Logical Unit Application (LUA) session allocation behavior between multiple TN3270 services (326449)


The information in this article applies to:

  • Microsoft Host Integration Server 2004
  • Microsoft Host Integration Server 2000
  • Microsoft SNA Server 4.0
  • Microsoft SNA Server 4.0 SP1
  • Microsoft SNA Server 4.0 SP2
  • Microsoft SNA Server 4.0 SP3
  • Microsoft SNA Server 4.0 SP4
This article was previously published under Q326449

SUMMARY

This article describes the behavior of a Logical Unit Application (LUA) session allocation when a 3270 client that is configured for TN3270 specifies the server name or IP address and pool name when using multiple TN3270 services.

MORE INFORMATION

All 3270 clients that are configured in TN3270 mode and that specify a server name or IP address and LUA pool acquire an LUA logical unit (LU) from the server or IP address that the client specified.

For example:
  • Server A and server B are in the same SNA Subdomain.
  • Available LUA LUs from both servers are assigned to a common LUA pool named LUAPOOL.
  • LUAPOOL is assigned to both TN3270 Services on server A and server B.
  • A 3270 client specifying server A using LUAPOOL will always acquire an LUA LU from server A until all LUA LUs are used up from server A. After that, LUA LUs are pulled from server B.
If the TN3270 service or server A is inactive or unavailable, the 3270 client will not acquire an LUA LU from server B. Instead, you receive an error similar to the following:
Host Connection Timed Out.

REFERENCES

For more information, click the following article numbers to view the articles in the Microsoft Knowledge Base:

185446 TN3270 Server LUA Pool Use Should Load Balance Across Servers

236591 SNA Server LU Allocation Favors Active Remote Connections over Available Local Connections

266275 HIS 2000 Client LU6.2 Load Balancing Across SNA Server Services

268127 TN3270 LUs Must Be Pooled Across Multiple Nodes or Connections

Modification Type:MajorLast Reviewed:5/17/2005
Keywords:kbinfo KB326449
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