For the sake of transparency, I want to update you all on what was causing the intermittent issues, why we brought the servers down and why it took a few hours to bring them back up.
This morning, we noticed that a number of players were having intermittent issues with draft as well as pack opening so we started investigating what was the cause of these issues. we then found out that a small query that one of our engineers ran against the database got stuck and were putting locks on a number of database tables, hence causing certain functions such as drafting a new deck or opening a new pack to slow down or fail.
Anyways, we decided to bring the servers down so that we could fix the database issue but before we could do that, we wanted to put a recovery plan in place (ie. database restore) should the database fixing fail and that's what took a few hours.
Fortunately, we were able to successfully fix the database issue so we didn't need to act on the recovery plan but given that this was an unscheduled emergency update, we felt that it was good practice to have it in place just in case.
Thanks again to everyone in the community for your patience and see you back on the battlefield!