My experience with AWS hasn't been good when we had major problems in redshift becoming unresponsive. Since it was an intermitent issue and not a full blown blackout they just shrugged and we kept having problems for months.
I can confirm. Redshift support is mediocre even for a F100 firm with TAM support if the workload is large and complex and you have some needle in the haystack causing problems like you allude to.
Practically speaking keeping an eye on locks and transactions is a good idea, as is watching out for your statistics on key core columns going bad when they shouldn't. (analyze and vacuum sometimes don't actually do anything when you need them to...)
Practically speaking keeping an eye on locks and transactions is a good idea, as is watching out for your statistics on key core columns going bad when they shouldn't. (analyze and vacuum sometimes don't actually do anything when you need them to...)