Recovering failed nodes is automatic in the AWS environment. Teradata spins up a replacement node and the instance for the single-node system automatically restarts and is configured on another physical server. The PDE will be in a NODESTART state while the node is recovering. After the system is back up, logons are enabled.
If a node hangs, it does not recover automatically. The instance must be stopped and started again from the AWS Web Console.
There are dozens of reasons for a node failure and it may be difficult for you to determine the cause. If your instance does not automatically restart, first check the alerts in Teradata Server Management or Teradata Viewpoint. You must create the alerts before the node failed. If you cannot resolve the node failure after reviewing the alerts, contact Teradata Customer Support.