Fast Application Notification: new whitepaper
Fast Application Notification (FAN) is a critical component towards solving the poor experience that end users can encounter when planned maintenance, unplanned outages, and load imbalances occur that make Oracle database instances unavailable or unresponsive. FAN enables end-to-end, lights-out recovery of applications and load balancing at runtime based on real transaction performance.
With FAN, the continuous service and continuous connections built into Oracle Real Application Clusters and Oracle Data Guard are extended to applications and application servers. When the state of database services change (to up, down, or unresponsive), the new status is posted to interested subscribers through FAN events. FAN provides rapid notification about state changes for database services, instances, the databases themselves, and the nodes that form the cluster, and starting with Oracle Database 12c with Global Data Services (distributed database systems).
Oracle drivers and Oracle pools use FAN events to achieve the following:
- Draining of work during planned maintenance with no errors whatsoever returned to applications,
- Very fast detection of failures so that recovery of applications can occur in real time
- Load balancing of incoming work at runtime when performance imbalances occur and also following instances leaving and joining the system and resources becoming available.
- Affinity advice for incoming work so that related conversations, for example successive web sessions, are routed together for best performance.
The white paper:
- Outlines the benefits of enabling FAN events for your database system
- Dissects the FAN events and their published fields
- Describes how to view FAN events using FANwatcher
- Steps through how to integrate and enable FAN events for Oracle and non-Oracle applications
The target audience includes RAC database administrators, Data Guard database administrators, and application integrators who need rapid notification of planned maintenance and unplanned outages integrated with their applications or application servers, monitoring consoles or internal business workflow systems.