Correlation Error Causes Unexpected Loss of TN3270(E) Sessions (176574)

SYMPTOMS

Users are logged on to a CICS application via the TN3270(E) server. The CICS application frequently writes data to the user's terminal. At random times, users are suddenly disconnected and have to log on again.

The SNA Server computer's application log shows Event 309:

   WRITE failed with LUA_UNSUCCESSFUL/LUA_RSP_CORRELATION_ERROR

A trace will show the user's session ended with a TERM-SELF and UNBIND.

CAUSE

An unusual sequence of messages results in correlation errors being received from the SNA Server service. The TN3270(E) service treats the correlation errors as fatal errors, resulting in the sessions being disconnected.

STATUS

The TN3270(E) service has been updated so that the correlation error is not handled as a fatal error. This change allows the TN3270 session to be maintained when this error occurs.

Microsoft has confirmed this to be a problem in SNA Server versions 2.11, 2.11 Service Pack 1, 2.11 Service Pack 2, 3.0, 3.0 Service Pack 1, and 3.0 Service Pack 2.

This problem was corrected in the latest SNA Server version 3.0 U.S. Service Pack. For information on obtaining this Service Pack, query on the following word in the Microsoft Knowledge Base (without the spaces):

S E R V P A C K

A supported fix for SNA Server version 2.11 is now available, but has not been fully regression-tested and should be applied only to systems experiencing this specific problem. Unless you are severely impacted by this specific problem, Microsoft recommends that you wait for the next Service Pack that contains this fix. Contact Microsoft Product Support Services for more information.