TdConnection.Open is now more reliable and persistent in establishing connections to the Advanced SQL Engine. TdConnection.Open has been enhanced to attempt to recover from transient network faults. TdConnection.Open will retry those transient network faults until the TdConnection.ConnectionTimeout has expired or the ConnectMaxRetryCount has been reached. However Redrive and Recoverable Network Protocol (RNP) are not enabled during TdConnection.Open. These features are used only once the connection is established and opened.
Each connection retrieved from a connection pool will be tested first before being returned to an application requesting a pooled connection. A test message with a predetermined timeout will be sent and verified by the Data Provider. The Data Provider will close the connection that failed the test message verification, and continue to retrieve connections from the pool, until either a connection has been verified or the connection pool has been depleted.