Planning to use the Internet Cluster Manager (ICM)

Plan the cluster that the Internet Cluster Manager (ICM) will service. Then plan where to run the ICM itself and how many ICMs to run.

You can add Web servers to an existing cluster, use existing servers in a cluster as Web servers, or create a cluster for Web traffic only. You plan the cluster by considering the same factors you consider when you create any HCL Domino® cluster. For example, you should consider the processing power of the servers available and how much traffic there will be in the cluster. If there is a lot of Web traffic on a server, you should consider dedicating the server to Web traffic only. You should also distribute databases in a way that balances the workload.

Consider the following factors:
  • The number of servers to include in the cluster
  • The number and placement of replicas in the cluster
  • How to distribute databases across servers
  • Whether to create a private LAN for cluster traffic
  • Where to locate the ICM

Planning the location of the ICM

You can run the ICM on a server in the cluster or on a server outside the cluster. In addition, you can run multiple ICMs to be sure that one ICM is available at all times.

You can configure the ICM in several ways. For example you can:

  • Configure a single ICM and place it outside the cluster

    Dedicate a server to the ICM alone. The server should not contain any databases or server tasks other than those required to run the server. Configuring the ICM in this way makes it more reliable because there are fewer activities performed on the server that could interfere with performance and lead to server failure.

  • Configure multiple ICMs outside the cluster

    If one ICM becomes unavailable, the other remains available so that client requests are still handled. You configure both ICMs with the same host name so that if one of the ICMs fails, the other ICM takes over without affecting users.

    The benefit of multiple ICMs is availability, not increased performance. This configuration increases performance significantly only in cases where a single ICM would be overwhelmed by client requests.

  • Configure a single ICM as part of the cluster

    You can include the ICM in the cluster by running the ICM on any server in the cluster. You should run the ICM on the most powerful server in the cluster or the server that receives the least traffic.

  • Configure multiple ICMs as part of the cluster

    To improve the availability of the ICM, you can install more than one ICM in the cluster.

  • Configure one ICM outside the cluster and one inside the cluster

    You can configure one ICM to run outside the cluster and one to run inside the cluster. If the dedicated server outside the cluster becomes unavailable, you have a backup ICM available without having to dedicate a server to the additional ICM.