1 Reply Latest reply on Nov 24, 2014 4:25 AM by Jean-Frederic Clere

    What is mean by Host in Mod Cluster ?

    Arun Raj Expert

      Hi ,

      I got the error "manager_handler CONFIG error: MEM: Can't update or insert node". When i have tried to troubleshoot the issue, I got confused with the terminology of modcluster.

       

      I am having confusion with Host property (Maxhost) in Modcluster. Since I am using two Host in JBoss EAP Side. So I though i am having two host in my environment. But I have seen more than 20 hosts by hitting "show dump output" button

       

       

      host: 1 [example.com] vhost: 1 node: 15

      host: 2 [default-host] vhost: 1 node: 15

      host: 3 [example.com] vhost: 1 node: 8

      host: 4 [default-host] vhost: 1 node: 8

      host: 5 [example.com] vhost: 1 node: 3

      host: 6 [default-host] vhost: 1 node: 3

      host: 7 [example.com] vhost: 1 node: 7

      host: 8 [default-host] vhost: 1 node: 7

      host: 9 [example.com] vhost: 1 node: 13

      host: 10 [default-host] vhost: 1 node: 13

      host: 11 [example.com] vhost: 1 node: 2

      host: 12 [default-host] vhost: 1 node: 2

      host: 13 [example.com] vhost: 1 node: 12

      host: 14 [default-host] vhost: 1 node: 12

      host: 17 [example.com] vhost: 1 node: 4

      host: 18 [default-host] vhost: 1 node: 4

      host: 19 [example.com] vhost: 1 node: 20

      host: 20 [default-host] vhost: 1 node: 20

      host: 21 [example.com] vhost: 1 node: 19

      host: 22 [default-host] vhost: 1 node: 19

      host: 23 [example.com] vhost: 1 node: 9

      host: 24 [default-host] vhost: 1 node: 9

      host: 25 [example.com] vhost: 1 node: 6

      host: 26 [default-host] vhost: 1 node: 6

      host: 27 [example.com] vhost: 1 node: 1

      host: 28 [default-host] vhost: 1 node: 1

      host: 29 [example.com] vhost: 1 node: 11

      host: 30 [default-host] vhost: 1 node: 11

       

      Can you please explain Why I am having 30 host in my mod cluster configuration ? Any help is much appreciated.

       

      Thanks & Regards,
      ArunRaj. R

        • 1. Re: What is mean by Host in Mod Cluster ?
          Jean-Frederic Clere Master

          The Host are the virtual-host defined in the standalone.xml and in the webapps (basically a group of aliases). Each webapp can have its own aliases resulting in a Host created per webapp, but normally that isn't the case...

          The Node correspond to the 2 boxes you are running.

          It looks like you have something wrong because you have 20 nodes and only 2 boxes :-(

           

          There can be several reasons to have that:

          1 -The advertise of mod_cluster reach 20 boxes that are in your lab.

          2 - Something wrong in the CONFIG message creates more nodes than excepted.

           

          To test that check the nodes and the CONFIG messages in error_log once the log level is debug.