= Apache HTTP Server dynamic load balancer =
== Enabling mod_cluster ==

Detailed information about configuring mod_cluster can be found here:

    https://docs.modcluster.io/#httpd

with some additional FAQ on:

    http://modcluster.io/faq/

Last but not least, we kindly invite you to join the discussion on:

    https://developer.jboss.org/en/mod_cluster


== Disable proxy_balancer_module (required) ==

To enable mod_cluster you need to make sure you have proxy_balancer_module disabled. Please comment out the loading of proxy_balancer_module in /etc/httpd/conf/httpd.conf:

    # LoadModule proxy_balancer_module

== Enable mod_cluster modules (required) ==

Next step is to load all required mod_cluster modules. Uncomment all LoadModule directives from
/etc/httpd/conf.d/mod_cluster.conf file:

    LoadModule proxy_cluster_module modules/mod_proxy_cluster.so
    LoadModule cluster_slotmem_module modules/mod_cluster_slotmem.so
    LoadModule manager_module modules/mod_manager.so
    LoadModule advertise_module modules/mod_advertise.so

Furthermore, mod_cluster needs proxy_module and proxy_ajp_module loaded for AJP transport to operate. Similarly it needs proxy_http_module loaded if one wishes to use HTTP transport instead of AJP.

== Enabling mod_cluster manager (optional) ==

Mod_cluster manager is a simple monitoring and management tool that displays useful information about workers. To enable it you need to load the mod_manager module and call SetHandler for the selected context:

<Location /mod_cluster_manager>
    SetHandler mod_cluster-manager
</Location>

== Restart ==

Make sure you restart the httpd server after you apply these changes.
See /etc/httpd/conf.d/mod_cluster.conf file for details on network configuration.

= Tomcat workers =

Simply add

    <Listener className="org.jboss.modcluster.container.catalina.standalone.ModClusterListener" advertise="true" stickySession="true" stickySessionForce="false" stickySessionRemove="true" />

to /etc/tomcat/server.xml.
You also need to set jvmRoute, i.e. the name of your worker:

    <Engine name="Catalina" defaultHost="localhost" jvmRoute="tomcat-worker-1">

Last but not least, on virtual machines, you might experience _very_ slow start of Tomcat
due to lack of entrophy. For testing purposes, you might choose insecure random number provider:

    -Djava.security.egd=file:///dev/urandom

to CATALINA_OPTS or /usr/libexec/tomcat/server

= WildFly workers =

mod_cluster is available as a subsystem in standalone-ha.xml. To enable it, set:

    WILDFLY_CONFIG=standalone-ha.xml

in /etc/wildfly/wildfly.conf