log_archive_concurrency

Description

log_archive_concurrency specifies the concurrency level of log archiving.

Privilege requirements

• Query the parameter

  The sys tenant and all user tenants can query this parameter by using the SHOW PARAMETERS statement or the GV$OB_PARAMETERS view.

• Modify the parameter

  The sys tenant and user tenants can modify this parameter.

Attributes

Considerations

The number of log archiving threads is calculated based on the adaptive value of the max_cpu parameter of the tenant. The calculation rules are as follows:

• If the max_cpu value of the tenant is less than or equal to 8, the number of log archiving threads is equal to the max_cpu value.
• If the max_cpu value of the tenant is greater than 8 and less than 32, the number of log archiving threads is equal to the max_cpu value divided by 2, with a minimum value of 8.
• If the max_cpu value of the tenant is greater than 32, the number of log archiving threads is equal to the max_cpu value divided by 4, with a minimum value of 16.

Examples

• The sys tenant modifies the log archiving concurrency level of the MySQL tenant. The following example shows how to do this:

  obclient> ALTER SYSTEM SET log_archive_concurrency = 5 tenant = 'mysql';
  

• A MySQL tenant modifies its own log archiving concurrency level. The following example shows how to do this:

  obclient> ALTER SYSTEM SET log_archive_concurrency = 5;
  

References

For more information about log archiving parameters, see View log archiving parameters.