Article ID: 137901
Article Last Modified on 11/19/2003
APPLIES TO
- Microsoft SNA Server 2.1, when used with:
- Microsoft SNA Server 3.0, when used with:
This article was previously published under Q137901
SYMPTOMS
The following symptoms can occur when 15 or more SNA Servers are installed
within a single Windows NT domain and Windows 3.x clients are being used:
- The 3270 applet may fail to start and report "DL-BASE not initialized."
- If you are using Wall Data Rumba, Rumba 3270 may fail to start and
display the Interface Not Found message.
- Clients that open an SNA application session may experience long
delays before receiving a host sign-on screen.
- The Windows NT application event log will include:
Event ID: 564
Description: Failed to initialize exit list processing, rc = 563
Event ID: 563
Description: The service table is full: too many network resources
active.
NOTE: The SNA client reports Event 563 to the server, so it's the
client's internal "service table" that is full, not the server's.
CAUSE
The SNA Server Windows 3.x client software supports sessions through
multiple SNA Servers. However, if there are more than 14 SNA Servers
currently running in the SNA Server domain, Win 3.x clients begin
experiencing these problem due to an internal limit within the SNA Server
Windows 3.x client service table. The service table is used by the
SNA Server client to internally manage the SNA client resources
being used on the client machine.
The SNA Server Win 3.x client service table contains 32 entries:
- Two "overhead" entries (one for the sponsor connection [sponap]
and one entry for WNAP).
- One entry for every SNA Server service currently running in the domain.
- One entry for every SNA Server configuration server (snabase)
running in the domain (i.e. primary and backup servers).
- One for each active Windows process which uses the SNA Win 3.x
client API interfaces (i.e. the 3270 and 5250 applets each take
one entry).
- One for every "otherservers" entry configured on the client machine.
- One for every invokable TP registered on the client machine.
If "otherserver" and APPC TPs are not being used, and you want to run a
3270 emulation product on the client, the maximum number of SNA Server
config servers in the domain is (32 - 3 = 29 % 2) = 14. If more than 14 SNA
servers are running in the domain, the above errors will be logged and the
user will not be able to run an emulator on the SNA Server Win 3.x client
machine.
RESOLUTION
Microsoft has updated the following files to correct this problem:
<snaroot>\WNAP.EXE
WINDOWS\SYSTEM\WDMOD.DLL
NOTE: These files are applied to the SNA Server Windows 3.x client, not the
SNA Server.
The update to the SNA Win 3.x client software limits the number of
configuration servers kept in the service table to 2 entries. This extends
the theoretical number of SNA Servers supported in a domain to 27. However,
Microsoft strongly recommends that SNA Server 2.11 be deployed and the
subdomain feature implemented, allowing SNA Servers to be separated into
logical groups within a Windows NT domain. Using the subdomain feature, the
client users would connect only through one group of servers at a time. See
the SNA Server 2.11 Readme file for more information about the subdomain
feature.
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):
Additional query words: 2.00 2.10 2.11 prodsna session drop hang
Keywords: kbbug kbfix KB137901