If I have 2 processes running in different nodes and they share a database, is there a pattern that one node be able to send some notification to the other process via the database?
Is some kind of polling a table normally used or is there a better way?
If you want to use a database, you can insert entries into a table on the producing side and poll to find new entries on the consuming side. This may be the simplest option for your project.
There are many possible alternatives such as JMI, RMI, Sockets, NoSql databases, files, but without more information it's not possible to tell if these would be better. (Often simplest is best)