WebSphere

 

Portal Express, Version 6.0
Operating systems: i5/OS, Linux, Windows

 

Plan for cluster

Before installing WebSphere Portal Express for use in a managed node or as part of a cluster, review these important guidelines and limitations.

 

Before you begin

Review the Planning for deployment for the IBM WebSphere Portal Express environment before reviewing this section for planning considerations specific to clusters.

In WebSphere Application Server, a cluster is composed of multiple identical copies of an application server. A cluster member is a single application server in the cluster. WebSphere Portal Express is installed as an enterprise application server within the WebSphere Application Server infrastructure. All of the clustering features available within the WebSphere Application Server infrastructure are also available and apply to WebSphere Portal Express. Thus, a WebSphere Portal Express cluster is simply a collection of multiple WebSphere Portal Express servers that are identically configured.

When planning for WebSphere Portal Express clusters, also take into account any cluster planning required for the WebSphere Application Server nodes.

For further information, refer to the Planning section of the information center for the version of IBM WebSphere Application Server Network Deployment product supported by the version of WebSphere Portal Express you are using.

 

Guidelines for implementing cluster environments

Cluster environments should be implemented according to the following guidelines:

  1. There are several approaches you can use to configure an external Web server in a clustered environment. The instructions provided here for installing a WebSphere Portal Express follow the approach recommended by WebSphere Application Server, which involves using the Plug-ins installation wizard to install the binary plug-in module after the cell has been set up. For a complete description of the recommended procedure for configuring an external Web server in a clustered environment, refer to the WebSphere Application Server information center:

    Before using the configureweb_server_name script during Web server configuration in a managed cell, change the timeout request period for the Simple Object Access Protocol (SOAP) client on the deployment manager machine. The default, in seconds, is 180. Edit the soap.client.props file in the was_profile_root/properties directory:

    Change the line to: com.ibm.SOAP.requestTimeout=6000

  2. The deployment manager node must be installed separately before the cells and clusters can be configured. For more information, refer to Installing WebSphere Application Server Network Deployment on Windows and Linux.

  3. WebSphere Application Server provides database session persistence and memory-to-memory replication as techniques for HTTP session failover in a clustered environment. Review the following information to determine whether you want to use one of these techniques in your cluster.

    Ensure that WebSphere Application Server plugin Version 6.0.2.17 or later is installed if you are using an IBM HTTP Server as the Web server.

  4. If you add a node to a cell or change a node's configuration after it has been federated to the deployment manager, synchronize the node's configuration. In the administrative console for the deployment manager, select System Administration > Nodes, select the node from the list, and click Full Resynchronize. This helps ensure that there is no mismatch between node and cell configuration after the synchronization is complete.

  5. i5/OS:

    : Set up a recycling procedure Portal Database with the following command. This procedure automatically removes the unused journal files: 

    CHGJRN JRN(QWPS60/QSQJRN) DLTRCV(*YES)

    QWPS60 is a default name of the WebSphere Portal Express database.

 

Limitations

The following limitations apply when implementing a WebSphere Portal Express cluster:

  1. You must install and configure WebSphere Portal Express separately on each node. In addition, there can only be one WebSphere Portal Express cluster per cell.

  2. Except for the temporary state during the initial setup of the cluster, WebSphere Portal Express is not supported when running on a managed node that is not part of a clustered environment.

    A cluster may be created which contains only one portal server, enabling a single WebSphere Portal Express server to be operational in a managed cell.

  3. Windows: There is a known limitation with many Windows operating systems that limits path names to a maximum length of 259 characters. This can be a potential problem due to the depth of the WebSphere Application Server Network Deployment directory structure, particularly when deploying applications in a cluster. To avoid problems related to excessively long paths names, consider the following recommendations when installing WebSphere Application Server Network Deployment:

    • Use a short installation path. For example, use C:\WebSphere instead of C:\Program Files\IBM\Websphere.

    • Specify short cell and node names – do not use names longer than 5 characters. For example, you might use scell instead of stonemillNode01cell.

    • The name of the WAR files must be less than approximately 21 characters. The installation program attempts to truncate or rename long names before it deploys the WAR file into the application server; however, it cannot always circumvent the path name to exceed the limit. To correct this error, modify the file name to less than 21 characters.

    • Refer to the following tech note for more information: http://www-1.ibm.com/support/docview.wss?rs=688&context=SSHRKX&q1=1254579&uid=swg21254579&loc=en_US&cs=utf-8&lang=en.

  4. In a clustered environment, it is not possible to change portal settings through the Global Settings portlet or the XML configuration interface. These changes must be made by modifying the respective properties in the WebSphere Application Server administrative console, as described in Setting configuration properties.

  5. To support search in a clustered environment, install and configure search for remote search service on an application server node that is not part of the cluster. For more information on using search in a cluster, refer to the Portal Search topic.

  6. Administrative actions for WebSphere Portal Express are immediately visible for the user who performs them. However, another user can be assured of seeing the changes only if the user logs out of WebSphere Portal Express and then logs back in. This limitation applies to both cluster and non-cluster environments.

  7. If you intend to enable security after creating the cluster by using the enable-security-ldap, enable-security-wmmur-ldap, or enable-security-wmmur-db tasks, stop all cluster members before doing so.

  8. When creating a cluster or a cluster member, do not use spaces in the cluster name or the cluster member name.

  9. i5/OS limitations: Installation in a mixed node environment is not supported in an i5/OS environment.

  10. For the deployment manager and each WebSphere Portal Express node to be in the cluster, verify that each system clock is set to within 5 minutes of the others or the addNode command will fail.

 

Related information

 

Parent topic:

Clustering and WebSphere Portal Express