Configuring Change Management Server (CM Server) load balancing for ClearQuest Web with IBM HTTP Server

Answer

This technical note describes a CM Server load balancing configuration for ClearQuest Web with two CM Servers by using IHS.


Configuration:

- 2 ClearQuest Web Servers/CM Servers

Two application servers with ClearQuest Web and CM Server installed (MachineA and MachineB in the following example)

- 1 IBM HTTP Server

Load balancer with ClearQuest Web and CM Server installed (Machine A in the following example)

- MachineA:

Installed software: ClearQuest 7.1.0.0 or later with IHS, ClearQuest Web, and CM Server
Runtime software: ClearQuest Web Server, CM Server, and IHS are active
Use: IHS load balancer and ClearQuest Web Server and CM Server host

- MachineB:

Installed software: ClearQuest 7.1.0.0 or later with IHS, ClearQuest Web, and CM Server
Runtime software: ClearQuest Web Server and CM Server are active; IHS is disabled
Use: ClearQuest Web Server and CM Server host

Step 1: Configure the IHS Load Balancer
Modify the file server.xml on each CM Server and the file plugin-cfg.xml on the IHS server.

1.1 Modify server.xml on each CM Server

Modify the file server.xml on each CM Server in the configuration. In the following example, we modify server.xml on MachineA and MachineB.


1. Open the file server.xml in a text editor.

On the UNIX system and Linux, the default location of server.xml is:

/opt/rational/common/CM/profiles/cmprofile/config/cells/dfltCell/nodes/dfltNode/servers/server1/server.xml

On Windows, the default location of server.xml is:

7.1.0.x:
C:\Program Files\IBM\RationalSDLC\common\CM\profiles\cmprofile\config\cells\<hostname>CMProfileNode01Cell\nodes\<hostname>CMProfileNode01\servers\server1/server.xml

7.1.1 and later:
C:\Program Files\IBM\RationalSDLC\common\CM\profiles\cmprofile\config\cells\dfltCell\nodes\dfltNode\servers\server1/server.xml

2. Locate the following element in the WebContainer section of the file:


<components xmi:type="applicationserver.webcontainer:WebContainer" xmi:id="webcontainer_1225386837920" …>


3. Add the following properties in the <components> element:

<properties xmi:id="Property_1225386837920" name="HttpSessionCloneId" value="12345" required="false"/>


where:

o The numeric portion (1225386837920) of the xmi:id must match the numeric portion of the xmi:id values in the WebContainer section.

o The value assigned to the value property is a unique identifier that you create for the application server in the cluster. Note this CloneID value for further use.

For simplicity, value is set to the last half of the IP address. For example, the value of the CM Server running on MachineA is set to “112097" because the IP address of MachineA is 9.34.112.97.

4. Save and close the server.xml file.

5. On the UNIX system and Linux: If you want to prevent Web access to the application server, rename S99ihs_startup in the /etc/rc3.d directory to K99ihs_startup and stop the HTTP server.

6. Restart either the CM Server host system or the CM Server by using the start and stop scripts.


1.2 Modifying plugin-cfg.xml on the IHS server

Modify the file plugin-cfg.xml on the IHS server. In this example, MachineA is the IHS server:

1. Open the file plugin-cfg.xml in a text editor.

The default path on the UNIX system and Linux is:

/opt/rational/common/eWAS/profiles

The default path on Windows is:

C:\Program Files\IBM\RationalSDLC\common\eWAS\profiles

2. Locate the following section in the file plugin-cfg.xml:


<ServerCluster Name="cmprofile_Cluster">
<Server Name="server1">
<Transport Hostname="localhost" Port="12080" Protocol="http"/>
</Server>
</ServerCluster>


3. Replace the ServerCluster section just mentioned with the following section:


<ServerCluster CloneSeparatorChange="false" Name="cmprofile_Cluster" RetryInterval="60" LoadBalance="RoundRobin">
<Server CloneID="112097" ConnectTimeout="20" LoadBalanceWeight="1" Name="server1">
<Transport Hostname="MachineA" Port="12080" Protocol="http"/>
</Server>
<Server CloneID="112096" ConnectTimeout="20" LoadBalanceWeight="1" Name="server2">
<Transport Hostname="MachineB" Port="12080" Protocol="http"/>
</Server>

<PrimaryServers>
<Server Name="server1"/>
<Server Name="server2"/>
</PrimaryServers>
</ServerCluster>

where:

-- The CloneID values must match the values of the applicationserver.webcontainer property assigned to each application server in the WebContainer section of the file server.xml, as described in the previous section.

-- The Hostname values must match the host names of the CM Servers.

4. Modify the number of server entries to match the number of application servers in your load balancing configuration.

5. Save and close the file plugin-cfg.xml.

6. Restart the IHS service.

Step 2 Testing the IHS load balancing configuration

Open a web browser by using the following link:

http://IHS load balancer server (MachineA)/cqweb

You should see the ClearQuest login page.

The ClearQuest Web server URL is now http://IHS load balancer server (MachineA)/cqweb