DOCUMENT:Q182914  15-MAR-2000  [sna]
TITLE   :SNA Server Can Be "Paused" to Force New Users to Other Servers
PRODUCT :Microsoft SNA Server
PROD/VER:WINDOWS:3.0 SP1,3.0 SP2,3.0 SP3,4.0
OPER/SYS:
KEYWORDS:

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The information in this article applies to:

 - Microsoft SNA Server, versions 3.0 SP1, 3.0 SP2, 3.0 SP3, 4.0 
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SUMMARY
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SNA Server 3.0 Service Pack 1 (SP1) and later versions supports the ability to
"Pause" and "Continue" the SNA Server service (SnaServer). When paused, the SNA
Server continues to support existing client connections, but refuses new client
session requests. This applies to 3270, LUA (including TN3270) and APPC LU
types. Administrators can still administer the SNA Server while it is paused. As
users stop and restart their SNA session access, users connect against alternate
servers that are configured to provide SNA access for the users. This allows an
SNA Server to be brought out of service with minimal user disruption.

Using SNA Server 3.0 (SP1 or later), the SNA Server service can be paused and
continued, using the Windows NT Control Panel "Services" function. The SNA
Server 3.0 Manager interface doesn't support the ability to pause and to resume
the server. However, the SNA Server 4.0 Manager and Microsoft Management Console
interface do support the ability to pause and resume the server directly from
the SNA Server 4.0 management interface.

MORE INFORMATION
================

When the SNA Server service is paused, new user connection requests are refused.
If alternate SNA Servers in the SNA subdomain are configured with SNA session
resources and are available to the user, the user will automatically connect to
the alternate servers. However, if there is a single SNA Server and it is
paused, the following behavior will be observed on the client who attempts to
connect to a paused server:

 - An APPC application's [MC_]ALLOCATE request will fail, with the following
   error:

   primary_rc = 0xF004 (COMM_SUBSYSTEM_NOT_LOADED)
   secondary_rc = 0x010000F0 (or 0xF0000001)

 - A CPIC application's CMALLC request will fail with Error 20
   (CM_PRODUCT_SPECIFIC_ERROR)

 - When opening a 3270 emulation session, the Microsoft SNA Server 3270 program
   displays the following message:

   No SNA Server found in domain.

A 3270 message trace shows that the emulator's Open(SSCP) request fails with an
OPEN SSCP RSP ERROR, with Err1:0000, Err2:0000.

 - When opening a TN3270 session through the SNA Server TN3270 Server, where LUA
   LUs are owned by an SNA Server that has been paused, the SNA Server TN3270
   program displays the following error:

   [TN3270-36] ERROR

 - An error occurred during device type/name processing

Additional query words:

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Keywords          :  
Technology        : kbAudDeveloper kbSNAServSearch kbSNAServ400 kbSNAServ300SP3 kbSNAServ300SP1 kbSNAServ300SP2
Version           : WINDOWS:3.0 SP1,3.0 SP2,3.0 SP3,4.0
Issue type        : kbinfo

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