Clustering extends the reliability, availability, and scalability of Integration Server and accomplishes this by providing the infrastructure and tools to use multiple Integration Servers as if they were a single virtual server.

CloudStreams supports the use of clustering by either distributing the processing load for streaming API events across Integration Server instances or limiting the processing to a single Integration Server node, while guaranteeing processing in each mode exactly once.

Apart from the infrastructure requirements enforced by Integration Server to operate in a clustered mode, CloudStreams leverages the distributed cache, which stores data in a Terracotta Server Array to coordinate processing of events between different Integration Server instances. See the webMethods Integration Server Clustering Guide for more information on clustering.