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Cluster considerations

Multiple portal servers can be clustered with IBM WebSphere Application Server Network Deployment.

HCL Digital Experience comes standard with WebSphere® Application Server Network Deployment. The Server Network Deployment element is a distribution of IBM® WebSphere Application Server that provides a Deployment Manager server type for centrally managing and clustering a series of servers. A clustered series of portal servers means that all portal instances share configuration, including database, applications, portlets, and site design. The cluster provides a domain against which most administrative actions are completed once and synchronized with each server in the cluster. This action both simplifies administration and ensures that all cluster members are configured and behave identically.

A server cluster also provides a shared domain in which session and cache data can be replicated and kept consistent on all members of the cluster. The cluster also provides an application synchronization mechanism that ensures consistent application management (start, stop, updates, and so on) in the cluster.

WebSphere Application Server provides an HTTP Server plug-in that can balance user traffic across all members of the cluster. And a feature called "session affinity" ensures that a user remains bound to a specific cluster instance during their session to improve efficiency and performance. Additionally, in the event a cluster member is down the workload management features of the plug-in recognizes that the instance is no longer available and routes traffic around it.

There are two types of clusters: vertical and horizontal clusters. Most large-scale deployments are mixtures of both cluster types.

It is also possible to deploy multiple portal clusters to improve availability, failover, and disaster recovery.

For best results, review the cluster guidelines and limitations topics for more information about what is involved in setting up a cluster.

Restriction

The serverName parameter is hardcoded to HCL Portal. The serverName parameter cannot be changed in a stand-alone environment. If you do change it, the ConfigEngine scripts do not work. For a clustered environment, see Virtual Member Manager integration for options on replacing the HCL Portal JVM.

  • Guidelines for setting up a cluster
    When you set up an HCL Portal cluster, you must consider all planning that is required for the WebSphere Application Server nodes.
  • Limitations for setting up a cluster
    Certain limitations apply when you set up an HCL Portal cluster.
  • HTTP session failover
    View the global settings portlet to verify which server is handling user requests for a session.
  • Security options
    Security is enabled by default for the WebSphere Application Server deployment manager.
  • Security scenarios
    Setting up a clustered environment requires that you consider the following two security scenarios.
  • Using external security managers in a cluster Complete the configuration for an external security manager after you have completed all other setup tasks.
  • Planning for multiple clusters
    Multiple clusters are sets of servers that are managed together in a single administrative domain (or cell) and participate in workload management.
  • Dynamic clusters
    You can create a dynamic cluster to run HCL Portal.
  • Cluster maintenance
    Maintaining an HCL Portal in a cluster typically means applying corrective services (fix packs and interim fixes) or updating the software release level on each node in the cluster.