SLI_OPEN Hang When Inappropriate LUA_INIT_TYPE is Used

• Microsoft SNA Server for Windows NT, versions 2.0, 2.1, 2.11 and 3.0

SUMMARY

An SLI_OPEN call may hang when it is issued on an SNA Server client machine and the lua_init_type specified in the SLI_OPEN is not appropriate for the host's session startup behavior. For example, if SLI_OPEN is called using an lua_init_type of LUA_INIT_TYPE_PRIM, and the host doesn't send an BIND message when the session is started, the SLI_OPEN will hang.

MORE INFORMATION

The SLI_OPEN call handles the SNA session startup with the host. Because the host may be configured to support different session startup methods, the SLI_OPEN call allows the following lua_init_type options to be used to accommodate this:

   LUA_INIT_TYPE_SEC_IS: Secondary with INITSELF command.
   LUA_INIT_TYPE_SEC_LOG: Secondary with an unformatted LOGON message
   LUA_INIT_TYPE_PRIM: Primary waiting for a BIND command
   LUA_INIT_TYPE_PRIM_SSCP: Primary with SSCP access

If the host sends a message on the SSCP-LU session but does not send a BIND, the SLI_OPEN call will hang if the LUA_INIT_TYPE_PRIM is used.

There are several possible solutions to this problem:

• The application could issue the type of SLI_OPEN that gives access to the SSCP-LU session (such as LUA_INIT_TYPE_PRIM_SSCP). Then, the application could write the logon message, and see the host's response. It could then parse the host's response, and act according to what it sees.

  -or-

• The application could be written to use the LUA RUI interface instead of SLI. This would give it access to all the flows to and from the host.

  -or-

• The application could implement a timer and cancel the SLI_OPEN if it does not complete after a certain time. However, this will not tell you why the SLI_OPEN may have hung.

• SNA Application internal, LUA API and 3270 message traces, (enabled where the SLI application is running).
• SNA Server DLC and 3270 message tracing (on the server)

If you are using a Win32 application under Windows NT, SNATRACE can also be used to capture SNA Application tracing.

If you are using a Win16 application, see Q123256 for instructions on enabling SNA Server Win16 client tracing.