mod_jk to load balance between multiple Clusters , jBoss 4.2.3

[whizkid.samrat]

Hi ,

I am farely new to clustering, but i have been able to cluster my application server and used mod_jk for load balencing. So far so good , but now my application will interact with another application which runs it's own cluster and sends request to my application over http.

Here is the problem :

My application AppA is using jBoss 4.2.3 and has two nodes - Node1 and Node2  and the  cluster partition name is partitionA , the other application AppB is using jBoss 4.0.2 and has it's nodes - Nodes 3 , Node 4 and the name of the cluster is partitionB.

All 4 nodes (2 nodes for partitionA and 2 nodes for partitionB) are housed in the same physical server running four instances of jvm .

I have only one instance of loadbalancer ( Apacle 2.0 with mod_jk 1.2) on port 80.

I have 4 workers configured in workers.properties

# Load-balancing behaviour

worker.loadbalancer.type=lb

worker.loadbalancer.balance_workers=node1,node2,node3,node4

worker.loadbalancer.sticky_session=1

#worker.list=loadbalancer

Now in the uriworkermap.properties I state the following.

# Mount the Servlet context to the ajp13 worker

/AppA=loadbalancer

/AppA/*=loadbalancer

/AppB=loadbalancer

/AppB/*=loadbalancer

Nowhere do I mention AppA is running on PartitionA and AppB is running on PartitonB ?

So how does mod_jk figure out which request to send to which cluster ? how do i go about configuring this senario .. Any leads will be most helpfull.

[rhusar]

Hi Samrat,

great question. The answer is "mod_jk domains". The domain is the concept that will allow loadbalancer to indentify which nodes to failover on to. So in your case 1->2, 2->1, 3->4 or 4->3. You will have to configure property worker.node1.domain=group1 for your workers.


Check out this document to see how to configure https://community.jboss.org/wiki/LoadBalancingWithModjkDomainDirective

HTH,

Rado

[whizkid.samrat]

Thanks Radoslav for your answer , I however did figure out a parallel way of acheving the same thing. Here are my config files :

Workers.Properties :

worker.list=hrisloadbalancer,cesLoadBalancer,status

worker.template.type=ajp13

worker.template.prepost_timeout=10000

worker.template.connect_timeout=10000

worker.template.socket_connect_timeout=10000

worker.template.connection_pool_size=10

worker.node1.reference=worker.template

worker.node1.host=10.8.100.118

worker.node1.port=18009

worker.node2.reference=worker.template

worker.node2.host=10.8.100.118

worker.node2.port=28009

worker.cssonode1.reference=worker.template

worker.cssonode1.host=10.8.100.118

worker.cssonode1.port=38009

worker.cssonode2.reference=worker.template

worker.cssonode2.host=10.8.100.118

worker.cssonode2.port=48009

worker.hrisloadbalancer.type=lb

worker.hrisloadbalancer.balance_workers=node1,node2

worker.hrisloadbalancer.sticky_session=True

worker.cesLoadBalancer.type=lb

worker.cesLoadBalancer.balance_workers=cssonode1,cssonode2

worker.cesLoadBalancer.sticky_session=True

worker.status.type=status

uriworkermap.properties :

# Simple worker configuration file

# Mount the Servlet context to the ajp13 worker

/jmx-console=hrisloadbalancer

/jmx-console/*=hrisloadbalancer

/web-console=hrisloadbalancer

/web-console/*=hrisloadbalancer

/hrms=hrisloadbalancer

/hrms/*=hrisloadbalancer

# Route request to loadbalancer for CES

/CES=cesLoadBalancer

/CES/*=cesLoadBalancer