Configuring load balancing for ClearCase Remote Client (CCRC) by using Change Management (CM Server)/CCRC WAN Server and IBM HTTP Server (IHS)

This tech note describes how to configure load balancing for CCRC version 7.1.0.2 or later by using two CM / CCRC WAN Servers and IHS.

NOTE : CM Server is referred to as CCRC WAN Server starting with v8.0.


Configuration:

• 2 CM / CCRC WAN Servers with ClearCase and/or ClearQuest installed
• 1 IHS load balancer with ClearCase and/or ClearQuest installed
• Optional: 1 CCRC view storage server (ClearCase only)

The following sample configuration scenario is used in the examples in this tech note:

Machine	ClearCase	CM/CCRC WAN Server	IHS	ClearQuest	Usage
A	Yes	Yes	Yes	Optional	CCRC Server, Load balancer
B	Yes	Yes	No(*1)	Optional	CCRC Server
C (*2)	Yes ?? No (*2)	No	No	No	Optional view storage

(*1) In ClearCase 7.1.0.2, 7.1.1.x, 7.1.2.x, IHS is installed with the CM Server. IHS must be disabled. In ClearCase 8.0.0.x, IHS need not be installed on this machine.

(*2) Storage devices such as NetApp can be used for shared view storage.

Perform the following tasks to configure load balancing:

1. Configure the CCRC view storage location
2. Configure the CM / CCRC WAN Servers and IHS
3. Test the IHS load balancing configuration

I. Configure the CCRC view storage location

All CM / CCRC WAN Servers that participate in a load balanced configuration must use the same view storage location. The shared view storage location can reside either on a CM / CCRC WAN Server machine in the configuration or on a dedicated view storage server. Network storage devices may also be used for view storage.

Server configuration parameters.

• In ClearCase 7.1.x.x:
  MBEANs configuration attributes are used to configure the CM Server. Note that the information in tech note 1384772 supersedes the Information Center topic "Setting available MBEAN attributes": https://publib.boulder.ibm.com/infocenter/cchelp/v7r1m0/topic/com.ibm.rational.clearcase.cc_admin.doc/topics/cm_server/admin_console.htm
• In ClearCase 8.0.0.x:
  Server configuration parameters are specified in <CC_HOME>/config/ccrc/server.conf. e.g.
  
  [Windows] c:\Program Files\IBM\RationalSDLC\Clearcase\config\ccrc\server.conf
  [UNIX/Linux]/opt/rational/clearcase/config/ccrc/server.conf.
  
  Refer to Product Documentation for "General configuration of the CCRC WAN Server".
  

Steps to configure shared view storage:

a. Create a path to a network storage location. You will use this path to set the ccrcViewStorage configuration parameter in the next step.

• In ClearCase version 7.1.0.2:
  The network path that you choose must exist prior to setting the ccrcViewStorage MBEAN parameter and must be fully accessible to the account in which CM Server is installed.
  
• In ClearCase version 7.1.1 and 7.1.2:
  The network path that you choose should exist prior to setting the ccrcViewStorage MBEAN parameter and should be fully accessible to the account in which CM Server is installed. Setting this attribute will not fail if these constraints are not met. However, the CM Server behavior might be unpredictable if the path that you specify does not exist or is not accessible to the account in which CM Server is installed.
  
• In ClearCase version 8.0:
  The network path specified by ccrcViewStorage must be fully accessible by CCRC users accessing this server.

b. On each CM / CCRC WAN Server, set the configuration parameter ccrcViewStorage to the network path that created above and set the configuration parameter ccrcUseViewHostPathForGlobalPath to true:

• In ClearCase 7.1.0.2, 7.1.1.x and 7.1.2.x:
  • To set the MBEAN parameters on a UNIX system or Linux host, use the wsadmin.sh script. For example:
  
  # cd /opt/rational/common/CM/scripts
  # setenv WAS_BIN /opt/rational/common/eWAS/bin /* For a csh shell */
  # $WAS_BIN/wsadmin.sh
  wsadmin> source teamAdminUtils.jacl
  wsadmin> set t [getTeamServer]
  wsadmin> $AdminControl getAttributes $t
  wsadmin> $AdminControl setAttribute $t ccrcViewStorage /net/MachineC/viewstorage/ccrc
  wsadmin> $AdminControl setAttribute $t ccrcUseViewHostPathForGlobalPath true
  wsadmin> $AdminControl getAttributes $t /* Verify the changes */
  wsadmin> exit
  
  • To set the MBEAN parameters on a Windows host, use the wsadmin.bat script. For example:
    
    
    # cd "C:\Program Files\IBM\RationalSDLC\common\CM\profiles\cmprofile\scripts"
    # "C:\Program Files\IBM\RationalSDLC\common\eWAS\bin\wsadmin.bat"
    wsadmin> source teamAdminUtils.jacl
    wsadmin> set t [getTeamServer]
    wsadmin> $AdminControl getAttributes $t
    wsadmin> $AdminControl setAttribute $t ccrcViewStorage //MachineC/viewstorage/ccrc
    wsadmin> $AdminControl setAttribute $t ccrcUseViewHostPathForGlobalPath true
    wsadmin> $AdminControl getAttributes $t /* Verify the changes */
    wsadmin> exit
    

• In ClearCase 8.0.0.x:
  Specify the configuration parameters in <CC_HOME>/config/ccrc/server.conf. e.g.
  
  [Windows] c:\Program Files\IBM\RationalSDLC\Clearcase\config\ccrc\server.conf
  [UNIX/Linux]/opt/rational/clearcase/config/ccrc/server.conf.
  
  Refer to Product Documentation for "General configuration of the CCRC WAN Server".

II. Configure the CM / CCRC WAN Servers and IHS

Perform the following steps to configure the CM / CCRC WAN Servers and IHS:

1. Modify the file server.xml on each CM / CCRC WAN Server in the configuration. In our example, this is MachineA and MachineB.

a. Open the file server.xml in a text editor. Here is the default path to server.xml:

• On the UNIX system and Linux:
In ClearCase version 7.1.0.2, 7.1.1.x, 7.1.2.x:
/opt/rational/common/CM/profiles/cmprofile/config/cells/dfltCell/nodes/dfltNode/servers/server1
In ClearCase version 8.0.0.x:
The CCRC WAN Server profile path is configurable during product installation. The default location for a new profile is

/opt/rational/common/ccrcprofile/config/cells/dfltCell/nodes/dfltNode/servers/server1

Adjust above path based on location of WAS profile hosting the CCRC WAN Server.

• On Windows:
In ClearCase version 7.1.0.2:
C:\Program Files\IBM\RationalSDLC\common\CM\profiles\cmprofile\config\cells\<hostname>CMProfileNode01Cell\nodes\<hostname>CMProfileNode01\servers\server1

In ClearCase version 7.1.1.x and 7.1.2.x:
C:\Program Files\IBM\RationalSDLC\common\CM\profiles\cmprofile\config\cells\dfltCell\nodes\dfltNode\servers\server1
In ClearCase version 8.0.0.x:
The CCRC WAN Server profile path is configurable during product installation. The default location for a new profile is

C:\Program Files\IBM\RationalSDLC\common\ccrcprofile\config\cells\dfltCell\nodes\dfltNode\servers\server1
Adjust above path based on location of WAS profile hosting the CCRC WAN Server.


b. Locate the components element in the WebContainer section e.g.:

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

c. Add the following properties in the components elemen e.g. t:

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

where:

• The numeric portion (1225386837920 in our example) of the xmi:id must match the numeric portion of the xmi:id values in the WebContainer section.
• 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 later use. In our example, we set value to the last two nodes of the IP address.

d. Save and close the server.xml file.

e. Optional for 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.

f. Restart the CM / CCRC WAN Server host, or restart the CM / CCRC WAN Server service by using the start and stop scripts.

2. Modify the file plugin-cfg.xml on the IHS server (MachineA in our example):

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

In ClearCase 7.1.0.2, 7.1.1.x, 7.1.2.x:
Here is the default path to plugin-cfg.xml:

• On the UNIX system and Linux:
  
  /opt/rational/common/eWAS/profiles
  
• On Windows:
  
  C:\Program Files\IBM\RationalSDLC\common\eWAS\profiles

In ClearCase 8.0.0.x:
Locate the path name of the plugin-cfg.xml in <IHS_home>/conf/httpd.conf, where IHS_home is the install location of the IBM HTTP Server. Look for an entry resembling the following:

WebSpherePluginConfig "C:\Program Files (x86)\IBM\WebSphere\Plugins\config\webserver1\plugin-cfg.xml"

b. Locate the ServerCluster section in the server.xml file:

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

In ClearCase 8.0.0.x :
The cluster name and the port number are based on the CCRC WAN server profile's configuration as specified during product installation. Default profile name is "ccrcprofile" and default port number is "16080".

c. Replace the ServerCluster section 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 WebContainer section of the server.xml file) as described in the previous section.
• The Hostname values MUST match the host names of the CM Servers. Modify the number of server entries to match the number of application servers in your load balancing configuration.

In ClearCase 8.0.0.x :
The cluster name and the port number are based on the CCRC WAN server profile. Default profile name is "ccrcprofile" and default port number is "16080".

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

e. Restart the IHS service.

III. Testing the IHS load balancing configuration
Open a Web browser and enter the following URL:

In ClearCase 7.1.0.2, 7.1.1.x, 7.1.2.x:
http:// I HS-load-balancer-server/TeamWeb/services/Team

In ClearCase 8.0.0.x:
http:// IHS-load-balancer-server/ccrc

where IHS-load-balancer-server is the IHS load balancer system. In our example, this is MachineA.

A message similar to this should appear:

In ClearCase 7.1.0.2, 7.1.1.x, 7.1.2.x:
"Hi there, this is a web service !"

In ClearCase 8.0.0.x:
"IBM Rational CCRC WAN Server"

CCRC access is through the load balancer when you use the above mentioned URL.