Re: [Quickfix-developers] Recovering from client side sequence number amnesia

[Oren M. <or...@qu...>]

Dale,

You can ask the session object for the expected sequence numbers.

http://www.quickfixengine.org/quickfix/doc/html/class_f_i_x_1_1_session.h=
tml#a27

--oren
  ----- Original Message -----=20
  From: Dale Wilson=20
  To: qui...@li...=20
  Sent: Tuesday, May 24, 2005 12:53 PM
  Subject: [Quickfix-developers] Recovering from client side sequence =
number amnesia


Due to some network problems, I may (or may not) have managed to send =
this message yesterday.   Please forgive it if it's a duplicate.

Dale

Hi QuickFIX developers,

I think I've run into a "you-can't-get-there-from-here" problem, but I'd =
like to be sure I'm not missing something.

The situation I'm trying to handle happens when the client (initiator) =
is recovering from a significant failure and has lost track of the =
sequence number expected by the server (acceptor).  The client sends =
logon message a sequence number that is less than the one expected by =
the server.  The server responds, correctly, with a logout message.  If =
the server is based on QuickFIX this logout message will contain a Text =
field giving the expected sequence number.=20

   i.e.: 58=3DMsgSeqNum too low, expecting 7 but received 1

What I would like to do is detect this Logout message; inform the user =
of the situation; and allow them to verity that the sequence number =
should be reset.

Unfortunately as far as I have been able to determine, the Logout =
message containig the expected sequence number never reaches the =
application code.  QuickFIX determines that this is not a valid sequence =
of messages:

  [Session::verify calls Session::validLogonState and throws an =
exception when it returns false. ]=20

and calls Application::onLogout()  (twice, actually, but who's =
counting.) The body of the message containing the expected sequence =
number isn't available vis the onLogout call -- so I can't find a way to =
determine what sequence number is expected.

My work around for this will be to read the log, identify the logout =
message, and parse it to find the expected sequence number -- unless, of =
course, someone tells me that there's a better way.

Any suggestions would be appreciated,

Dale

  --=20
  -----------------------------------------------------
  Dale Wilson, Senior Software Engineer=20
  Object Computing, Inc. (OCI)
  http://www.ociweb.com/ http://www.theaceorb.com/
  ----------------------------------------------------