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Connector full import synchronization aborts encompassing transaction against large number of deletes (> 500,000 entities)

Tony Sheehy 13 years ago • updated by anonymous 8 years ago • 4

A connector full import/sync that results in a large number of deletions (> 500,000) will abort its respective encompassing TransactionScope.

The following was additionally observed when the TransactionScope was observed to abort:

  • When debugging, the TransactionScope itself is registered as complete. (TransactionScope::complete = true)
    • From this, it can be potentially inferred that the problem itself happens either on the MSDTC or SQL Server end - as far as the IdB application is concerned, the TransactionScope completed.
  • The exception was thrown during IDB ChangeDetection.
  • If debugging, ensure that break on all exceptions is enabled.
  • During the import, in the respective SQL traces, a substantial number of entries were logged with the following EventClass and ApplicationName. 
    EventClass: Lock:Timeout
ApplicationName: .Net SqlClient Data Provider
Tony Sheehy 13 years ago

The TransactionScope was timing out because all deletions would be pulled in at once (~500,000 entities in test import). This was compounded by the fact that although the TransactionScope timeout was equal to ~2.7 hours, the Maximum available Transaction timeout defaults to 10minutes and is only configurable in the respective host machine.config. This configuration needs to be set in the following way:

<system.transactions>
	<machineSettings maxTimeout="<MAX_TIMEOUT: e.g. 2:00:00>"/>
	<defaultSettings timeout="<DEFAULT_TIMEOUT: e.g. 00:03:00>"/>
</system.transactions>

Additionally the following can be set to enable editing from the application side:

<sectionGroup name="system.transactions" type="System.Transactions.Configuration.TransactionsSectionGroup, System.Transactions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089, Custom=null">
	<section name="defaultSettings" type="System.Transactions.Configuration.DefaultSettingsSection, System.Transactions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089, Custom=null"/>
	<section name="machineSettings" type="System.Transactions.Configuration.MachineSettingsSection, System.Transactions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089, Custom=null" allowDefinition="MachineOnly" allowExeDefinition="MachineOnly"/>
</sectionGroup>

This however is only a workaround, and the entire Full import paging mechanism will need to be replaced such that entities are paged/deleted in separate transactions.

Tony Sheehy 13 years ago

Reassigned for confirmation of completeness.

Adam van Vliet 13 years ago

Closed.

Matthew Clark 12 years ago

Covered by 6.0 Performance in the regression test document

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