DOCUMENT:Q317642 31-MAY-2002 [sna] TITLE :FIX: APPC/CPI-C Applications May Not Switch to Active Connection PRODUCT :Microsoft SNA Server PROD/VER::4.0 SP4 OPER/SYS: KEYWORDS:sna4 kbsna400sp1 kbsna400sp2 kbsna400sp3 kbhis2000 kbhis2000fix kbsna400sp4 ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft SNA Server, version 4.0 SP4 - Microsoft Host Integration Server 2000 ------------------------------------------------------------------------------- SYMPTOMS ======== An Advanced Program-to-Program Communications/Common Programming Interface for Communications (APPC/CPI-C) application that operates properly with one connection may stop responding (hang) when the application needs to switch to another connection in a Hot Backup or Load Balacing situation. CAUSE ===== SNA Server 4.0 SP4 uses a new load balancing code that does not handle a "lost locality message" properly. RESOLUTION ========== SNA Server 4.0 -------------- 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 SNA Server version 4.0 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: Date Time File name ------------------------------------- 17-Dec-2001 15:35 Wappc32.dll NOTE: Because of file dependencies, the most recent fix that contains the above files may also contain additional files. 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: Date Time File name ------------------------------------- 17-Dec-2001 15:35 Wappc32.dll NOTE: Because of file dependencies, the most recent fix that contains the above files may also contain additional files. STATUS ====== Microsoft has confirmed this to be a problem in Microsoft SNA Server versions 4.0 SP4, and Host Integration Server 2000. MORE INFORMATION ================ Microsoft added a "last good server" field to Host Integration Server 2000 and SNA Server 4.0 SP4 to prevent unnecessary retries to establish a conversation through an active connection. This field is not reset correctly during lost-locality processing, so the resource location code makes repeated attempts to use the non-existent connection. If you enable Systems Network Architecture (SNA) Application internal tracing, the resulting trace may appear as follows: LU62CONN for tpcb 0x1472030 rcb 0x1472128 tpcb_destl is zero - use locality 3 for rcb not first pass open lu62 send non-directed open srci:0x0001 desti:0x0000 send to destl 3 from srcl 0 MangleLPIs in from an App XLPI 0004:00:0002->0004:00:0000 CLP 00:00->03:11 XLPI 0200:00:0002->0003:11:0000 CLP 00:00->03:11 O| XLPI 0200:00:0002->0003:11:0000 CLP 00:00->03:11 O| MHTYP:0x0001 MSGTYP:0x01 OPNQUAL:0x01 OPNTYP:0x24 NUMELT:0x02 L-table entry is not in use, LVAL=1 The last entry: L-table entry is not in use, LVAL=1 indicates the "lost locality message" that the application does not handle properly. Additional query words: Snaservr sp1 sp2 sp3 sp4 1 2 3 4 service pack ====================================================================== Keywords : sna4 kbsna400sp1 kbsna400sp2 kbsna400sp3 kbhis2000 kbhis2000fix kbsna400sp4 Technology : kbAudDeveloper kbSNAServSearch kbHostIntegServ2000 kbSNAServ400SP4 Version : :4.0 SP4 Issue type : kbbug Solution Type : kbfix ============================================================================= 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. 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