Oracle listener is too slow to connect to the database after address restrictions are added

Database environment: Oracle 9i

HOST: AIX 5.3

Symptom: It is too slow to connect to the database. You can use topas to check the resource usage of the host. Everything is normal. The connection from the local database to itself will be slow as long as it is listened through listener. If you use an oracle user and use sqlplus '/as sysdba' to connect, everything works. The listener problem is found in the database. So I checked the listener log and found that the listener log was full five months ago, causing the listener process to be abnormal.

Solution: Clear the listener log and restart the listener.

This problem occurs again later, but the log is not large, and this problem occurs after a period of running. Find the reason. It is found that another IP address that is not in the address list will apply for a connection every 10 seconds, but there will be a denial in the log, but this IP address is not recorded. No way. Remove the address restriction first and restart listener. View the log, find the address, and then directly restrict it from the firewall. This problem is the final outcome.

Conclusion: After adding address restrictions to oracle, you must pay attention to the size of listening logs. Note that there cannot be IP addresses that are not in the address list for frequent access. Otherwise, the database may run for a period of time, connecting to the database will be very slow.