$vi conn.sh
sqlplus sys/[email protected]:1521/orcl as sysdba
select * from v$version;
exit;

$vi conn1.sh
sqlplus sys/[email protected]:1521/orcl1 as sysdba
select * from v$version;
exit;

$vi conn2.sh
sqlplus sys/[email protected]:1521/orcl2 as sysdba
select * from v$version;
exit;

$vi connect.sh
for i in {1..200000}
do
for j in {1..40}
do
sh /home/oracle/conn.sh
done
done
EOF

$vi connect1.sh
for i in {1.. 200000}
do
for j in {1. .40}
do
sh /home/oracle/conn1.sh
done
done
EOF
…
$vi connect2.sh
for i in {1.. 200000}
do
for j in {1. .40}
do
sh /home/oracle/conn2.sh
done
done
EOF
…

nohup sh connect.sh > /dev/null 2>&1&
nohup sh connect1.sh > /dev/null 2>&1&
nohup sh connect2.sh > /dev/null 2>&1&

[oracle@orcl:/u01/app/oracle/diag/tnslsnr/orcl/listener/trace]$ tail -20f listener.log

$grep 18-FEB-2022  listener.log | sed s/*.*SERVICE_NAME=/ /g;s/).*HOST=/ /g;s/).*$//g   | awk 
{if(NF==4){print "insert into t_tab 
values("$1","$2","$3","$4");"}}   > 
/home/oracle/insert.sql

Create table t_tab( a1 varchar2(50),a2  varchar2(50),a3  varchar2(50),a4  varchar2(50));
@/home/oracle/insert.sql

select  a1,substr(a2,1,5),a3,count(1) from t_tab where a3 in (orcl,orcl1,orcl2) group by a1,substr(a2,1,5),a3 order by count(1) desc;