Advanced installations are not officially supported but here we are at least documenting some tips and tricks that you might find helpful. You can find a diagram of an advanced installation in the Preparation section.
The main thing to know about running multiple Glassfish servers is that only one can be the dedicated timer server, as explained in the Dataverse Application Timers section of the Admin Guide.
If you have successfully installed multiple Glassfish servers behind a load balancer you might like to know which server a user has landed on. A straightforward solution is to place a file called host.txt in a directory that is served up by Apache such as /var/www/html and then configure Apache not to proxy requests to /host.txt to Glassfish. Here are some example commands on RHEL/CentOS 7 that accomplish this:
[root@server1 ~]# vim /etc/httpd/conf.d/ssl.conf
[root@server1 ~]# grep host.txt /etc/httpd/conf.d/ssl.conf
ProxyPassMatch ^/host.txt !
[root@server1 ~]# systemctl restart httpd.service
[root@server1 ~]# echo $HOSTNAME > /var/www/html/host.txt
[root@server1 ~]# curl https://dataverse.example.edu/host.txt
server1.example.edu
You would repeat the steps above for all of your Glassfish servers. If users seem to be having a problem with a particular server, you can ask them to visit https://dataverse.example.edu/host.txt and let you know what they see there (e.g. “server1.example.edu”) to help you know which server to troubleshoot.
Please note that “Network Ports” under the Configuration section has more information on fronting Glassfish with Apache. The Shibboleth section talks about the use of ProxyPassMatch.