In a) case, you likely have an un handled exception that restarts the website. Add a try / catch with logging into f.e. C1 log.
Or it could be something like OutOfMemoryExeption that would do the thing.
Can you post code that loads the data into database here? I guess the easiest way would be to optimize the code, so it runs quicker. I guess your site is running on SQL Data Provider, if you aren't inserting records in bulks fixing that should optimize it enough to fit into existing timeout period. The same is true for XML as well
Or it could be something like OutOfMemoryExeption that would do the thing.
Can you post code that loads the data into database here? I guess the easiest way would be to optimize the code, so it runs quicker. I guess your site is running on SQL Data Provider, if you aren't inserting records in bulks fixing that should optimize it enough to fit into existing timeout period. The same is true for XML as well