How to check whether clustering on JBoss AS 7 is working perfect?

[j_pramanik]

Hello All,

Can any one please tell me how to check whether clustering on JBoss AS 7.1.x is working or not ?

The problem is I have done several steps in order to implement clustering on Jboss with mod_cluster in Apache HTTP server 2.2. I'm running FOUR jboss instances under different port-offset.

The steps are as below -

in Apache HTTP Server SSL has been implemented:

1. Certificate (.pem and .crt) files are generated and copied under %APACHE_HOME%/conf folder

2. Required LoadModules lines are copied in httpd.conf file -

LoadModule proxy_module modules/mod_proxy.so

LoadModule proxy_ajp_module modules/mod_proxy_ajp.so

LoadModule slotmem_module modules/mod_slotmem.so

LoadModule manager_module modules/mod_manager.so

LoadModule proxy_cluster_module modules/mod_proxy_cluster.so

LoadModule advertise_module modules/mod_advertise.so

LoadModule proxy_http_module modules/mod_proxy_http.so

LoadModule ssl_module modules/mod_ssl.so

3. Other changes done as below -

Include conf/extra/httpd-default.conf

Include conf/extra/httpd-ssl.conf

the above lines are uncommented.

4. In httpd-ssl.conf file -

following line is added

SSLCertificateFile "C:/Program Files/Apache Software Foundation/Apache2.2/conf/server.crt"

SSLCertificateKeyFile "C:/Program Files/Apache Software Foundation/Apache2.2/conf/server.pem"

HTTP server was restarted.

Changes done in JBoss Server : Changes done in standalone-ha.xml file -

1.  <server name="node1" xmlns="urn:jboss:domain:1.2"> 

     name="nodeX" is mentioned for each of the four node for <server> tag.

2. mod_cluster is configured:

       <subsystem xmlns="urn:jboss:domain:modcluster:1.0">

            <mod-cluster-config advertise-socket="modcluster" proxy-list="127.0.0.1:6666">

                <dynamic-load-provider>

                    <load-metric type="busyness"/>

                </dynamic-load-provider>

            </mod-cluster-config>

        </subsystem>

3. Instance Id is mentioned :

       <subsystem xmlns="urn:jboss:domain:web:1.1" default-virtual-server="default-host" instance-id="${jboss.node.name}">

            <connector name="http" protocol="HTTP/1.1" scheme="http" socket-binding="http"/>

            <virtual-server name="default-host" enable-welcome-root="true">

                <alias name="localhost"/>

                <alias name="example.com"/>

            </virtual-server>

       </subsystem>

4. An application WAR is copied to %JBOSS_HOME%/standalone/deployment/  for each instance of jboss.

As FOUR jboss instances are running each jboss node is started with following commands:  (http port no. is kept same, port-offset is used different)

Node 1) E:/server1/jboss7/bin> standalone.bat -Djboss.node.name=node1 --server-config=standalone-ha.xml -Djboss.socket.binding.port-offset=100

Node 2) E:/server2/jboss7/bin> standalone.bat -Djboss.node.name=node2 --server-config=standalone-ha.xml -Djboss.socket.binding.port-offset=200

Node 3) E:/server3/jboss7/bin> standalone.bat -Djboss.node.name=node3 --server-config=standalone-ha.xml -Djboss.socket.binding.port-offset=300

Node 4) E:/server4/jboss7/bin> standalone.bat -Djboss.node.name=node4 --server-config=standalone-ha.xml -Djboss.socket.binding.port-offset=400

Now when I enter "https://localhost/<application>" on browser address bar

It shows :   localhost:8185/<application>

And, on shut down that instance again I have to enter the URL : "https://localhost/<application>"

Here I'm little bit confused whether the configuration is perfect or any further correction is required.

Can any one please suggest me what else to do? And how to confirm that configuration is done correctly ?

Thanks in advance.

Regards.

Jayanta Pramanik

[rhusar]

Hi Jayanta,

Look at the all the clustering features you are using and then verify each of them is working as you expecthem to. These minght be things like SingletonServrice, EJB3 clustering, HTTP Session replication.

I think you are mostly interested in HTTP Session replication. To perform a functional test that session is working, try something similar to:

1. Start a cluster
2. Deploy an application where the state being replicated is visible (e.g. in clusterbench (https://github.com/clusterbench/clusterbench) you see an incremented number after each invocation)
3. create HTTP session
4. fail (kill the process, simulate netowor/HW failure, whatnot) a node where the session is being kept sticky to
5. verify failover happened as expected

Rado

[bimaljh]

Hi Jayant, Please can you help me out. I am totally new to Application Server stuff and to JBoss7 AS. While starting the Apache2.2 Server I am gettting the below error

"

httpd.exe: Syntax error on line 486 of C:/Program Files/Apache Software Foundati

on/Apache2.2/conf/httpd.conf: Cannot load C:/modules/mod_proxy.so into server: T

he specified module could not be found."

Can you please provide me the steps for implementing/configuring this.

[rhusar]

Bimal, at first sight the path is wrong: you will want to copy these modules somewhere to C:/Program Files/Apache Software Foundation/Apache2.2/modules/ and also make sure you have correctly configured the paths in ServerRoot directive.

[bimaljh]

Thanks Radoslav. I was able to sort that problem, now the Apache 2.2 server is getting started( on launching localhost:8080 I get It work on the page).

Problem seems to be in clustering.

I have created 3 nodes, individually when I start the jboss nodes it is working properly but nowhere in the console I find Number of nodes/cluster : 3 and the mapping like node1|web[1]....

For clustering I have also deployed ear/war file but no success.

Please help.

Many Thanks in advance

[rhusar]

I have created 3 nodes, individually when I start the jboss nodes it is working properly but nowhere in the console I find Number of nodes/cluster : 3 and the mapping like node1|web[1]....

There is a major difference from previous versions of JBoss AS: in AS7 clustering services are only started once they are required. So unless you have deployed a clustered WebApp or other service which depends on clustering, clustering itself will not be started.

To get started, look at the JDF where you will find some clustering quickstarts you can build, use and learn from:

https://github.com/jboss-jdf/jboss-as-quickstart

[bimaljh]

Hi Radoslav, Have you configured ActiveMQ with JBoss AS7. If yes please can you provide the steps as well as the sampl MDB.ear file location to test it.

[rhusar]

Unfortunately, no, I haven't. I would try googling around.