@luxiangyuan

Basically, the OMM message structure, it has a seqNum attribute in the message header. However, this attribute is managed by the server side (feed/exchange) and EMA does not generate the seqNum. Please note that some exchanges increase the value by 2 or by 16.

For EMA C++, you can verify whether or not the RefreshMsg or UpdateMsg contains sequence number by calling method hasSeqNum() and then get the sequence number by calling method getSeqNum(). Below is sample codes to get the sequence number from Refresh message.

if (refreshMsg.hasSeqNum())
{
  cout << endl << "Sequence Number:" << refreshMsg.getSeqNum() << endl;
}

If this as described "this attribute is managed by the server side (feed/exchange) and EMA does not generate the seqNum" is there another similar mechanism but handled directly by EMA?
(Eg:timestamp, Ema's seqNum, ecc)

Hi @cdefusco

Our realtime APIs are 'content neutral' and pass the data to your callbacks as they are received from the server / provider and therefore don't add additional information such as Sequence Number / Timestamp etc.