Integration Server 10.3 | Clustering Guide | An Overview of Clustering | What Data Is Shared in a Cluster?
 
What Data Is Shared in a Cluster?
Data storage depends on whether the cluster is stateful or stateless.
In both types of clusters, Integration Server stores data from cluster nodes (for example, service results, scheduled tasks, audit data, and documents) in shared database components. For information about database components, see Installing Software AG Products.
In a stateful cluster, the session state for clients connected to cluster nodes is stored in a distributed cache in a Terracotta Server Array. The cache makes state available to all servers in the cluster, which enables multi-step transactions in a conversation to begin on one node in the cluster and continue on other nodes. For example, in the Cross-site Request Forgery (CSRF) Guard feature, a token is created locally on a server and saved in the distributed Terracotta Server Array cache, which makes the token available to all other cluster nodes.
In a stateless cluster, and the session state of a client is not stored in a distributed Terracotta Server Array cache; state is only available locally. Stateless clusters do not support all Integration Server-related features and components (see table below). Stateless clusters require less hardware and less software, and less work is needed for set up and maintenance. However, stateless cluster cannot support multi-step transactions on multiple cluster nodes because state is not available.
Integration Server Component or Feature
Supported by Stateless Cluster?
Cross-site request forgery (CSRF) Guard
No
Exactly once for document history
Yes
Failover support
No
File polling
Yes
Guaranteed delivery
Yes
OAuth authorization server
No
OpenID Connect
No
Scheduler
Yes, target node of Any or a specific server; all option not supported
Service results caching
Yes
Business Rules
Yes
CloudStreams
Yes
Dynamic Business Orchestrator
No
Process Engine and Monitor operation
Yes
Interaction between Process Engine and Trading Networks
Yes
Trading Networks
Yes
Adapters, including notifications produced by Integration Server scheduler services
Yes
1SYNC, AS4, ebXML, EDI, EDIINT, SWIFT eStandards Modules
Yes
Chem, FIX, HIPAA, Papinet, Rosettanet eStandards Modules
No