ExecId
which guarantees that events received from dual sessions can be deduplicated.
ExecId
of the last order event sent by the trading system to the client.ExecId
is less than LastExecId
in Last ExecId Request (35=F1), the client can either send an Event Resend Request (35=F3), or a session-level Resend Request (35=2) message to retrieve missed events.
Having recovered all missed events, the client can safely assume that any requests for which there was no corresponding event was either not processed by the trading system or was rejected.