Re: [Quickfix-users] Session restarts

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

Brian,

Have you tried adding these scenarios to the unit tests?  Were the =
results normal?

--oren
  ----- Original Message -----=20
  From: Brian Erst=20
  To: qui...@li...=20
  Sent: Tuesday, April 04, 2006 12:08 PM
  Subject: [Quickfix-users] Session restarts


  We're seeing some very odd session resets since the switch to DST.

  Using QuickFIX 1.9.4 (it's a production environment, so we're a few =
releases back), I've got the following settings:

  ConnectionType=3Dacceptor
  StartDay=3DSunday
  StartTime=3D00:05:00
  EndDay=3DSaturday
  EndTime=3D23:45:00
  MillisecondsInTimeStamp=3DY
  ResetOnLogout=3DN
  ResetOnDisconnect=3DN

  At 2006/04/03-00:00:00 UMT (5am Chicago time -5 UMT), all our =
connections reset. Our sessions were completely reset - the socket was =
dropped ("Dropped connection"), the sequence numbers were reset and we =
had all sorts of problems reconnecting (our clients attempted to =
reconnect, but our sequence numbers were now back to "1" and the logon =
response (resend sequence) had too low of a sequence number, causing the =
other side to drop us). Just when our operations staff got everything =
back in sync, the same thing happened at 01:00:00 UMT.

  The session then stayed up all day until, you guessed it, 00:00:00 UMT =
on the 4th. All sessions were dropped and reset, we struggled to get =
things back up and at 01:00:00, it happened again. Needless to say, I'm =
not the most popular man in the organization today.

  I've looked at the Session, SessionTime, SessionState and FileStore =
code to try to track what's going on. I suspect that for some =
unexplained reason we're triggering a session reset because =
checkSessionTime() in Session.h is returning false. My guess is that =
we're resetting twice because the first time, the "current" time is =
failing (00:00:00 UMT) and the second time the "session creation time" =
(inside the .session file) is "00:00:00". Upon the creation of the =
second session, the .session creation time is 01:00:00 and we're safe =
until the "real time" is 00:00:00.

  The problem is - I can't figure out why this is happening. I've gone =
thru the SessionTime code, running the code thru my head with the =
appropriate values and everything SEEMS okay, but obviously something is =
wrong.

  As far as I can tell, last night I should have called =
isSameSession(00:00:05, 23:45:00, 1, 7, 2006/04/04-00:00:00, =
2006/04/03:01:00:00) - which should have returned "true" but seems to =
have returned "false". I can't figure out why - the code is a little =
overly complicated (I can tell there are some buggy parts of 1.9.4's =
session time code - which shouldn't be triggered with these values) but =
it looks OK with these values.

  Further data point - prior to DST switch, this all worked. We've been =
running the exact same code and configuration for months with no =
problems. The only reason I mention DST is the coincidence that it would =
have first been exercised Monday morning, the problem is time related =
and it's only happened since then (and consistently every night).

  Ideas or suggestions?

  - Brian Erst
  Thynk Software, Inc.