I am running a SQL Server 2008 R2 SP2 DB. I have a DB that was running around 19 GB in size and three days ago grew to 34 for no good reason. We typically have about 100 MB growth in the DB every month or so, so this jump up by 15 GB is unexpected. At the same time I started seeing SQL Server eating up more and more RAM from the server. It's typical to see it run at around the 6-8 GB range but all of sudden its taking up to 24 GB of the 32 GB the server has. Again unexplained. I have rebuilt all the indexes, did a FILE shrink (not a DB and never a DB), did a full backup and nothing helped. I was forced to set MaxMemory limit at 16 GB to stabilize things but I have no clue what else I can do. The only change that was ever made over the last week was that a login name that was part of a Domain Controller (Admin account) was removed from SQL Server and replaced with a local Admin account.
I don't have performance states to share at the moment but wondering what could cause the sudden bloat in the DB and what can I look into or do about it? This DB has been running for 4 years without one single issue except for now. I am not a DBA so any help would be appreciated.