In a clustered configuration, the session state for clients connected to all servers in the cluster is stored in the distributed cache created by the caching software. Integration Server uses Terracotta Server Array as the caching software. The cache allows transactions in a conversation to be continued on other servers in the cluster.

Information about scheduled jobs, jobs tracked by guaranteed delivery, and XREF data is stored in an external database, identified by the ISInternal functional alias. In addition, JOIN documents (ANDs and XORs only) and the processing state of activations that are participating in a JOIN are also stored in the database. For more information about functional aliases, refer to Installing Software AG Products.