4 Replies Latest reply on Nov 23, 2016 4:42 PM by emeuwese

    Domain with load-balancer and worker nodes on single host?

    _bojan
    _bojan Oct 2, 2016 11:41 PM

      Hi,

      I am trying to set up a domain with a load balancer and two worker instances on the same host for testing purposes.

      According to WildFly 10.1 is now available! · WildFly,

      'You can now build a fully clustered topology using just our default profiles in domain mode, creating a server with the "load-balancer" profile, and a set of backend servers using the "full-ha" profile."

      It does not mention anything about the number of hosts, so I am trying to see if this works on a single host, i.e. master.

       

      I followed a tutorial by karm  over at Undertow mod_cluster proxy: Basic setup in Wildfly 10 - asciinema and was able to set up  a similar scenario using 3 standalone instances on a single machine, where one acts as mod-cluster balancer. But since domain mode already has the load-balancer profile, I figured it would be easy to do in domain mode.

       

      I downloaded Wildfly 10.1, started up the domain and removed default server groups from the domain.

      I created a lb-group, with load-balancer profile and load-balancer-sockets, as well as app-nodes group, with full-ha profile and full-ha-sockets.

      I then created a load-balancer server in lb-group with port offset of 0.

      In app-nodes group, I created two worker instances, server-one and server-two with port offsets of 100 and 200, respectively.

      I deployed a sample.war and assigned it to app-nodes group. I can access http://localhost:8180/sample and http://localhost:8280/sample fine, but when I try to use the load balancer, http://localhost:8080/sample, I get a 404 error.

       

      Log messages relating to modcluster on load-balancer instance:

      Undertow starts mod_cluster proxy advertisements on /224.0.1.105:23364 with frequency 10000 ms

      and on app-nodes instances:

       INFO  [org.jboss.modcluster] (ServerService Thread Pool -- 69) MODCLUSTER000001: Initializing mod_cluster version 1.3.3.Final
 INFO  [org.jboss.modcluster] (ServerService Thread Pool -- 69) MODCLUSTER000032: Listening to proxy advertisements on /224.0.1.105:23364

       

      I tried different port offsets, as well as using ha-profile instead of full-ha for worker instances, but the result is the same.

      How can I get this up and running? Any help is greatly appreciated.

        • 1. Re: Domain with load-balancer and worker nodes on single host?
          rhatlapa
          rhatlapa Oct 3, 2016 4:47 AM (in response to _bojan)

          It probably just doesn't work because you are running the servers on localhost. Please try to run them on your public IP addresses and see if that helps.

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          • 2. Re: Domain with load-balancer and worker nodes on single host?
            _bojan
            _bojan Oct 3, 2016 9:31 AM (in response to rhatlapa)

            Hi,

            Thanks for the reply.

            I tried in a few different ways; via Docker containers and physical machines, but I could not get load balancer to work in domain mode with load-balancer profile, even when the balancer instance is on a different host than the domain controller. I still get a 404 when accessing the application.

            These methods used to work when I would use Apache with mod_cluster module, but I would really like to use Undertow instead.

            I will try to see what is different about domain mode load-balancer profile and the configuration from karm's tutorial for standalone mode.

            If I figure it out, I will post the answer. If anyone has any other suggestions, I am all in for trying out different approaches.

            Thanks.

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            • 3. Re: Domain with load-balancer and worker nodes on single host?
              _bojan
              _bojan Oct 3, 2016 12:47 PM (in response to _bojan)

              I found what was causing the problem.

              In load-balancer-sockets binding group, binding for modcluster was tied to private interface. I removed interface="private" and the balancer could register the nodes via ajp.

               

              Hope it may help save someone some time when setting up a local testing environment.

              1 of 1 people found this helpful
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              • 4. Re: Domain with load-balancer and worker nodes on single host?
                emeuwese
                emeuwese Nov 23, 2016 4:42 PM (in response to _bojan)

                I experienced this too. With the interface from mcmp-management and modcluster set to public I got it working.

                domain.xml:

                <socket-binding-groups>
     ...
     <socket-binding-group name="load-balancer-sockets" default-interface="public">
          ...
          <socket-binding name="mcmp-management" interface="public" port="${jboss.mcmp.port:8090}"/>
          <socket-binding name="modcluster" interface="public" multicast-address="224.0.1.105" multicast-port="23364"/>
          ...
     </socket-binding-group>
</socket-binding-groups>
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