Each iLink 3 session is represented with a unique 64-bit identifier (UUID). CME Group recommends using the system timestamp, which represents the number of microseconds since epoch (Jan 1, 1970) as the timestamp. Business messages received from the exchange are recoverable for the sequence number + UUID combination.

The OnixS::CME::iLink3::Session automatically generates the UUID in the following cases:

A new OnixS::CME::iLink3::Session object is created, and the value from the previous run cannot be restored from the session storage.
The OnixS::CME::iLink3::Session::reset method is called.

One can pass a UUID value manually to the OnixS::CME::iLink3::Session::Session constructor.

To read the UUID value, use the OnixS::CME::iLink3::Session::uuid() const method.

For example:

std::clog << session.uuid() << std::endl;

More details about UUID can be found in the Universally Unique Identifier (UUID) article.

Re-Setting UUID

To reset the UUID intra-session on the same trading day, use the OnixS::CME::iLink3::Session::reset(bool startOfWeek=false) method.

To reset the UUID before the first connection of the week (so-called "Weekly Reset"), use the OnixS::CME::iLink3::Session::reset(bool startOfWeek=true) method.

Note: The OnixS::CME::iLink3::Session::reset method can be called only when the session is disconnected.

See also: Restoring Session State; Scheduling Sessions for Automatic Connection