You can restart the Dgraph, the HDFS Agent, Studio, and the Dgraph Gateway by running the bdd-admin script with the restart command.
./bdd-admin.sh restart [component] <option>
You can specify any of the component and option arguments listed in About the bdd-admin script.
./bdd-admin.sh restart --all
./bdd-admin.sh restart --agent web009.us.example.com