Hi,

Here is a simple step by step procedure to connect to JBoss instance for load balancing purpose through apache webserver. In most of the production environments this is the most common need.

The prerequisite for this exercise is to have the the Apache WebServer installed already in your Machine and the JBoss should be installed in your environment. The “mod_jk” module can be downloaded later to work on this setup. If you want to download the apache software and the mod_jk then you can refer to the link mentioned in the Step6):

JBoss Cluster Creation/Configuration Part:

Step1). As “all” and “production” profiles which are present inside the “E:jboss-AS6-5.1jboss-asserver” location are by default clustering enabled so you can chose any one of them to create your own clustered node. In this exercise we will use “all” profile to create JBoss Clusters.

So first copy the “all” profile and paste it in the same location “E:jboss-AS6-5.1jboss-asserver” with some different name like “all_node1″ and “all_node2″. like this your 2 JBoss Clustered Nodes are ready.

Step2). Now open the “server.xml” file present inside the “E:jboss-AS6-5.1jboss-asserverall_node1deployjbossweb.sar” location and then add the “jvmRoute” attribute of the Engine Tag like following:By default the line which you are going to change will look like following:
=============By default it will look like below==================

<Engine name="jboss.web" defaultHost="localhost">

=============After Change it will look like below==================

<Engine name="jboss.web" defaultHost="localhost" jvmRoute="node1">

Step3). Same changes we need to do for “all_node2″ profile as well. So open the “server.xml” file present inside the “E:jboss-AS6-5.1jboss-asserverall_node2deployjbossweb.sar” location and then add the “jvmRoute” attribute of the Engine Tag like following:
=============By default it will look like below==================

<Engine name="jboss.web" defaultHost="localhost">

=============After Change it will look like below==================

<Engine name="jboss.web" defaultHost="localhost" jvmRoute="node2">

Why We need “jvmRoute”?

jvmRoute Identifier must be used in load balancing scenarios to enable session affinity. The identifier, which must be unique across all Tomcat 6 servers which participate in the cluster, will be appended to the generated session identifier, therefore allowing the front end proxy to always forward a particular session to the same Tomcat 6 OR JBoss instance.

More information regarding this attribute can be found in the following link:
http://tomcat.apache.org/tomcat-6.0-doc/config/engine.html#Common_Attributes

Step4). Also please make sure that the AJP Connector Tag is uncommented in “E:jboss-AS6-5.1jboss-asserverall_node2deployjbossweb.sarserver.xml” file for both “all_node1″ & “all_node2″ profiles, Because the communication between Apache and JBoss will happen through this AJP connector port. Like following:

      <!-- A AJP 1.3 Connector on port 8009 -->
      <Connector protocol="AJP/1.3" port="8009" address="${jboss.bind.address}"
         redirectPort="8443" />

Step5). Now start Both the JBoss Instances by running the following command from the following dir “E:jboss-AS6-5.1jboss-as\bin”:

run.bat -c all_node1 -b 0.0.0.0 -g ClusterA -Djboss.service.binding.set=ports-01 -Djboss.messaging.ServerPeerID=1
run.bat -c all_node2 -b 0.0.0.0 -g ClusterA -Djboss.service.binding.set=ports-02 -Djboss.messaging.ServerPeerID=2

Here following are the meaning of the flags which we have used :
-c = The jboss profile which we want to start

-g = The name of the cluster. The same name of the cluster should be used by the profiles which want to join the same cluster formation.

-Djboss.service.binding.set = The advantage of this way is you don’t have to take (and maintain) a separate copy of the all folder if you want to, say, start up multiple instances of JBoss running as a cluster. For more information on this system property please refer to the following : http://community.jboss.org/wiki/ConfigurePorts

-Djboss.messaging.ServerPeerID = Each node must have a unique ServerPeerID for clustering to work!. It can be any unique integer value among all the cluster members. Means every cluster node should have a unique peer ID.

-b = The bind address in which you want to run your profile. o.o.o.o represents it will listen to all the IP Addresses associated with that box. better if we can specify a particular “IP Address” or “localhost” there rather than using “0.0.0.0″

So suppose if you are running your JBoss on two separate physical boxes which has different IP Addresses like 10.10.10.10 and 20.20.20.20 then please run the servers like following

run.bat -c all_node1 -b 10.10.10.10 -g ClusterA -Djboss.service.binding.set=ports-01 -Djboss.messaging.ServerPeerID=1
run.bat -c all_node2 -b 20.20.20.20 -g ClusterA -Djboss.service.binding.set=ports-02 -Djboss.messaging.ServerPeerID=2

Apache WebServer Configuration Part:

Step6). Download & Install the apache webserver from the following link along with the “mod_jk” file:
http://docs.redhat.com/docs/en-US/JBoss_Enterprise_Web_Platform/5/html/Administration_And_Configuration_Guide/clustering-http.html#clustering-http-modjk

Step7). Now paste the “mod_jk.so” file inside the modules directory of your apache which may be “C:Program FilesApache GroupApache2modules”

Step8). Now add the following line of configuration somewhere at the bottom inside your “C:Program FilesApache GroupApache2confhttpd.conf” file to include the mod_jk configuration file:

##### JBOSS #############
LoadModule jk_module modules/mod_jk.so

# Include mod_jk's specific configuration file
Include conf/mod_jk.conf
###########################

Step9). Now create a file with name “mod_jk.conf” inside the directory “C:Program FilesApache GroupApache2conf” as following:

##### JBOSS #############
# Load mod_jk module
# Specify the filename of the mod_jk lib
LoadModule jk_module modules/mod_jk.so

# Where to find workers.properties
JkWorkersFile conf/workers.properties

# Where to put jk logs
JkLogFile logs/mod_jk.log

# Set the jk log level [debug/error/info]
JkLogLevel info

# Select the log format
JkLogStampFormat  "[%a %b %d %H:%M:%S %Y]"

# JkOptions indicates to send SSK KEY SIZE
JkOptions +ForwardKeySize +ForwardURICompat -ForwardDirectories

# JkRequestLogFormat
JkRequestLogFormat "%w %V %T"

# Mount your applications
JkMount /* failover

# You can use external file for mount points.
# It will be checked for updates each 60 seconds.
# The format of the file is: /url=worker
# /examples/*=loadbalancer
#JkMountFile conf/uriworkermap.properties

# Add shared memory.
# This directive is present with 1.2.10 and
# later versions of mod_jk, and is needed for
# for load balancing to work properly
JkShmFile logs/jk.shm

# Add jkstatus for managing runtime data
<Location /jkstatus/>
    JkMount status
    Order deny,allow
    Deny from all
    Allow from 127.0.0.1
</Location>
###########################

Step10). Now create another most important file “worker.properties” inside “C:Program FilesApache GroupApache2conf” to tell apache to load balance between what all nodes of the JBoss clusters:

##### JBOSS #############
# Define list of workers that will be used
# for mapping requests
worker.list=failover
#,status

# Define Node2
# modify the host as your host IP or DNS name.
worker.node2.port=8209
worker.node2.host=20.20.20.20
worker.node2.type=ajp13
worker.node2.ping_mode=A
worker.node2.lbfactor=1

# Define Node1
# modify the host as your host IP or DNS name.
worker.node1.port=8109
worker.node1.host=10.10.10.10
worker.node1.type=ajp13
worker.node1.ping_mode=A
worker.node1.lbfactor=1

# Load-balancing behaviour
worker.loadbalancer.type=lb
worker.loadbalancer.balance_workers=node2,node1
worker.loadbalancer.sticky_session=False
worker.list=loadbalancer

# Status worker for managing load balancer
#worker.status.type=status
###########################

NOTE: Make sure that you are setting the correct “Hostname” and “AJP Port” for your JBoss in the above file.

Step 11). Now restart your apache server and then hit the following URL to access the JBoss:

http://localhost/jmx-console

OR

http://localhost/admin-console

.
.
Thanks
Middleware Magic