Fault Tolerance

exit_on_error

Parameter description: If this function is enabled, errors of the ERROR level will be escalated to PANIC errors, and core stacks will be generated. It is mainly used to locate problems and test services.

This is a USERSET parameter. Set it based on instructions provided in Table 2.

Value range: Boolean

• on: Errors of the ERROR level will be escalated to PANIC errors.
• off: Errors of the ERROR level will not be escalated.

Default value: off

restart_after_crash

Parameter description: If this parameter is set to on and a backend process crashes, GaussDB automatically reinitializes the backend process.

This is a SIGHUP parameter. Set it based on instructions provided in Table 2.

Value range: Boolean

• on: The availability of the database is maximized.

  In some circumstances (for example, when a management tool, such as xCAT, is used to manage GaussDB), setting this parameter to on maximizes the availability of the database.

• off: A management tool is enabled to obtain control permission and take proper measures when a backend process crashes.

Default value: on

omit_encoding_error

Parameter description: If this parameter is set to on and the client character set of the database is encoded in UTF-8 format, character encoding conversion errors will be recorded in logs. Additionally, converted characters that have conversion errors will be ignored and replaced with question marks (?).

This is a USERSET parameter. Set it based on instructions provided in Table 2.

Value range: Boolean

• on: Characters with conversion errors will be ignored and replaced with question marks (?), and error information will be recorded in logs.
• off: Characters with conversion errors cannot be converted and error information will be directly displayed.

Default value: off

max_query_retry_times

This parameter has been discarded in the current version.

cn_send_buffer_size

Parameter description: Specifies the size of the data buffer used for data transmission on the primary database node.

This is a POSTMASTER parameter. Set it based on instructions provided in Table 2.

Value range: an integer ranging from 8 to 128. The unit is KB.

Default value: 8KB

data_sync_retry

Parameter description: Specifies whether to keep running the database when updated data fails to be written into disks by using the fsync function. In some OSs, no error is reported even if fsync fails after the second attempt. As a result, data is lost.

This is a POSTMASTER parameter. Set it based on instructions provided in Table 2.

Value range: Boolean

• on: The database keeps running and fsync is called again after fsync fails to synchronize data to the disk.
• off: A PANIC-level error is reported and the database is stopped after fsync fails.

Default value: off

remote_read_mode

Parameter description: Specifies whether to enable the remote read function. This function allows pages on the standby node to be read when reading pages on the primary node fails.

This is a POSTMASTER parameter. Set it based on instructions provided in Table 1.

Value range: enumerated values

• off indicates that the remote read function is disabled.
• non_authentication indicates that the remote read function is enabled but certificate authentication is not required.
• authentication indicates that the remote read function is enabled and certificate authentication is required.

Default value: authentication