Hi , Adam.
Since a new server was added to the cluster ensure it has all drivers installed correctly. Only the Oracle driver is default ins a tableau installation.
We recently distributed our server, adding a new worker, and are seeing the same thing. Any subscription that takes more than ~20 seconds to complete fails. If we remove the worker this issue goes away. However there are no problems refreshing the view from the server or updating the data sources on the worker server. Only subscriptions with times greater than 20 sec are impacted. We are using 10.1. Anyone have an idea how to fix this? Is it a known issue with this version? Will an update fix the problem?