WebLogic clustering offers three important benefits:
The capacity of an application deployed on a WebLogic Server cluster can be increased dynamically to meet demand. You can add server instances to a cluster without interruption of service — the application continues to run without impact to clients and end users.
2. Load balancing:
The ability to distribute requests across all members of the cluster, according tothe workload on each server.
3. High availability:
A mix of features that ensure applications and services are available even if aserver or machine fails. Clients can continue to work with little or no disruption ina highly available environment. WebLogic achieves high availability using acombination of features: replication, failover, and migratable services.