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FIX Adapter System Administration

Resetting Message Sequence Numbers

Overview

TT strongly recommends that persistent FIX sessions be reset weekly. Failure to follow this recommendation can lead to abnormally large FIX cache files that can severely impact performance.

Ways to reset sequence numbers for persistent FIX sessions

The following methods can be used to reset the message sequence numbers in a persistent FIX session:

  • During failover scenarios only, FIX clients can send a Logon (A) message with Tag 34 (MsgSeqNum) = 1 and Tag 141 (ResetSeqNumFlag) = Y.
  • You can issue the FIXAdapter.exe -r command from a Windows command prompt.
  • You can issue the sessionreset command from a telnet session.

From a Windows command prompt

If the TT FIX Adapter is not running, you can use the FIXAdapter.exe -r command-line option to reset the sequence numbers for a particular persistent FIX session.

To reset the message sequence number from a command prompt:

  1. Open a Windows command window.
  2. Type: FIXAdapter.exe -r LocalCompId -RemoteCompIdnum1num2, where:
    • LocalCompId and RemoteCompId represent the session IDs to reset
    • num1 and num2 represent the optional new message sequence numbers

For example, suppose your configuration defines the following session information:

  • LocalCompId=FAOrder
  • RemoteCompID=ClientApp

If you enter the command, FIXadapter.exe -r FAOrder-ClientApp 48 100, the sequence numbers reset as follows:

  • Outgoing Tag 34 (MsgSeqNum) for session FAOrder-ClientApp to 48
  • Incoming Tag 34 (MsgSeqNum) for session FAOrder-ClientApp to 100

If you enter the command, FIXadapter.exe -r FAOrder-ClientApp, it sets both the incoming and outgoing message sequence numbers to 0.

Notes:

  • TT recommends that you do not use the -r option without a sessionName parameter unless TT Support instructs you to do so.
  • TT also recommends that you reset all persistent FIX session sequence numbers at the end of each week as follows:

    FIXAdapter.exe -r *-*

From a telnet session

You can reset the message sequence number of a particular persistent FIX session while the TT FIX Adapter is running by using the sessionreset command through a telnet session.

Note: Before you reset the message sequence numbers for a FIX client using this method, make sure that the FIX client is not logged into TT FIX Adapter.

To reset the message sequence number using telnet:

  1. Open a Windows command window.
  2. Type: telnet ipaddress port, where:
    • ipaddress is the IP address of the machine that hosts the TT FIX Adapter whose message sequence numbers you want to reset.
    • port is the administrative port number specified in the FACT Administrator Port option for the TT FIX Adapter configuration.
  3. Type: sessionreset /local:LocalCompId /remote:RemoteCompId, where:
    • LocalCompId equals the LocalCompId of the session to reset
    • RemoteCompId matches the RemoteCompId of the session to reset

You can also reset all FIX sessions through a telnet connection, as follows:

sessionreset /local:* /remote:*