SLI_CLOSE May Hang if CICS Doesn't Respond to SHUTC

• Microsoft SNA Server, versions 3.0, 3.0SP1, 3.0SP2, 4.0

SYMPTOMS

When an SLI application calls SLI_CLOSE, the SLI_CLOSE may never complete if the host sends an UNBIND request but fails to send a SHUTC response.

This problem was found when connecting an SLI application to CICS. If the CICS region is stopped and started, in some cases the SLI application's SLI_CLOSE request failed to complete.

The following API and message sequence summarizes the failure scenario:

SLI Program  SLI API      SNA Server/Host
===========  =========    =================
  < SLI program in session with the host >

                          <- SHUTD
             <- SLI_BID (LUA_SESSION_END_REQUESTED)

             SHUTD +RSP ->
             CHASE ->
                          <- CHASE +RSP
             SHUTC ->
                          <- UNBIND (type 01 = normal)
             SENSE 08390000 ->
                          UNBIND +RSP ->

CAUSE

The SLI interface was hanging if it received an UNBIND when waiting for a SHUTC response.

STATUS

Microsoft has confirmed this to be a problem in SNA Server version 3.0, 3.0 Service Pack 1 (SP1), 3.0 SP2, and 4.0.

A supported fix is now available, but has not been fully regression-tested and should be applied only to systems experiencing this specific problem. Unless you are severely impacted by this specific problem, Microsoft recommends that you wait for the next Service Pack that contains this fix. Contact Microsoft Product Support Services for more information.

MORE INFORMATION

With this update applied, the SLI interface will now complete the SLI_CLOSE if an UNBIND is received, even if no SHUTC response is received.

Keywords          : kbbug3.00 kbbug3.00.sp1 prodsna snalua snaprog kbbug3.00.sp2 kbbug4.00
Version           : WINDOWS:3.0,3.0SP1,3.0SP2,4.0
Platform          : WINDOWS
Issue type        : kbbug
Solution Type     : kbfix