Date:         Tue, 12 May 1998 22:28:52 -0400
Reply-To:     CICS List <CICS-L@UGA.CC.UGA.EDU>
Sender:       CICS List <CICS-L@UGA.CC.UGA.EDU>
From:         "Dinh, Victor" <Victor.Dinh@CIBC.COM>
Subject:      Single Session LU6.2 Serialization
Content-Type: text/plain

         Date: 05/12/98
         From: Victor Dinh                                  DINH     -
MIC
           To: INTERNET GATEWAY                             INTERNET -
SCCB
      Subject: Single Session LU6.2 Serialization
    Reference: Note from (EX010898 - SCCB) attached below
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to: cics-l@uga.cc.uga.edu
 
George, I don't have clues, just some questions and comments.
 
Is there any entry with trace type KCP SUSPEND in your trace ?
Does CICS task for file xfer issue file I/O ? If it does, the
next task will get dispatched (or resumed), does some works
until it gets suspended,and the next task gets control, ...
 
BTW, I'm interested in a brief overview of the Tandem code that
does APPC to CICS. Would you please provide it to the CICS-L.
TIA,
victor.dinh@cibc.com
My own opinion, not CIBC's
-------------------------------- ATTACHED NOTE
--------------------------------
 
         Date: May 12, 1998
         From: George Sproull [SMTP:George_Sproull@FMSO.NA EX010898 -
SCCB
           To: CICS-L@UGA.CC.UGA.EDU                                -
      Subject: Single Session LU6.2 Serialization
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     Hi,
        For our home grown file xfer process, we define 20
single-session
     LU 6.2 connections using connection/session definition pairs. Each
     session uses the same modename. The file transfers are initiated on
     the foreign host (Tandem) and the file transfer process in CICS 2.1
     gets a session. A CEMT INQ CONN shows that all twenty connections
may
     be in an acquired status concurrently, and an equal number of
     iterations of the file transfer transaction show up on a CEMT INQ
     TASK. Our CICS is always the PLU, but the file transfer transaction
is
     invoked from the Tandem process.
        Everything seemed to be fine, until we happened to see a trace
that
     showed that on file transfers originating from the IBM system, the
     first would start (we would see data from the 1st transfer on the
     trace exclusively), another would start (at this point, no more
data
     would flow on the first session and we would see data from the
second
     exclusively), another would start (no more data from the 1st or 2nd
     sessions on the trace, only from session #3). When #3 completed, we
     would see only data from session #2. When it completed, #1 would
     resume and finally complete. File transfers coming from the Tandem
to
     the IBM have buffers from multiple transfers interspersed (as we
would
     expect).
        I'm confused, anyone have a clue? (we aren't interested in
     rewriting for parallel sessions...just curious). Actually
performance
     isn't bad either direction.
 
                                                Thanks in advance,
 
                                              George Sproull
                                              DISA SSO Mechanicsburg,PA
 
George_Sproull@fmso.navy.mil