How can I observe load balance event when I have setup FCF?

Question

Dear expert,
I have setup two nodes RAC on linux and implement FCF. HA event works fine, because after one node down, connections to failed node in OC4J connection pool were cleaned up immediately. And I can observe HA event like
FINER: eventType= 256, svcName= orclx, instName= orclx1, db Name= orclx, hostName= linuxrac1, status= down, cardinality= 0
But I cannot observe LB event, it should be received too, shouldn't it?

Answer 1

Enabling Event Notification for Connection Failures in Oracle Real Application Clusters
Event notification is enabled if the SQL_ORCLATTR_FAILOVER_CALLBACK and SQL_ORCLATTR_FAILOVER_HANDLE attributes of the SQLSetConnectAttr function are set when a connection failure occurs in an Oracle RAC Database environment. Both attributes are set using the SQLSetConnectAttr function. The symbols for the new attributes are defined in the sqora.h file. The SQL_ORCLATTR_FAILOVER_CALLBACK attribute is used to specify the address of a routine to call when a failure event takes place.
The SQL_ORCLATTR_FAILOVER_HANDLE attribute is used to specify a context handle which will be passed as one of the parameters in the callback routine. This attribute is necessary in order for the ODBC application to determine which connection the failure event is taking place on.
The function prototype for the callback routine is as follows:
void failover_callback(void *handle, SQLINTEGER fo_code)
The handle parameter is the value that was set by the SQL_ORCLATTR_FAILOVER_HANDLE attribute. Null is returned if the attribute has not been set.
The fo_code parameter identifies the failure event that is taking place. The failure events map directly to the events defined in the OCI programming interface. The list of possible events is as follows:
ODBC_FO_BEGIN
ODBC_FO_ERROR
ODBC_FO_ABORT
ODBC_FO_REAUTH
ODBC_FO_END
see Oracle® Database Oracle Clusterware and Oracle Real Application Clusters Administration and Deployment Guide
chapter 6 for an example