Before the data import for finished, its data source timed out. Double-check whether that data sour

kumar27 

Try restarting the machine that has the gateway installed on.
Yesterday our datasets went out and this morning, after restarting machine with gateway and turning scheduled refresh back on it seems to be working again.
Both on demand refreshes and scheduled ones have cleared for us so far.

We are running gateway in personal mode.
Although the gateway reads an "OK" on dataset settings page there seems to be some issue with it.
Over the last few weeks about 5 of our largest data sets started to become inconsistent with scheduled refreshes and eventually went down completely.

At first it impacted just some of the scheduled updates and error message was:
"Failure details: The last refresh attempt failed because of an internal service error. This is usually a transient issue. If you try again later and still see this message, contact support."

Eventually the scheduled refresh stopped completely for all datasets and error message switched out to:
"Before the data import for finished, its data source timed out. Double-check whether that data source can process import queries" which in turn also disabled the scheduled refreshing in general.

Only thing I can think of that might have caused this, might be general growth of one of our datasets.
Maybe it has gotten so large that it requires a lot of time to process and somehow causes other updates using the same gateway and accessing the same server to get bunched up somehow.
Admittedly we are running a rather old installation of gateway and might update in future if problem persists, but it had no issues like this for years so we havent bothered to update it.