Microsoft KB Archive/262027

= Enabling SyncPoint May Cause SNA Server Event 60, 730 =

Article ID: 262027

Article Last Modified on 10/22/2003

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APPLIES TO


 * 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

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This article was previously published under Q262027



SYMPTOMS
The following events are logged in the Windows NT Application Event Log on the SNA Server: Event ID: 60 Source: SNA Server Description: Failed to invoke APPC TP 06F2, local LU = , Sense Data = 84c0000

Event ID: 730 Source: SNA Server Description: The SNA Server was unable to locate an invokable TP UN2, APPC LU Alias , Workstation name: . NOTE: If Event 60 is occurring for an advanced program-to-program communications (APPC) transaction program (TP) name other than 06F2 (UN2), then this article does not apply to the problem.



CAUSE
If an SNA Server local APPC Logical Unit (LU) SyncPoint Support checkbox is selected, SNA Server indicates support for SyncPoint in its BIND request when it establishes an LU6.2 session with the host subsystem. The subsystem (such as the Customer Information Control System [CICS]) may detect this support and initiate an attach request to start a conversation with the SNA Server Resynchronization transaction program (TP) in order to perform an Exchange Log Names request, which is required for SyncPoint-enabled LUs. However, if the COM Transaction Integrator (COMTI) has not been installed with SNA Server, this TP will not exist and the host request will be rejected.



RESOLUTION
Install COMTI to provide SyncPoint support, or if SyncPoint support has been enabled in error, then disable SyncPoint support on the local APPC LUs.

To disable SyncPoint support, open Properties for the local LU specified in the events, and go to the Advanced tab. Under SyncPoint Support, clear Enable, save the configuration, and then stop and restart the SNA Server Service.



MORE INFORMATION
The SyncPoint function allows all TPs that are processing a distributed transaction to coordinate error recovery and maintain consistency among distributed resources, such as databases.

The SyncPoint function affects protected resources. These include conversation resources and implementation or installation-designated resources, such as databases. Any changes to a protected resource are logged so that they can be either backed out (reversed) if the transaction detects an error, or committed (made permanent) if the transaction is successful.

In order for a protected conversation to be allocated, both LUs must support the IBM Sync Level 2 protocol. The two LUs exchange their synchronization support levels in byte 24 of the BIND. The negotiation of support is handled by the Exchange Log Name (X'1211') General Data Stream (GDS) variable. The resync service implements the &quot;Exchange Log Names&quot; function of an SNA transaction manager.

COMTI provides a resynchronization service (SNA LU 6.2 Resync TP). This Windows NT service is configured to be the auto-started invokable service for the SNA-defined Resync TP (0x06F2).

All of COMTI's resync and 2PC flows are implemented in conformance with the SNA Sync Point Services Architecture Reference (IBM SC31-8134-00).

