An application needs to extract large volumes of data from cubes.



Things are organized so that after the client connects to the server it
partitions the data requests between a number of worker threads. The worker
threads all shared the same ADODB connection object (using the OLE-DB for
olap client) which is passed into the worker thread on creation as part of
another object that contains an MDX query for that request and various other
bits and bobs to manage the synchronisation of the worker threads.



As the live cube was not available during development this approach was
prototyped on FoodMart and seemed to work well giving good data throughput.



The real cube is now available for testing and a problem has arisen. The
server seems to intermittently and unilaterally drop the connection. The
profiler had been configured to report query events, security events and
session events. A sequence of Query Begin and Query End events are
observer as the worker threads are dispatched from the client followed by an
Audit Logout event. If the data extract is successful the Audit Logout does
not occur until all the queries have been processed.



Fairly frequently with the live cube an Audit Logout occurs before the
client code has logged out and before all the queries have been submitted.
On the client side all of the queries that are submitted after this event
fail (not surprisingly as the client is no longer logged on).



What has initiated this logout event and why?



If anyone can give me some pointers as to how to most effectively
investigate/diagnose this problem I would be very pleased to hear from you.



TIA



Andy