Multiple-Threaded 3270/LUA Application May Stop Responding (Hang) Opening LU (275565)

SYMPTOMS

The 3270 and/or Logical Unit Application (LUA) applications that use multiple threads to open multiple 3270/LUA logical units (LUs) may enter a state where a thread stops responding (hangs) when it attempts to open one of the 3270/LUA LUs. When this problem occurs, the application may not be to open one (or more) of the requested LUs, which causes the thread requesting the session to hang.

For example, if an application runs on a client that is randomly connecting to several LUs (for example, 20), a thread may hang, while the other threads of the same client may continue to run properly.

Actual results may vary depending upon what the application is doing during this time.

CAUSE

Because of a small timing window in the logon code for SNADMOD, you can lose an "OPEN Message" if an application activates several sessions asynchronously.

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 SNA Server versions 3.0 (all Service Packs), 4.0, 4.0 SP1, 4.0 SP2 and 4.0 SP3..

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