Don't worry! It's only stuff...

https://glassfish.java.net/download.html
http://download.oracle.com/glassfish/4.1/promoted/index.html

# parameter
grep pass /etc/init.d/glassfish
ASADMINOPTS="--user admin --passwordfile /opt/glassfish/pass"

# asadmin
http://docs.oracle.com/cd/E19798-01/821-1758/6nmnj7pso/index.html
/opt/glassfish/bin/asadmin --user admin --passwordfile /opt/glassfish/conf/pass list-jvm-options | grep Dcom.sun.management.jmxremote.port
/opt/glassfish/bin/asadmin --user admin --passwordfile /opt/glassfish/conf/pass create-jvm-options -Dcom.sun.management.jmxremote.port=1234
/opt/glassfish/bin/asadmin --user admin --passwordfile /opt/glassfish/conf/pass delete-jvm-options -Dcom.sun.management.jmxremote.port=1234
/opt/glassfish/bin/asadmin --user admin --passwordfile /opt/glassfish/conf/pass list-applications

asadmin list-applications
asadmin list-applications customer-service-instance

# show system properties
list-system-properties

get
/opt/glassfish/bin/asadmin --user admin --passwordfile /opt/glassfish/conf/pass get secure-admin.enabled

# remote
ssh foo@glassfish.example.com -t "bash -ic 'asadmin list-instances'"

# logs
tail -f /opt/glassfish/domains/domain1/logs/*.log

Alternatives
http://www.payara.fish/