Is there any way to add one more Data Engine process to have more than one on one box. We recently run into the situation when the process was down and all extracts were erroring out. I was considering adding another one as a way to prevent similar problems in the future. I remember vaguely that it was available in previous versions, but it seems to be just a checkbox in the server configuration for 10.5.1, which is the version we are using now.
I would recommend reading this, The New Data Engine in Tableau Server , and pay particular attention to the section Server configuration and topology. Being that there can only be one per node and that they normally don't go down I would recommend opening up a case with Tableau Support and supply them with your logs should it happen again.