I have 2 MERGE statements involving 4 tables each with 30 million + rows. I am running these 2 statements in parallel using SSIS's execute SQL task and they were running successfully in 2 hrs. till last week. All of sudden these queries going into suspended mode and now taking almost 24 hrs. I haven't made any changes to my SQL Server installation (SQL Server 2012 NT x64) or SSIS package. I have implemented custom logging in the package where i log the OnPreExecute and OnPostExecute events. When i check the time lag between these two events of the MERGE statements strangely it is still 2-2.30 hrs.
What would be the root cause of this problem?