Testing Load balancing in Oracle RAC
Posted by Kamran Agayev A. on 14th January 2013
If you’ve installed Oracle RAC (Real Application Clusters) and want to test how Load Balancing works, you can run the following shell script and check GV$SESSION view:
#!/bin/bash
. /home/oracle/.bash_profile
for ((i=1; i <= 50 ; i++))
do
nohup sqlplus -S system/oracle@racdb<<eof &
begin
dbms_lock.sleep(10);
end;
/
eof
done
This will open 50 sessions in the background. Check GV$SESSION view before and after running this query:
SQL> select inst_id,count(*) from gv$session where username is not null group by inst_id;
INST_ID COUNT(*)
———- ———-
1 10
2 9
Run the following command from the different session:
[oracle@node1 ~] ./check_load_balancing.sh
SQL> /
INST_ID COUNT(*)
———- ———-
1 33
2 36
Wait for 10 seconds (as we’ve defined “10” seconds at DBMS_LOCK.SLEEP procedure) and run the query again :
SQL> /
INST_ID COUNT(*)
———- ———-
1 10
2 9
SQL>
From the output you can see that all new sessions were distributed between two nodes appropriately.
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