Load Balancing Advisory FAN Events

The load balancing advisory FAN events provide metrics for load balancing algorithms. The easiest way to take advantage of these events is to use the run-time connection load balancing feature of an Oracle integrated client such as JDBC, Universal Connection Pool (or the deprecated Implicit Connection Cache), ODP.NET Connection Pools, OCI session pools, or Oracle WebLogic Server Active GridLink for Oracle RAC. Other client applications can take advantage of FAN programatically by using the Oracle RAC FAN API to subscribe to FAN events and execute event-handling actions upon receipt. Table 5-4 describes the load balancing advisory FAN event parameters.

See Also:

Oracle Database JDBC Developer's Guide for more information about the Oracle RAC FAN API

Table 5-4 Load Balancing Advisory FAN Events

Parameter	Description
VERSION	Version of the event record. Used to identify release changes.
EVENT_TYPE	A load balancing advisory event is always of the `SERVICEMETRICS` event type.
SERVICE	The service name; matches the value of `NAME` in `DBA_SERVICES`.
DATABASE	The unique database supporting the service; matches the initialization parameter value for `DB_UNIQUE_NAME`, which defaults to the value of the initialization parameter `DB_NAME`.
INSTANCE	The name of the instance that supports the service; matches the `ORACLE_SID` value.
PERCENT	The percentage of work requests to send to this database instance.
FLAG	Indication of the service quality relative to the service goal. Valid values are `GOOD`, `VIOLATING`, `NO DATA`, and `BLOCKED`.
TIMESTAMP	The local time zone to use when ordering notification events.

Note:

The INSTANCE, PERCENT, and FLAG event parameters are generated for each instance offering the service. Each set of instance data is enclosed within braces ({}).