Originally I had run one discourse forum on the 8GB ram, 4core CPUs server.
So the values of db_shared_buffers and UNICORN_WORKERS in the auto-generated app.yml were:
db_shared_buffers: "1792MB"
UNICORN_WORKERS: 8
Now I have three discourse forums running on the same 8GB ram, 4core CPUs server.
Should I change the value of db_shared_buffers and UNICORN_WORKERS to divided by three?