This section explains the best way to configure the IBM Edge components Load Balancer (IPv4 & IPv6) to balance the client requests of IBM Connections 4. We explain the configuration steps on a Linux operating system, though Microsoft Windows, AIX, HP-UP, and Solaris systems are supported as well.
The following figure shows the network topology of our lab environment.
In this topology, we include one WebSphere Edge Load Balancer 6.1 component for balancing the incoming HTTP connections for two HTTP servers. We use the same topology for Edge Caching Proxy servers.
In lab scenario, we have installed WebSphere Edge Load Balancer and assigned two static IP addresses are assigned to it. For the Load Balancer system, note the following:
- The server selected for the Load Balancer installation must reside on the same LAN segment as the nodes to be clustered.
- Ensure that /opt/ibm/edge/ulb/bin is added to the PATH.
Configuring the WebSphere Edge Load Balancer
Use the following steps to configure the WebSphere Edge Load Balancer:
- Start the server function by running the following command on a command prompt:
- Stop the executor function using the following command:
dscontrol executor stop
- Change Log level to 1 using the following command:
dscontrol set loglevel 1
- Start the executor function using the following command:
dscontrol executor start
- Set nfa IP address:
dscontrol executor set nfa 10.52.78.36
- Define a cluster and set cluster options:
dscontrol cluster add 10.52.78.28
dscontrol cluster set 10.52.78.28 proportions 49 50 1 0
dscontrol executor configure 10.52.78.28M
The dispatcher balances the requests from clients to the servers configured behind dispatcher. The cluster is either the symbolic name, the dotted decimal address, or the special address 0.0.0.0 that defines a wildcard cluster. Wildcard clusters can be used to match multiple IP addresses for incoming packets to be load balanced.
- Define ports and set port options with the adding dscontrol port command, dscontrol port add cluster@port. For example:
dscontrol port add 10.52.78.28@80
- Define the load-balanced server machines. To define a load-balanced server machine, run the following command:
dscontrol server add 10.52.78.28@email@example.com
dscontrol server set 10.52.78.28@firstname.lastname@example.org weight 14
dscontrol server add 10.52.78.28@email@example.com
dscontrol server set 10.52.78.28@firstname.lastname@example.org weight 14
- Repeate the steps 6 and 7 to setup dispatcher in port 443 used by https protocol.
dscontrol port add 10.52.78.28@443
dscontrol server add 10.52.78.28@email@example.com
dscontrol server set 10.52.78.28@firstname.lastname@example.org weight 14
dscontrol server add 10.52.78.28@email@example.com
dscontrol server set 10.52.78.28@firstname.lastname@example.org weight 14
- Start the manager function to improves load balancing. To start the manager, run the following command:
dscontrol manager start manager.log 10004
- Start the advisor function. The advisors give the manager more information about the ability of the load-balanced server machines to respond to requests.
dscontrol advisor start http 80 http_80.log
dscontrol advisor start https 443 http_443.log
Configuring the HTTP Servers servers
The HTTP Servers servers need configuration changes for the Load balancing to work. The Dispatcher only balances requests across servers that allow the loopback adapter to be configured with an additional IP address, for which the back-end server will never respond to ARP (address resolution protocol) requests.
In Linux to configure a loopback interface you must run the following command:
ip -4 addr add 10.52.78.28/32 dev lo
Remember to run this command in both HTTP servers.
For information about configuring loopback on a Microsoft Windows environment, see Edge Components Info Center
Your Load Balancer is now configured and ready to use. For information on managing your Load Balancer, a full list of advisors, metric server functions for Dispatcher, and other advanced features, refer to the product documentation that comes with the Load Balancer.