13.2.14. Configure the mod_cluster Subsystem to Use TCP
The
mod_cluster
subsystem uses multicast UDP for its network communication by default. If you wish, you can use unicast TCP communication instead. Use the following procedure to configure this behavior.
The
mod_cluster
subsystem relies upon JGroups to manage cluster nodes and failover behaviors. You can configure the JGroups subsystem to use TCP as well. Refer to Section 13.2.13, “Configure the JGroups Subsystem to Use TCP”.
Procedure 13.6.
Modify the HTTPD configuration.
Modify the HTTPD configuration to disable server advertising and to use a proxy list instead. The proxy list is configured on the worker, and contains all of themod_cluster
-enabled HTTPD servers the worker can talk to.Themod_cluster
configuration for the HTTPD server is typically located in/etc/httpd/
or theetc/httpd/
directory within the HTTPD installation, if it is installed in a non-standard location. Refer to Section 13.3.3, “Install the mod_cluster Module Into Apache HTTPD or Enterprise Web Server HTTPD” and Section 13.3.4, “Configure Server Advertisement Properties for Your mod_cluster-enabled HTTPD” for more information about the file itself. Open the file containing the virtual host which listens for MCPM requests (using theEnableMCPMReceive
directive), and disable server advertising by changing theServerAdvertise
directive as follows.ServerAdvertise Off
Disable advertising within the
mod_cluster
subsystem of JBoss Enterprise Application Platform, and provide a list of proxies.You can disable advertising for themod_cluster
subsystem and provide a list of proxies, by using the web-based Management Console or the command-line Management CLI. The list of proxies is necessary because themod_cluster
subsystem will not be able to automatically discover proxies if advertising is disabled.Management Console
- If you use a managed domain, you can only configure
mod_cluster
in profiles where it is enabled, such as theha
andfull-ha
profiles. - Log in to the Management Console and select the Profiles label at the top right of the screen. If you use a managed domain, select either the
ha
orfull-ha
profile from the Profiles selection box at the top left of the Profiles page. - Click the Subsystems menu to expand it. Expand the Web sub-menu, and select Modcluster.
- Click the Edit button at the top, to edit the options which pertain to the entire
mod_cluster
subsystem. Change the value of Advertise tofalse
. Use the Save button to save the settings. - Click the tab labeled Proxies near the bottom of the screen. Click the Edit button in the Proxies sub-page, and enter a list of proxy servers. The correct syntax is a comma-separated list of
HOSTNAME:PORT
strings, like the following.10.33.144.3:6666,10.33.144.1:6666
Click the Save button to save your changes.
Management CLI
The following two Management CLI commands create the same configuration as the Management Console instructions above. They assume that you run a managed domain and that your server group uses thefull-ha
profile. If you use a different profile, change its name in the commands. If you use a standalone server using thestandalone-ha
profile, remove the/profile=full-ha
portion of the commands./profile=full-ha/subsystem=modcluster/mod-cluster-config=configuration/:write-attribute(name=advertise,value=false) /profile=full-ha/subsystem=modcluster/mod-cluster-config=configuration/:write-attribute(name=proxy-list,value="10.33.144.3:6666,10.33.144.1:6666")
Result
The TCP protocol is used for mod_cluster
communication by default.