• Data Warehouse Service

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  2. Data Warehouse Service
  3. Developer Guide
  4. Setting Configuration Parameters
  5. Appendix B: GUC Parameter Description
  6. Transaction Monitoring

Transaction Monitoring

The automatic rollback transaction can be monitored and its statement problems can be located by setting the transaction timeout warning. In addition, the statements with long execution time can also be monitored.

transaction_sync_naptime

Parameter description: For data consistency, when the local transaction's status differs from that of in the snapshot of GTM, other transactions will be blocked. You need to wait for a few minutes until the transaction status of the local host is consistent with that of the GTM. The gs_clean tool is automatically triggered for cleansing when the waiting period on the CN exceeds that of transaction_sync_naptime. The tool will shorten the blocking time after it completes the cleansing.

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

Value range: an integer. The minimum value is 0 and the unit is s.

Default value30s

NOTE:

If the value of this parameter is set to 0gs_clean will not be automatically invoked for the cleansing before the blocking arrives the duration. Instead, the gs_clean tool is invoked by gs_clean_timeout. The default value is 5 minutes.

transaction_sync_timeout

Parameter description: For data consistency, when the local transaction's status differs from that of in the snapshot of GTM, other transactions will be blocked. You need to wait for a few minutes until the transaction status of the local host is consistent with that of the GTM. An exception is reported when the waiting duration on the CN exceeds the value of transaction_sync_timeout. Roll back the transaction to avoid the blocking to the system due to sync lock and long time hang.

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

Value range: an integer. The minimum value is 0 and the unit is s.

Default value10min

NOTE:

If this value is set to 0, no error is reported when the blocking times out or the transaction is rolled back.

The value of this parameter should be greater than gs_clean_timeout. If it is smaller, unnecessary transaction rollback will probably occur due to a block timeout caused by residual transactions on a DN that have not been deleted using gs_clean.