DOCUMENT:Q311584 08-MAY-2002 [sna] TITLE :LUA App May Hang If VTAM Recycled While RUI_WRITE Outstanding PRODUCT :Microsoft SNA Server PROD/VER::4.0 OPER/SYS: KEYWORDS:kbDSupport sna4 kbsna400sp1 kbsna400sp2 kbsna400sp3 kbhis2000 kbhis2000bug kbsna400sp4 ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft SNA Server, version 4.0 - Microsoft Host Integration Server 2000 ------------------------------------------------------------------------------- SYMPTOMS ======== A logical unit application (LUA) application may stop responding ("hang") if it has an outstanding RUI_WRITE when Virtual Telecommunications Access Method (VTAM) is recycled on the IBM mainframe. This can occur when the RUI_WRITE was issued to send an INITSELF Request Unit (RU) to the host system. CAUSE ===== If VTAM is unavailable when an LUA application issues an RUI_WRITE(INITSELF) to an IBM mainframe, the INITSELF may not be responded to. Once VTAM is available, it may issue an ACTLU(ERP) to recover the session over which the LUA application was communicating. When this occurs, the Request Unit Interface (RUI) library (Winrui32.dll) does not return an error on the outstanding RUI_WRITE() verb when the host issues the ACTLU(ERP) to recover the session. The result is that the outstanding RUI_WRITE() verb never finishes, which may cause the LUA application to stop responding. RESOLUTION ========== SNA Server 4.0 No fix is available for this problem in SNA Server 4.0 at this time. Host Integration Server 2000 A supported fix is now available from Microsoft, but it is only intended to correct the problem described in this article and should be applied only to systems experiencing this specific problem. This fix may receive additional testing at a later time, to further ensure product quality. Therefore, if you are not severely affected by this problem, Microsoft recommends that you wait for the next Microsoft Host Integration Server 2000 service pack that contains this fix. To resolve this problem immediately, contact Microsoft Product Support Services to obtain the fix. For a complete list of Microsoft Product Support Services phone numbers and information about support costs, please go to the following address on the World Wide Web: http://support.microsoft.com/default.aspx?scid=fh;EN-US;CNTACTMS NOTE: In special cases, charges that are normally incurred for support calls may be canceled, if a Microsoft Support Professional determines that a specific update will resolve your problem. Normal support costs will apply to additional support questions and issues that do not qualify for the specific update in question. The English version of this fix should have the following file attributes or later: +-----------------------------------+ | File name | Date | Time | +-----------------------------------+ | Winrui32.dll | 01/25/2001 | 14:42 | +-----------------------------------+ NOTE: Because of file dependencies, the most recent fix that contains the above files may also contain additional files. NOTE: If this product was already installed on your computer when you purchased it from the Original Equipment Manufacturer (OEM) and you need this fix, please call the Pay Per Incident number listed on the above Web site. If you contact Microsoft to obtain this fix, and if it is determined that you only require the fix you requested, no fee will be charged. However, if you request additional technical support, and if your no-charge technical support period has expired, or if you are not eligible for standard no-charge technical support, you may be charged a non-refundable fee. For more information about eligibility for no-charge technical support, see the following article in the Microsoft Knowledge Base: Q154871 Determining If You Are Eligible for No-Charge Technical Support STATUS ====== SNA Server 4.0 Microsoft has confirmed this to be a problem in Microsoft SNA Server version 4.0,. Host Integration Server 2000 Microsoft has confirmed this to be a problem in Microsoft Host Integration Server 2000. MORE INFORMATION ================ The following is an example of a scenario that can result in the problem described in this article: +-------------------------------------------------------------------+ | LUA Application | SNA/HIS 2000 Server | Host | +-------------------------------------------------------------------+ | RUI_WRITE(INITSELF) -> | | | +-------------------------------------------------------------------+ | | INITSELF -> | | +-------------------------------------------------------------------+ | | | <- ACTLU(ERP) | +-------------------------------------------------------------------+ | | ACTLU +RSP -> | | +-------------------------------------------------------------------+ | | NOTIFY(SLU Enabled) -> | | +-------------------------------------------------------------------+ | | <- FMIST(LU Reactivated) | | +-------------------------------------------------------------------+ The IBM mainframe doesn't respond to the INITSELF because VTAM is not available. Once VTAM is available, it sends an ACTLU(ERP) to recover the session. The SNA Server service (Snaservr.exe) responds to the ACTLU(ERP) with the NOTIFY and it sends a Function Management Interface (FMI) Session Status (LU Reactivated) message to the RUI library. The RUI library fails to return an error on the outstanding RUI_WRITE to indicate that the RUI_WRITE will not be responded to. For additional information on SNA Server and Host Integration Server 2000 support for ACTPU(ERP) and ACTLU(ERP) RUs, click the article number below to view the article in the Microsoft Knowledge Base: Q138469 SNA Server Support for ACTPU (ERP) and ACTLU (ERP) Additional query words: ====================================================================== Keywords : kbDSupport sna4 kbsna400sp1 kbsna400sp2 kbsna400sp3 kbhis2000 kbhis2000bug kbsna400sp4 Technology : kbAudDeveloper kbSNAServSearch kbHostIntegServ2000 kbSNAServ400 Version : :4.0 Issue type : kbbug Solution Type : kbnofix ============================================================================= THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY. Copyright Microsoft Corporation 2002.