In reference start-stop-daemon to create multiple instances of executable through upstart, the author Atul Dambalkar mentioned a way to start multiple instances via start-stop-daemon, which is by specify the --name option.

start-stop-daemon --start --quiet --chuid myuser --name myapp1 \
                  --exec /usr/bin/myapp -- --config /etc/myapp-configfile1

start-stop-daemon --start --quiet --chuid myuser --name myapp2 \
                  --exec /usr/bin/myapp -- --config /etc/someapp-configfile2

However, it cannot execute correctly in upstart, because start-stop-daemon will block at the first command and the second one will not be executed. Specify the –background(-b) option will not correct this because it will fork the instance and you can no longer use stop command to manage the forked instance since its pid is changed.

The fix is simple, just let the start-stop-daemon run in background by append the &, and be careful, the last command of start-stop-daemon should not end with &, if every command are run in background, the stop command will fail and you can only terminate the instances via kill command. The final solution is:

start-stop-daemon --start --quiet --chuid myuser --name myapp1 \
                  --exec /usr/bin/myapp -- --config /etc/myapp-configfile1 &

start-stop-daemon --start --quiet --chuid myuser --name myapp2 \
                  --exec /usr/bin/myapp -- --config /etc/someapp-configfile2

Reference

• http://upstart.ubuntu.com/cookbook
• start-stop-daemon to create multiple instances of executable through upstart

License: (CC 3.0) BY-NC-SA