...
One of the most important concepts of Delft-FEWS is that always the latest forecast data is available to be used. In a typical operational Delft-FEWS forecasting system, new data is constantly imported, while older data is no longer relevant and can be removed. For a lot of database tables in fews master-controller database, the rows (records) in the database have a an expiryTime column specifying when the data can be removed. The removal is done by the so-called RollingBarrel process. It will remove any data for which the expiry time is exceeded.
...
If an expiryTime is defined at the TimeSeriesSet level, the time series blobs will get this expiry time, no matter what the workflow says.
If the timeseries is of an external type, the timeseries will also stay accessible. If a time series is of the simulated type, data access has to go through a query where the taskrun record plays a major role. This taskrun record expirytime is defined by the workflow. If the taskrun record is removed, the simulated data has become orphan as it has become inaccessible.
Preserving taskrun information
Timeseries in the database without taskruns are referred to as "orphaned timeseries". Note that simulated timeseries are not meaningful without taskrun information and should never be orphaned. Only external timeseries can be orphaned, but without taskruns they can not be amalgamated (merged) any more. In order to preserve taskruns longer than the default, the taskruns expirytime should be increased.
Expiry time for thresholdEvents
...
An edit of a task in the Admin Interface will update the taskproperties.xml to the value in <taskruns expiredays="..."/> setting.
Preserving taskrun information
Timeseries in the database without taskruns are referred to as "orphaned timeseries". Note that simulated timeseries are not meaningful without taskrun information and should never be orphaned. Only external timeseries can be orphaned, but without taskruns they can not be amalgamated (merged) any more. In order to preserve taskruns longer than the default, the taskruns expirytime should be increased.