Session Identifier

The idea is to give user ability to create several sessions with the same SenderCompId and TargetCompId and to give ability to address these session by unique ID. To achieve this goal, com.b2bits.FIXAntennaSessionId structure was introduced. The structure consists of three string properties - Sender, Target and Qualifier. Many of external methods still can be called with only SenderCompId and TargetCompId parameters. However, if user needs to create several sessions with the same SenderCompId/TargetCompId pair they first need to create com.b2bits.FIXAntennaSessionId structure by passing SenderCompId, TargetCompId and unique SessionQualifier to its constructor, and then call overloaded method which takes com.b2bits.FIXAntennaSessionId structure as one of arguments.

To establish several sessions with the same SenderCompId and TargetCompId, both Initiator and Acceptor should create several session objects which differ from each other by SessionQualifier property. SessionQualifier property on Initiator side must be the same as SessionQualifier property of the corresponding session on acceptor side. When Initiator connects to Acceptor, it sends SessionQualifier along with SenderCompId and TargetCompId in logon message. The SessionQualifier tag in logon message is optional and can be configured in engine.properties file. When Acceptor receives logon message with the SessionQualifier it searches for registered session with com.b2bits.FIXAntennaSessionId corresponding to received TargetCompId, SenderCompId and SessionQualifier. If the session is found it is associated with the incoming connection, otherwise connection is rejected

If user creates session by passing only SenderCompId and TargetCompId parameters (without SessionQualifier), the com.b2bits.FIXAntennaSessionId structure is created and stored internally with empty Qualifier property. If Acceptor registers a session without session qualifier it won't accept any incoming connection with session qualifier defined in logon message. And vice versa, if Acceptor has registered a session or several sessions with qualifiers, it won't accept connections from Initiators without SessionQualifier.

The FIX engine will automatically insert SessionQualifier tag into logon message if user creates session with qualifier on initiator side and SessionQualifier tag is appropriately configured in engine.properties. To configure SessionQualifier tag user needs to add the lines like below to config file -

Session.Default.LogonMessageSessionQualifierTag = 9012

The FIX engine will automatically insert SessionQualifier tag into logon User can also overload LogonMessageSessionQualifierTag property for any particular session like below

Session.Sender1/Target1.LogonMessageSessionQualifierTag = 9015

The FIX engine will automatically insert SessionQualifier tag into logon If user wish to define or overload some other properties for any session with session qualifier they can add a configuration line like in example below

Session.Sender1/Target1/Q1.StorageType=null

The FIX engine will automatically insert SessionQualifier tag into logon Wherever possible, if SessionQualifier is defined for a session, the string representation of the session's identifier will consist of Sender, Target and SessionQualifier (separated by a delimiter). If SessionQualifier qualifier is not defined, it will be omitted in any output related to session identifier. This is done for backward compatibility. The possible affected places are log files (names and content), admin protocol messages, keys of message storage and so on.