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 thread crashes, GaussDB automatically reinitializes the backend thread.

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

Value range: Boolean

• on maximizes the availability of the database.

  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 indicates that a management tool is enabled to obtain control permission and take proper measures when a backend thread 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 indicates that characters that have conversion errors will be ignored and replaced with question marks (?), and error information will be recorded in logs.
• off indicates that characters that have conversion errors cannot be converted and error information will be directly displayed.

Default value: off

If this parameter is modified by running the gs_guc reload command and the connection of a session on the current node is not from the client but from another node in the cluster to which the node belongs, this parameter does not take effect immediately on the session after the gs_guc reload command is executed. The setting takes effect only after the connection node is disconnected and then reconnected.

cn_send_buffer_size

Parameter description: Specifies the size of the data buffer used for data transmission on CNs.

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 indicates that the database keeps running and fsync is executed again after fsync fails.
• off indicates that 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