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.netvb.netsql-server-2005linq-to-sqlmsdtc

How to determine why a distributed transaction is timing out

I am using LINQ to SQL and a third party SDK that supports distributed transactions. When I realize that a pending update will be updating both SQL records and records in the third party SDK, I am creating a TransactionScope with a 0 (presumably infinite) timeout (although I've also tried 12 hours as a timespan parameter). Then I use GetDtcTransaction on the ambient transaction (created by transactionscope) to get a DTC transaction to link to the third party SDK. Things work nicely for about 10 minutes, but after 10 minutes, the transaction disappears and an error occurs. How do I determine why the transaction is disappearing. I suspect it's a timeout because it regularly occurs after 10 minutes even though slightly varying degrees of work have been done at that point. But I'm at a loss about how to determine what terminated the transaction, why, and how to extend its life.

I've tried tracingthe following events with SQL profiler:

  1. All error and warning events
  2. All Security events except "Audit Schema Object" events
  3. All Transaction events except SQLTransaction and TransactionLog events

All I get around the time of the error are these events:

<Event id="19" name="DTCTransaction">
  <Column id="3" name="DatabaseID">1</Column>
  <Column id="11" name="LoginName">sa</Column>
  <Column id="35" name="DatabaseName">master</Column>
  <Column id="51" name="EventSequence">167065</Column>
  <Column id="12" name="SPID">10</Column>
  <Column id="60" name="IsSystem">1</Column>
  <Column id="1" name="TextData">{D662BBC4-21EC-436D-991C-DCB061A34782}</Column>
  <Column id="21" name="EventSubClass">16</Column>
  <Column id="25" name="IntegerData">0</Column>
  <Column id="41" name="LoginSid">01</Column>
  <Column id="49" name="RequestID">0</Column>
  <Column id="2" name="BinaryData">C4BB62D6EC216D43991CDCB061A34782</Column>
  <Column id="14" name="StartTime">2009-11-11T13:55:32.82-06:00</Column>
  <Column id="26" name="ServerName">.</Column>
  <Column id="50" name="XactSequence">0</Column>
</Event>
<Event id="33" name="Exception">
  <Column id="3" name="DatabaseID">9</Column>
  <Column id="11" name="LoginName">sa</Column>
  <Column id="31" name="Error">1222</Column>
  <Column id="35" name="DatabaseName">ACS</Column>
  <Column id="51" name="EventSequence">167066</Column>
  <Column id="12" name="SPID">19</Column>
  <Column id="20" name="Severity">16</Column>
  <Column id="60" name="IsSystem">1</Column>
  <Column id="1" name="TextData">Error: 1222, Severity: 16, State: 18</Column>
  <Column id="41" name="LoginSid">01</Column>
  <Column id="49" name="RequestID">0</Column>
  <Column id="14" name="StartTime">2009-11-11T13:55:34.717-06:00</Column>
  <Column id="26" name="ServerName">.</Column>
  <Column id="30" name="State">18</Column>
  <Column id="50" name="XactSequence">0</Column>
</Event>
<Event id="33" name="Exception">
  <Column id="31" name="Error">8525</Column>
  <Column id="8" name="HostName">MARTY755</Column>
  <Column id="12" name="SPID">55</Column>
  <Column id="20" name="Severity">16</Column>
  <Column id="64" name="SessionLoginName">fse</Column>
  <Column id="1" name="TextData">Error: 8525, Severity: 16, State: 1</Column>
  <Column id="9" name="ClientProcessID">2516</Column>
  <Column id="41" name="LoginSid">DB2744F54B5CDB4A8B9E5CA9C209A7AC</Column>
  <Column id="49" name="RequestID">0</Column>
  <Column id="10" name="ApplicationName">.Net SqlClient Data Provider</Column>
  <Column id="14" name="StartTime">2009-11-11T13:55:37.54-06:00</Column>
  <Column id="26" name="ServerName">.</Column>
  <Column id="30" name="State">1</Column>
  <Column id="50" name="XactSequence">236223201284</Column>
  <Column id="3" name="DatabaseID">9</Column>
  <Column id="11" name="LoginName">fse</Column>
  <Column id="35" name="DatabaseName">ACS</Column>
  <Column id="51" name="EventSequence">167067</Column>
</Event>
<Event id="162" name="User Error Message">
  <Column id="31" name="Error">8525</Column>
  <Column id="8" name="HostName">MARTY755</Column>
  <Column id="12" name="SPID">55</Column>
  <Column id="20" name="Severity">16</Column>
  <Column id="64" name="SessionLoginName">fse</Column>
  <Column id="1" name="TextData">Distributed transaction completed. Either enlist this session in a new transaction or the NULL transaction.</Column>
  <Column id="9" name="ClientProcessID">2516</Column>
  <Column id="41" name="LoginSid">DB2744F54B5CDB4A8B9E5CA9C209A7AC</Column>
  <Column id="49" name="RequestID">0</Column>
  <Column id="10" name="ApplicationName">.Net SqlClient Data Provider</Column>
  <Column id="14" name="StartTime">2009-11-11T13:55:37.54-06:00</Column>
  <Column id="26" name="ServerName">.</Column>
  <Column id="30" name="State">1</Column>
  <Column id="50" name="XactSequence">236223201284</Column>
  <Column id="3" name="DatabaseID">9</Column>
  <Column id="11" name="LoginName">fse</Column>
  <Column id="35" name="DatabaseName">ACS</Column>
  <Column id="51" name="EventSequence">167068</Column>
</Event>

EventSubClass 16 on the DTCTransaction event indicates "Transaction is aborting".

Solution

  • To extend the timeout, which defaults to 10 minutes maximum when not specified, it's necessary to update C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\CONFIG\Machine.config on the target system (look under C:\Windows\Microsoft.NET\Framework64\v2.0.50727\CONFIG if you're running 64-bit). Add this as the last item right under the root level:

    <system.transactions>
    <machineSettings maxTimeout="23:00:00"/>
</system.transactions>

    This will (as an example) set the timeout to 23 hours.

    The effective value is visible in System.Transactions.TransactionManager.MaximumTimeout