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Clustering allows eXo Platfrom users to run various portal instances on several parallel servers which are also called nodes. The load is distributed across different servers, so the portal is still accessible via other cluster nodes in case of any failed servers. Thanks to adding more nodes to the cluster, eXo Platform's performance can be much improved. A cluster is a set of nodes which is managed together and participate in the workload management. Installing eXo Platform in the cluster mode is considered in the following main cases:
Load Balancing: when a single server node is not enough for handling the load.
High Availability: if one of nodes is failed, the rest of nodes in the cluster can assume the workload of the system. It means that no access is interrupted.
These characteristics should be handled by the overall architecture of your system. The Load Balancing is typically achieved by a front server or device that distributes the request to the cluster nodes. Also, the High Availability on the data layer can be typically achieved using the native replication implemented by Relation Database Management System (RDBMS) or Shared File Systems, such as SAN and NAS.