In your previous forum question, you are having the following attributes enabled
connection-leak-reclaim="true" connection-leak-timeout-in-seconds="180"
http://forums.java.net/jive/thread.jspa?messageID=484460
This (leak-reclaim=true) means if the connection is not returned within 180 seconds it will be reclaimed by the pool. Pool will destroy the connection (close) as it may be in unusable state there by giving room for filling the pool with a valid new connection so that it can be made available to applications.
Since you already know that the application will take more than 180 seconds, connection-leak-timeout-in-seconds must be much more than 180 seconds so that the connection is not reclaimed by the pool even before the typical time for which the application might hold the connection for use.
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