Apache mod_proxy balancer config issue with POST request

[Tech P]

I am trying to setup a Load balancer with Apache mod_proxy and Tomcat.
I have the following modules available (mod_proxy, mod_proxy_balancer, mod_proxy_http)
I have 2 Tomcat instances and the plan is to route the request to one of the Tomcat server.

My application on Tomcat is running fine when I directly access.
www.mydomain:8080/myapp
www.mydomain:9080/myapp

My Tomcat server.xml has the following
Tomcat 1
<Connector port="8009" protocol="AJP/1.3" redirectPort="8443" />
<Engine name="Catalina" defaultHost="localhost" jvmRoute="tomcat1">

Tomcat 2
<Connector port="9009" protocol="AJP/1.3" redirectPort="9443" />
<Engine name="Catalina" defaultHost="localhost" jvmRoute="tomcat2">

Here is what I have in my virtualhost.conf

<IfModule proxy_module>
ProxyRequests on
ProxyPreserveHost Off
ProxyPass / balancer://mycluster/ stickysession=JSESSIONID
ProxyPassReverse / balancer://mycluster/ stickysession=JSESSIONID
ProxyPassReverseCookiePath /myapp /

<Proxy balancer://mycluster >
BalancerMember http://localhost:8080/myapp route=tomcat1
BalancerMember http://localhost:9080/myapp route=tomcat2

Require all granted
ProxySet lbmethod=byrequests
</Proxy>

<Location /balancer>
SetHandler balancer
Require host www.mydomain.com
</Location>
</IfModule>

With the above configuration I am able to access the site first page. When I access www.mydomain.com, it loads the login page(www.mydomain.com/login.do)
When I click on other links it's opening the correct pages. For eg: www.mydomain.com/password-reset.do
The basic fail over also works. If I shutdown one Tomcat Instances, it serves the page from the other server and vice versa.

But when I try to submit any POST requst like try to Login, the url change to www.mydomain/myapp/login.do and always shows the login page.

I am not sure the above conf entries are fully correct with respect to what I want.
Can some one points me what is wrong. Also please let me know if I am lacking anything here with respect to sucurity.
I also would like to have image files and other files served directly from the Webserver. Please let me know how I can do that.

Thanks in advance

 

[Tech P]

Hi,
I am trying to set up a Load balancer configuration with Apache and Tomcat.
I am on a Virtual Private Server with CentOS 6.9 and I use cPanel. Here is my questions.

1. What are the options I have for load balancing?

2. For Load balancer what is preferred between mod_jk and mod_proxy? Also any other good options? I have found that my configuration doesn't come with mod_jk and noticed that cPanel documentation says it is not recommended because of security reasons.

3. Looks like any changes I make directly to the Apache /usr/local/apache/conf/httpd.conf will be overwritten when any cPanel setting is changed. So what is the best way if we want to modify VirtualHost settings? Where I should make the changes? I have seen several conf files and not sure which is the right one.
Also if I need to make any changes outside the VirtualHost entry which is the right file or where should I create the file?
When I create the cPanel user those VirtualHost entries are made automatically. So I am assuming in order to configure load balancer, I need update the files manually to have additional attributes in the VirtualHost entry.

4. What is the purpose of the following Apache directories?
/usr/local/apache
/etc/apache2
/etc/httpd

Thanks

 

[cPanelMichael]

Hello @Tech P,

We don't currently support load balancing with cPanel & WHM. Any type of load balancing configuration is unsupported, and thus you'd need to seek out the help of a qualified system administrator if it's not working the way you intend or if you require assistance with the setup. We provide a list of companies offering system admin services at:

System Administration Services | cPanel Forums

Additionally, I encourage you to vote and add feedback to the following feature requests if you'd like to see load balancing supported in cPanel & WHM:

Server configuration and data auto-sync (mirroring)
Active-Active Redundancy or High-availability
Built-in load balancing, replication, high availability

Note that our feature request website is currently down for maintenance but should resume operation soon.

With that said, I'm happy to answer questions related to the cPanel & WHM product itself:

3. Looks like any changes I make directly to the Apache /usr/local/apache/conf/httpd.conf will be overwritten when any cPanel setting is changed. So what is the best way if we want to modify VirtualHost settings? Where I should make the changes? I have seen several conf files and not sure which is the right one.
Also if I need to make any changes outside the VirtualHost entry which is the right file or where should I create the file?
When I create the cPanel user those VirtualHost entries are made automatically. So I am assuming in order to configure load balancer, I need update the files manually to have additional attributes in the VirtualHost entry.

We document advanced Apache configuration information (including what to edit to ensure changes are not overwritten) at:

Advanced Apache Configuration - EasyApache 4 - cPanel Documentation

4. What is the purpose of the following Apache directories?
/usr/local/apache
/etc/apache2
/etc/httpd

The /etc/apache2/ and /usr/local/apache/ directories are where required Apache data is stored (e.g. domain access logs, configuration files). In many cases, data within /usr/local/apache/ is symbolically linked to the corresponding location in the /etc/apache2/ directory. As far as /etc/httpd, it's not a file or directory that's setup by default on cPanel & WHM when using EasyApache 4.

Thank you.