Applicable Versions: All Versions

The error message occurs when the AppServer disconnects unexpectedly without returning any data.

There are two possible causes:-

  1. Default TCP Limit

    This can occur with a long running query that could be hitting the the default TCP limit then disconnecting.

    The default TCP limits can be amended in the Analytics Engine Connection screen (see details below).

    This error is caused by the TCP connection from DataPA to the AppServer timing out. The default settings on a DataPA connection allow the dashboard or query to run for 41 minutes and 40 seconds before returning with the error. 

    This timeout is controlled by two settings which you can set on the Tuning tab of the Connection Details on the System in the Analytics Engine. 

     TCP Client  Retry
     This property sets the number of times that DataPA should check with the AppServer to see if the request is  complete before  giving up and terminating the connection to the AppServer.
     TCP Client Retry  Interval
     The amount of time in hundredths of a second that DataPA should wait between checks with the AppServer  to see if the request  is complete.

    By default the TCP Client Retry is set to 1000 and the TCP Client Retry Interval is set to 250.

    This calculates as 1000 x 250 = 250,000 hundredths of a second = 2,500 seconds = 41 minutes and 40 seconds. 

    If you change the TCP Client Retry to 2000 and the TCP Client Retry Interval to 1000 then that calculates as 2000 x 1000 = 2,00,000 hundredths of a second = 10,000 seconds = 2 hours 46 minutes and 40 seconds and gives the query 8 times longer to complete. 

  2. Network / Firewall Issue

    There is also a possibility that there is a network setting that is causing the timeout.

    If the connection TCP settings are set higher than the default, or the disconnection is occurring prior to the TCP limits and there are no messages on the AppServer to suggest the connection is being closed then it could be that there is a Network / Firewall issue that is stopping the connection.

    The following is a Progress KB that refers.