Microsoft KB Archive/275708

= TN3270E Bracket Error Because of Race Condition =

Article ID: 275708

Article Last Modified on 12/29/2003

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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 Q275708



SYMPTOMS
TN3270(E) clients may intermittently lose their session to the host application. When the failure occurs, the emulator may display a message indicating that a &quot;BRACKET ERROR&quot; was encountered; the actual format of the message varies depending on the TN3270(E) emulator that is being used.

SNA application LUA API traces that are gathered during the failure indicate the following return codes on the failed session:

prim_rc=0x1400 (LUA_UNSUCCESSFUL) sec_rc=0x00000320 (LUA_BRACKET)

In addition, the Microsoft Windows NT application event log shows the following events at the time the failure occurred:

EventID : 603

Source : TN3270 Server

Description : TN3270(E) session with client at xxxx.xxxx.xxxx.xxxx (port xxxx) using LU ABCD terminated abnormally because:

TN3270E Service Error 505

SNA API verb WRITE failed. Failure described as:

RUI Write verb has completed with primary rc of Unsuccessful and secondary rc of Bracket Protocol Error.

Explanation : A TN3270(E) client session was terminated abnormally

EventID : 309

Source : TN3270 Server

Description : WRITE failed with LUA_UNSUCESSFUL / LUA_BRACKET for xxxx.xxxx.xxxx.xxxx(port xxxx)

Explanation : An SNA API call failed



CAUSE
The TN3270 server received direction on the session on an RQD chain, and should have discarded any queued data from the client. Instead, the server attempted to send the queued data to the host, and subsequently received the bracket error.



RESOLUTION
To resolve this problem, obtain the latest service pack for SNA Server 4.0. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

215838 How to Obtain the Latest SNA Server Version 4.0 Service Pack



STATUS
Microsoft has confirmed that this is a problem in Microsoft SNA Server version 4.0.

This problem was first corrected in SNA Server 4.0 Service Pack 4.

Keywords: kbbug kbfix kbsna400presp4fix kbqfe kbsna400sp4fix KB275708

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