Configure IBM® Load
Balancer on a server running Microsoft™ Windows™.
Before you begin
Install IBM Load
Balancer and assign two static IP addresses to it. The server selected
for the Load Balancer installation must reside on the same LAN segment
as the nodes to be clustered.
About this task
Configure IBM Load
balancer to support your cluster using MAC Address rewriting. With
this method, the load balancer receives a packet intended for the
cluster. It uses configured metrics to determine which node in the
cluster should process the message, and then sends the message back
out to the network, routing it to the appropriate node's MAC address.
Each
of the nodes in the cluster is configured with a loopback adapter;
when the packet is rewritten to the network, the appropriate node
will receive and process the packet.
Procedure
- Configure the nodes of the cluster.
Add a
loopback adapter with the IP address of the cluster on each of the
nodes of the cluster. For instructions, see the Load Balancer Administration Guide, which
can be downloaded from the WebSphere® Application
Server - Edge Components site.
- Configure port settings on the cluster nodes so that IBM Load Balancer can route the
packets properly:
Attention: IBM Load Balancer requires every node in the
cluster to use same port number for STUN (typically, port 3478). If
you have configured your nodes to use different port numbers, change
them to the same port now.
- On the load balancer server, configure load balancing for
the cluster:
- Open a command window on the load balancer server.
- Start the load balancer's Dispatcher process by
clicking . right-click IBM Dispatcher (ULB),
and then click Start.
- If you are using IPv6 addresses, enable the processing
of IPv6 packets:
Run the following command while logged
in as the Windows administrator:
netsh interface ipv6 install
This
command enables processing of IPv6 packets. Issue this command only
once; thereafter, you can start and stop the executor as often as
you need. If you do not issue the command to enable processing of
IPv6 packets on these systems, the executor will not start.
- Start the executor function of the dispatcher:
- Add the cluster to the service:
dscontrol cluster add cluster's_fully_qualified_host_name
where
cluster's_fully_qualified_host_name is
the fully qualified host name that you assigned to the cluster when
you installed the load balancer; for example:
stms-cluster.example.com
.
- Add the cluster port:
dscontrol port add cluster's_fully_qualified_host_name@port
where cluster's_fully_qualified_host_name@port is
the fully qualified host name that you assigned to the cluster when
you installed the load balancer, with the TURN port appended to it
(typically port 3478); for example:
st-turn-cluster.example.com@3478
- Add the nodes for which this server will balance workload:
dscontrol server add cluster_host@port@primary_node
dscontrol server add cluster_host@port@secondary_node
where:
- Add the cluster to the executor:
dscontrol executor add cluster's_fully_qualified_host_name
where
cluster's_fully_qualified_host_name is
the fully qualified host name that you assigned to the cluster when
you installed the load balancer; for example:
stms-cluster.example.com
.
- Start the manager:
- Now you can stop the service:
- Close the command window.
- (Optional) Define server affinity with a "sticky time":
The dispatcher component of IBM Load
Balancer supports a configurable "sticky time". This means that the
load balancer will remember which cluster member a client was routed
to; subsequent requests will "stick to" the same server until the
preset time expires. The sticky time defaults to 0 seconds and there
is really no need to modify it for STUN requests. If you do want to
increase the sticky time, follow these steps:
- Start IBM Load
Balancer.
- In the navigation tree, select the Executor (the
load balancer's non-forwarding IP address, which appears under
its host name).
- Click Configuration Settings.
- In "Port-Specific Settings", change the Default
sticky-time settings from 0 to 60 seconds, and click Update
Configuration.
- Leave IBM Load
Balancer open for the next step.
- Save the load balancer settings:
- In IBM Load Balancer,
return to the navigation tree and right-click on the host name of
the load balancer you just configured (for example,
loadbal.example.com
).
- Click Save Configuration File as and
accept the default name (
default.cfg
).The
configuration settings stored in default.cfg
are
restored every time the server is restarted.
- Click OK.