Server Displays Offline When Link Drops and Recovers

• Microsoft SNA Server, version 3.0

SYMPTOMS

If the network connection between SNA Server Manager and a remote SNA Server service is lost, the SNA Server service shows a status of "Offline." If the network connection is reestablished within a few minutes, it stays offline until the administrator reopens the SNA subdomain in the SNA Server Manager.

CAUSE

If the network connection between the Manage Client to the Manage Agent fails, the SnaBase service (which relies upon broadcasts) still considers the services to be active. If the connection is reconnected before the SnaBase service frees the services from the services table, the SnaBase service never sends a service table update to indicate the services have recovered. Therefore, the network connection is never reestablished. This may cause the SNA Server Manager to display the SNA Server status as "Offline."

RESOLUTION

An update to SNA Server 3.0 is available to correct this problem. With the new Manage files, Mngcli.exe will now retry a dropped connection to Mngagent.exe three times with a two-minute delay between each retry. If the outage is longer than four minutes (the default setting), SnaBase detects the recovery and signals Mngagent.exe to try again. If the server broadcast times are changed to be longer, these times may need to be adjusted. The value of the retry delay multiplied by the number of retries should be slightly longer than the server broadcast value multiplied by four. The server broadcast value, which has a default of 60 seconds, is configured in the Server Broadcasts folder in the SNA Server Manager, in the SNA Server properties. The registry entries for adjusting these settings are:

   HKEY_Local_Machine\Software\Microsoft\SNA Server\Parameters\Manage\
      ConnectRetryLimit: REG_DWORD: <value>

   HKEY_Local_Machine\Software\Microsoft\SNA Server\Parameters\Manage\
      ConnectRetryDelay: REG_DWORD: <value>

   <Snaroot>\System\Mngagent.exe
   <Snaroot>\System\Mngcli.exe
   <Snaroot>\System\Snamanag.dll

STATUS

Microsoft has confirmed this to be a problem in SNA Server version 3.0. This problem was corrected in the latest Microsoft SNA Server 3.0 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