DOCUMENT:Q182009  02-APR-1999  [exchange]
TITLE   :XCON: MTA Queue Slow, with Errors 2127, 2155, 2202, 2194
PRODUCT :Microsoft Exchange
PROD/VER:5.0
OPER/SYS:
KEYWORDS:kbusage

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The information in this article applies to:

 - Microsoft Exchange Server, version 5.0 
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SYMPTOMS
========

After deleting a message from an Exchange Server Message Transfer Agent (MTA)
queue, you may see a build-up of messages for that particular queue, and the
following errors in the Application Event log:

   Event 2127   MSExchangeMTA
   An MTA database server error was encountered. Error accessing object
   attribute (AAT) on a Read/Write operation. Filename:
   e:\exchsrvr\mtadata\.\DB000068.DAT. File operation: 0. Operating system
   error: 2127. Referenced object: OPEN (00000000 => N/A). Referenced
   object error 00000000. [0 DB Server OPERATOR 22] (14)

   Event 2155   MSExchangeMTA
   An MTA database server error was encountered. Failed to read attribute
   information (AAT) for object 01000068. Database server error code: 2127.
   [DB Server OPERATOR 22 29] (14)

   Event 2202   MSExchangeMTA
   A fatal MTA database server error was encountered. The object
   reservation count for object 01000000 has been decremented below zero.
   [DB Server OPERATOR 22 14] (16)

   Event 2194   MSExchangeMTA
   An MTA database server error was encountered while getting the next
   entry from a queue. Called from MTA. Procedure 162. Database error code:
   ODXAATRW - I/O Error on AAT file (read/write). Queue: 01000068. [DB
   Server OPERATOR 22 66] (14)

CAUSE
=====

The Exchange Administrator program was being used to delete a message from the
Microsoft Mail Interchange queue at the same time that the Exchange MTA was
attempting to record the message in the Message Tracking log.

For example, while the MTA was processing messages, someone used the Exchange
Administrator program to delete a message in a queue. The message was deleted at
the same time the MTA was trying to record it in the Message Tracking log. (This
is a very narrow time window and should occur very rarely.) Message flow slowed
down, because an MTA thread was tied up trying to do something to a message that
another MTA thread had deleted, hence the build-up of messages in the queues.

STATUS
======

Microsoft has confirmed this to be a problem in Exchange Server version 5.0.


A supported fix is now available, but has not been fully regression-tested and
should be applied only to systems experiencing this specific problem. Unless you
are severely impacted by this specific problem, Microsoft recommends that you
wait for the next Service Pack that contains this fix. Contact Microsoft
Technical Support for more information.

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Keywords          : kbusage 
Technology        : kbExchangeSearch kbExchange500 kbZNotKeyword2
Version           : 5.0
Hardware          : ALPHA x86
Issue type        : kbbug
Solution Type     : kbfix

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