By default, the Handler uses File-Based Session Storage, so it stores incoming and outgoing messages and session's state data in files in the StorageDirectory folder.
However, it is possible to keep all session-related data in memory using the Memory-Based Session Storage.
Also, one can use Asynchronous File-based Session Storage, which combines excellent performance with the File-Based Session Storage functionality.
Yet another option is to use the Pluggable Session Storage.
Restoring Session State
When the Session object is created, the session state (Uuid, Negotiated, InSeqNum, OutSeqNum, PreviousSeqNo, PreviousUuid, etc.) is restored from the session storage.
To start a session as a new one (so-called "clean start"), either remove the session storage files from the previous runs or call the Reset(Boolean) method.
When the session is finished, the session storage files are not needed anymore. They can be backed up,
and later a new iLink 3 session with a new UUID will start message sequence numbers from
The usual practice is to back up log files at the end of the business week (so-called "End Of Week
procedure") to generate a new UUID and start the sequence numbers from
1 at the beginning of the next week.