Name | Default | Notes |
|---|---|---|---|
| Applier Threads | wsrep_slave_threads |
Number of CPU cores | Defines the number of threads to use when applying write-sets. For more information, see the Percona XtraDB Cluster documentation. This property can be overriden using a arbitrary parameter, or reset to the default (Number of CPU cores) by setting an arbitrary parameter value of -1. |
| Audit Log | audit-log |
OFF | To set to ON, select Enable Server Activity Logging in Monitoring. Logs are written in JSON to /var/vcap/store/mysql_audit_logs/mysql_server_audit.log. |
| Space Limit for Binary Logs | binlog_space_limit |
33% of the disk space on each service instance if Limit binary log disk use is selected. | For more information, see Configuring MySQL and the Percona blog site. If Limit binary log disk use is not selected, then no space limit is applied. |
| Character Set | character-set-server |
utf8 |
This setting defaults all character sets. You can override this during a session. |
| Binary Log Removal | expire_log_days |
3 | This setting is the number of days before binary log files are automatically removed. For more information, see the MySQL documentation. |
| InnoDB Transaction Log Durability | innodb_flush_log_at_trx_commit |
1 | At each transaction commit, logs are written and flushed to disk. For more information, see the MySQL documentation. |
| InnoDB Flush Method | innodb_flush_method |
fsync |
This setting defines the method used to flush data to InnoDB data and log files. For more information, see the MySQL documentation. |
| InnoDB Auto Increment Lock Mode | innodb-autoinc-lock-mode |
2 | This setting uses the interleaved mode. This enables multiple statements to execute at the same time. There can be gaps in auto-incrementing columns. |
| InnoDB Buffer Pool Size | innodb-buffer-pool-size |
50% of the available memory on each service instance | This setting is dynamically configured to be 50% of the available memory on each service instance. |
| InnoDB Log Buffer Size | innodb-log-buffer-size |
32 MB | This setting defaults to 32 MB to avoid excessive disk I/O when issuing large transactions. |
| Log Bin Trust Function Creators | log-bin-trust-function-creators |
ON | This setting relaxes constraints on how MySQL writes stored procedures to the binary log. For more information, see the MySQL documentation. |
| Lower Case Table Names | lower-case-table-names |
0 | By default, all table names are case sensitive. Operators can change this default setting on the MySQL Configuration page and permit developers to override the default when they create a service instance. For more information about using lowercase table names, see the MySQL documentation. |
| Max Allowed Packet | max-allowed-packet |
256 MB | If necessary, you can change this size setting in a session variable. |
| Max Size Allowed for Binary Logs | max_binlog_size default |
~1/3 of the Space Limit for Binary Logs if Limit binary log disk use is selected. | For more information, see Configuring MySQL and Percona documentation. If Limit binary log disk use is not selected, then no maximum is set. |
| Reverse Name Resolution | skip-name-resolve |
ON | This deactivates reverse DNS lookups to improve performance. Tanzu SQL for VMs uses user credentials, rather than hostnames, to authenticate access. Therefore, most deployments do not need reverse DNS lookups. To activate reverse name resolution, deselect this option. |
| Skip Symbolic Links | symbolic-links |
OFF | Tanzu SQL for VMs is configured to prevent the use of symlinks to tables. VMware recommends this security setting to prevent users from manipulating files on the server file system. For more information, see Making MySQL secure against attackers. |
| Table Definition Cache | table-definition-cache |
8192 | For information about changing this setting, see the MySQL documentation. |
Server defaults for single node and leader-follower plans
In addition to the server default settings that are common to all plans, single node and leader-follower plans use the server defaults listed in the following table:
| Name | Variable Name | Default | Notes |
|---|---|---|---|
| Max Connections | max-connections |
5000 connections per service instance | System processes count towards this limit. |
| MyISAM Recover Options | myisam-recover-options |
BACKUP, FORCE | This setting enables Tanzu SQL for VMs to recover from most MyISAM problems without human intervention. For more information, see the MySQL documentation. |
| Event Scheduler | event-scheduler |
ON | Tanzu SQL for VMs enables the event scheduler so users can create and use events in their dedicated service instances. |
| InnoDB Log File Size | innodb-log-file-size |
256 MB | Tanzu SQL for VMs clusters default to a log-file size of 256 MB. |
| Collation Server | collation-server |
utf8_general_ci |
You can override this during a session. For instructions about viewing available and default collations, see the MySQL documentation. |
| Relay Log Recovery | relay-log-recovery |
ON |
When enabled, relay log recovery happens automatically after server startup. For more information, see the MySQL documentation. |
Server defaults for highly available cluster plans
In addition to the server default settings that are common to all plans, HA cluster plans use the server defaults listed in the following table:
| Name | Variable Name | Default | Notes |
|---|---|---|---|
| Max Connections | max-connections |
5000 connections per service instance | System processes count towards this limit. |
| MyISAM Recover Options | myisam-recover-options |
OFF | This setting enables Tanzu SQL for VMs to recover from most MyISAM problems without human intervention. For more information, see the MySQL documentation. |
| Event Scheduler | event-scheduler |
OFF | Tanzu SQL for VMs enables the event scheduler so users can create and use events in their dedicated service instances. |
| InnoDB Log File Size | innodb-log-file-size |
1024 MB | Tanzu SQL for VMs clusters default to a log-file size of 256 MB. |
| Collation Server | collation-server |
utf8_unicode_ci |
You can override this during a session. For instructions about viewing available and default collations, see the MySQL documentation. |
| Relay Log Recovery | relay-log-recovery |
ON |
When enabled, relay log recovery happens automatically after server startup. For more information, see the MySQL documentation. |
Server defaults for Multi‑Site Replication plans
In addition to the server default settings that are common to all plans, multi‑site replication plans use the server defaults listed in the following table.
| Name | Variable Name | Default | Notes |
|---|---|---|---|
| Max Connections | max-connections |
5000 connections per service instance | System processes count towards this limit. |
| MyISAM Recover Options | myisam-recover-options |
OFF | This setting activates Tanzu SQL for VMs to recover from most MyISAM problems without human intervention. For more information, see the MySQL documentation. |
| Event Scheduler | event-scheduler |
OFF | Tanzu SQL for VMs activates the event scheduler so users can create and use events in their dedicated service instances. |
| InnoDB Log File Size | innodb-log-file-size |
1024 MB | Tanzu SQL for VMs clusters default to a log-file size of 256 MB. |
| Collation Server | collation-server |
utf8_unicode_ci |
You can override this setting during a session. For instructions about viewing available and default collations, see the MySQL documentation. |
| Relay Log Recovery | relay-log-recovery |
OFF |
When enabled, relay log recovery happens automatically after server startup. For more information, see the MySQL documentation. |
