Memory Leak in TN3270 Server if RU Sizes Exceed TN3270 Defaults

• Microsoft SNA Server, version 2.11
  on the following platforms: NT

SYMPTOMS

When the TN3270 server runs for many days or weeks, server performance becomes sluggish and Windows NT eventually runs out of virtual memory. Also, Windows NT performance monitor shows paged pool bytes to be steadily increasing for the TN3SERVR process.

CAUSE

The TN3270 server initially allocates inbound and outbound buffers when a TN3270 client connects to the server, using the inbound and outbound "Default RU sizes" configured in the TN3270 Admin Options dialog.

However, if the TN3270 client's BIND request negotiates to larger RU sizes than these defaults, the TN3270 server allocates new inbound and outbound buffers though never frees the previously acquired buffers.

RESOLUTION

To workaround this problem, increase the Inbound and/or Outbound default RU sizes within the TN3270 Server Admin Options dialog to accommodate the largest RU sizes that will be requested by the TN3270 client users.

To correct this problem, install the update to the SNA Server 2.11 TN3270 service mentioned below. Microsoft has updated the file <ntroot>\TN3SERVR.EXE to correct this problem.

STATUS

Microsoft has confirmed this to be a problem in SNA Server for Windows NT. This problem was corrected in the latest SNA Server for Windows NT, 2.11 U.S. Service Pack. For information on obtaining the Service Pack, query on the following word in the Microsoft Knowledge Base (without the spaces):

S E R V P A C K

Additional query words: prodsna 3.50 3.51

Keywords : ntnetserv
Version : WINDOWS:2.11
Platform : WINDOWS
Issue type :