Microsoft KB Archive/281516

= APPC/CPI-C Applications Cannot Get APPC Sessions =

Article ID: 281516

Article Last Modified on 2/20/2007

-

APPLIES TO


 * Microsoft Host Integration Server 2000 Standard Edition
 * Microsoft SNA Server 4.0
 * Microsoft SNA Server 3.0 Service Pack 2
 * Microsoft SNA Server 3.0 Service Pack 3
 * Microsoft SNA Server 3.0 Service Pack 4
 * Microsoft SNA Server 4.0
 * Microsoft SNA Server 4.0 Service Pack 1
 * Microsoft SNA Server 4.0 Service Pack 2
 * Microsoft SNA Server 4.0 Service Pack 3
 * Microsoft SNA Server 4.0 Service Pack 4

-



This article was previously published under Q281516



SYMPTOMS
SNA Server and Host Integration Server (HIS) 2000 may stop allocating new LU 6.2 (APPC) sessions after some period of continuous uptime. Currently active LU 6.2 sessions are unaffected and continue to function properly.

If you are running an APPC or CPI-C application, you may see various symptoms depending on the design of the application you are using. Because most APPC and CPI-C applications are designed to wait for an available LU 6.2 session, the most common symptom is that the application stops responding (hangs) while it waits for a session.

If the application is designed to time out if an LU 6.2 session is not available, the underlying [MC_]ALLOCATE fails. In this case, the [MC_]ALLOCATE may fail with the following error message:

primary_rc = 0x0003 (AP_ALLOCATION_ERROR)

secondary_rc = 0x00000005 (AP_ALLOCATION_FAILURE_RETRY)

A CPI-C application that times out may return the following error message:

rc = 20 (CM_PRODUCT_SPECIFIC_ERROR)

In addition, the SNA Server may log the following event message repeatedly in the Application Event Log when it stops allocating LU 6.2 sessions:

Event ID: 11

Source: SNA Server

Description: (1178) Initialization Failure

EXPLANATION

This is an internal logic error in SNA Server, related to the configuration.

SUBCODE INFORMATION

X'1177' Operator queues are full--messages have been lost.

X'1178' Insufficient resources for automatic session limit negotiation.



CAUSE
SNA Server is not releasing an internal control block that is used for Change Number of Sessions (CNOS) processing once CNOS is completed under very specific circumstances. SNA Server supports a fixed number of these special control blocks, and therefore, over time this type of control block &quot;leak&quot; leads to a situation where there are no available control blocks. Once the control blocks are exhausted, SNA Server cannot initiate CNOS processing over any APPC triplets (Local APPC LU/Remote APPC LU/Mode) that require CNOS. In addition, the SNA Server starts logging Event 11 messages, as described earlier.



SNA Server 4.0
A supported fix is now available from Microsoft, but it is only intended to correct the problem that is described in this article. Apply it only to computers that are experiencing this specific problem. This fix may receive additional testing. 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 hotfix.

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, visit the following Microsoft Web site:

http://support.microsoft.com/default.aspx?scid=fh;EN-US;CNTACTMS

NOTE: In special cases, charges that are ordinarily incurred for support calls may be canceled if a Microsoft Support Professional determines that a specific update will resolve your problem. The typical 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:

NOTE: Because of file dependencies, the most recent fix that contains the preceding files may also contain additional files.

Host Integration Server 2000
To resolve this problem, obtain the latest service pack for Host Integration Server 2000. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

328152 How to Obtain the Latest Host Integration Server 2000 Service Pack

The English version of this fix should have the following file attributes or later:

NOTE: Because of file dependencies, the most recent fix that contains the preceding files may also contain additional files.



STATUS
Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article. This problem was first corrected in Host Integration Server 2000 Service Pack 1.

Additional query words: Snaservr sp1 sp2 sp3 sp4 1 2 3 4 service pack

Additional query words: HIS 2000

Keywords: kbbug kbfix kbhostintegserv2000sp1fix kbhostintegserv2000presp1fix KB281516

-

[mailto:TECHNET@MICROSOFT.COM Send feedback to Microsoft]

© Microsoft Corporation. All rights reserved.