Data checkpointing with DAGDA

DAGDA allows the SeD administrator to choose a file where DAGDA will store all the data that it manages. When a SeD has a configured valid path name to a backup file ("dataBackupFile" option in the configuration file), a client can ask to the agents or SeDs DAGDA components to save the data.

The dagda_save_platform() function, which can only be called from a client, records all the data managed by the agents or SeDs DAGDA components that allow it.
Then, the "restoreOnStart" configuration file option asks to the DAGDA component to restore the data stored on the "dataBackupFile" file when the component starts. This mechanism allows to stop the DIET platform for a while and to restart it conserving the same data distribution.