Apache : Proxy Balancer, Send certain requests on both channels - apache

Question

I am working on a Spring-MVC based application which is running behind an Apache instance with reverse proxy. Currently, the setup works good with database related operations, but there are certain URL's, which when called, I would like to send request to both the servers. Example : /onlinestatus/*. If the user is currently on server1, then with our current setup, he is unaware of user on server2. But this is not correct, as both users are using the same platform. How can I instruct apache to pass certain URL's to both the platforms. Thank you.
sites-enabled/000-default :
<VirtualHost *:443>
ServerName www.domain.de
ProxyRequests off
ProxyPreserveHost On
ProxyPass /nagios !
ProxyReceiveBufferSize 4096
ErrorDocument 503 /error/message.html
ProxyPass /error/ !
ProxyPass /error/message.html !
SSLEngine on
SSLProxyEngine on
SSLCertificateFile /etc/letsencrypt/live/www.domain.de-0002/cert.pem
SSLCertificateKeyFile /etc/letsencrypt/live/www.domain.de-0002/private.key
SSLCertificateChainFile /etc/letsencrypt/live/www.domain.de-0002/chain.pem
SSLProxyVerify none
SSLProxyCheckPeerCN off
ProxyPass / https://localhost:8443/
ProxyPassReverse / https://localhost:8443/
<Location / >
SetEnvIf Origin ^(https?://.+\.DOMAIN\.de(?::\d{1,5})?)$ CORS_ALLOW_ORIGIN=$1
Header append Access-Control-Allow-Origin %{CORS_ALLOW_ORIGIN}e env=CORS_ALLOW_ORIGIN
Header merge Vary "Origin"
Order allow,deny
Allow from all
</Location>
ProxyPass / balancer://mycluster/ stickysession=JSESSIONID nofailover=On
<Proxy balancer://mycluster>
BalancerMember https://SERVER_1_IP:8443 route=server1
</Proxy>
ProxyPass /balancer-manager !
ProxyPass / balancer://mycluster/
</VirtualHost>

Answer 1

You can't proxy a request to two servers. What would you expect to get? Two HTML documents? (and what if your cluster grows: 20 HTML documents?) How would they display?
If your application works in a cluster, and it's vital that users are aware of others working on the cluster, you'll need to make that information available on the business layer (by keeping track on logged in users in the backend - this could be the database or a cluster communication channel)
If you "just" need this information for system administration purposes - e.g. to know when it's safe to take one of the cluster machines out of service - then just utilize your loadbalancer's status information page.