SLI_OPEN Hang When Inappropriate LUA_INIT_TYPE is Used (131787)


The information in this article applies to:

  • Microsoft SNA Server 2.0
  • Microsoft SNA Server 2.1
  • Microsoft SNA Server 2.11
  • Microsoft SNA Server 3.0
  • Microsoft SNA Server 4.0
This article was previously published under Q131787

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

These options are described in the Microsoft SNA Server LUA Programmer's Guide.

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.
If you believe the application is using the correct lua_init_type, although it is continuing to exhibit SLI_OPEN hang problems, the following SNA Server trace information should be provided to SNA Server support personnel:
  • 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)
SNA Server DLC and 3270 message tracing can be dynamically enabled and disabled using SNATRACE. Trace files are generated in text format in <SNAROOT>\TRACES\*.TRC.

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 123256 for instructions on enabling SNA Server Win16 client tracing.
Modification Type:MinorLast Reviewed:3/8/2005
Keywords:kbnetwork kbprogramming KB131787
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