请问各位专家，本人遇到内存溢出导致实例挂掉的情况，有什么好的排查思路呢？
/var/log/messages:
Mar 22 17:15:13 his1rac1 kernel: [94798639.040573] Out of memory: Kill process 133843 (oracle) score 150 or sacrifice child
Mar 22 17:15:13 his1rac1 kernel: [94798639.040578] Killed process 133843 (oracle) total-vm:320268996kB, anon-rss:188724kB, file-rss:79413580kB
Mar 22 17:15:28 his1rac1 kernel: [94798662.376866] sched: RT throttling activated

alert.log:
Mon Mar 22 17:15:14 2021
System state dump requested by (instance=1, osid=133385 (PMON)), summary=[abnormal instance termination].
System State dumped to trace file /oracle/11.2.0/db/diag/rdbms/his1db/主机名/trace/主机名_diag_133788_20210322171514.trc
Mon Mar 22 17:15:15 2021

Fatal NI connect error 12537, connecting to:
(LOCAL=NO)

VERSION INFORMATION:
TNS for Linux: Version 11.2.0.4.0 - Production
Oracle Bequeath NT Protocol Adapter for Linux: Version 11.2.0.4.0 - Production
TCP/IP NT Protocol Adapter for Linux: Version 11.2.0.4.0 - Production
Time: 22-MAR-2021 17:15:15
Tracing not turned on.
Tns error struct:
ns main err code: 12537

TNS-12537: TNS:connection closed
ns secondary err code: 12560
nt main err code: 0
nt secondary err code: 0
nt OS err code: 0
opiodr aborting process unknown ospid (235294) as a result of ORA-609
Mon Mar 22 17:15:16 2021
PMON (ospid: 133385): terminating the instance due to error 484

Mon Mar 22 17:15:28 2021
Termination issued to instance processes. Waiting for the processes to exit
Instance terminated by PMON, pid = 133385
USER (ospid: 235511): terminating the instance
Instance terminated by USER, pid = 235511