Optimize Distributed Workload - Expert Oracle RAC Performance Diagnostics and Tuning - page 506

How Do You Verify Whether the RCLB Feature Is Working?
When MMON generates load advices, it is stored in GV$SERVICEMETRIC view and is used to communicate with the
client of the current load. For example, the following query displays the load characteristics as updated by MMON
in GV$SERVICEMETRIC view. The view is joined with GV$INSTANCE and GV$ACTIVE_SERVICES to obtain additional
information:
set pagesize 60 space 2 numwidth 8 linesize 132 verify off feedback off
column SERVICE_NAME format a20 truncated heading 'Service'
column INSTANCE_NAME heading 'Instance' format a10
column SERVICE_TIME heading 'Service Time|mSec/Call' format 999999999
column CPU_TIME heading 'CPU Time |mSec/Call' 99999999
column DB_TIME heading 'DB Time |mSec/Call' 99999999
column THROUGHPUT heading 'Calls/sec' format 99.99 break on SERVICE_NAME skip 1
SELECT SERVICE_NAME,
INSTANCE_NAME,
ELAPSEDPERCALL SERVICE_TIME,
CPUPERCALL CPU_TIME,
DBTIMEPERCALL DB_TIME,
CALLSPERSEC THROUGHPUT
FROM GV$INSTANCE GVI,
GV$ACTIVE_SERVICES GVAS,
GV$SERVICEMETRIC GVSM
WHERE GVAS.INST_ID = GVSM.INST_ID
AND GVAS.NAME_HASH = GVSM.SERVICE_NAME_HASH
AND GVI.INST_ID = GVSM.INST_ID
AND GVSM.GROUP_ID = 10
ORDER BY
SERVICE_NAME,
GVI.INST_ID;
Service Time
Elapsed CPU Time DB Time
Service Instance mSec/Call mSec/Call mSec/Call Calls/sec
---------- ---------- ------------ ---------- ---------- ---------
TAPS SCDB_1 1360 329 1360 232.07
SCDB_2 1444 385 1444 222.71
SCDB_3 1918 240 1918 161.55
SCDB_4 736 254 736 678.04
SCDB_5 2292 772 2292 27.09
FIPS SCDB_2 60317 23490 60317 79.88
SCDB_3 46358 12926 46358 105.18
SCDB_4 52800 13701 52800 44.31
SCDB_5 54303 13607 54303 71.31
In the preceding output, service TAPS on both instances does not seem balanced. The service time on SCDB_2
is high, the overall throughput is low; however, the DB time and CPU time values seem lower. When a message is
received by the application server using the FAN technology regarding the current state of the instance, new sessions
will be directed by FAN to instance SCDB_2 .