DOCUMENT:Q178627  22-MAR-1999  [exchange]
TITLE   :XFOR: Chat Server 2.0 Can Fail with Extremely Heavy Usage
PRODUCT :Microsoft Exchange
PROD/VER:WinNT:5.5
OPER/SYS:
KEYWORDS:kbbuglist

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The information in this article applies to:

 - Microsoft Exchange Server, version 5.5 
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SYMPTOMS
========

When an extremely high number of users log on and off the Microsoft Internet
Chat Server version 2.0 in a short period of time, the Chat Server can silently
stop without writing an error to the Event log. The Chat Server can also produce
an application exception in CHATSVC.

CAUSE
=====

This problem was found when a stress test application was written with Visual
Basic and the Chat.ocx. The application logged users on and off without actually
simulating a chat dialog. When run against Internet Chat Server 1.0, the server
generated an error indicating that the NICK was already in use. This means that
the user is connected but not logged on. The Internet Chat Server 2.0 did not
process authentication messages correctly when the NICK was already in use.

STATUS
======

Microsoft has confirmed this to be a problem in Microsoft Exchange Server
version 5.5. This problem has been corrected in the latest U.S. Service Pack for
Microsoft Exchange Server version 5.5. 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

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Keywords          :  kbbuglist
Technology        : kbExchangeSearch kbExchange550 kbZNotKeyword2
Version           : WinNT:5.5
Hardware          : ALPHA PPC x86
Issue type        : kbbug
Solution Type     : kbfix

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