Preparing Amazon RDS for SQL server for backup and recovery
Qlik Replicate consumes changes captured from the database transaction log (TLOG). The TLOG is maintained by Amazon RDS for SQL Server for recovery purposes. All changes made to a database are written to the TLOG. The following happens when recovery is required:
- A backup copy of the database is made.
- Logged events are taken and used in a rolling-forward process where the recorded changes are replayed against that copy.
To prepare for backup and recovery you must make sure that the Amazon RDS for SQL Server Recovery Model is set up. This should be carried out by an Amazon RDS for SQL Server system administrator using the RDS management web interface.
The TLOG data is truncated as soon as it is no longer needed therefore the TLOG is not persistent. However, Qlik Replicate guaranteed delivery requires persistency in the changed data. To ensure persistency:
- A full database backup must be carried out before beginning to migrate data.
- The Recovery Model must be set to Bulk logged or Full.
After setting the Recovery Model, it is strongly recommended not to change it; doing so may result in loss of data.