Weird TNS-12531 and ORA-25253 errors

Database environment

Operating system: windows 2008R2

Database version: oracle 11.2.0.4

Fault description

After the database listening service starts for a while, it remains stuttered when checking the listening status. Check the listening log report TNS-12531, and the alarm log report ORA-25253; screenshot is as follows:

Eliminate the wrong train of thought

(1) first, check that the listening configuration of the database is correct, and the size of the listening log is normal.

(2) the network is normal and stable, including IP and DNS.

(3) try to rebuild the monitoring service. Both dynamic and static monitoring have been tried, but the problem still occurs.

(4) check the memory allocation of the database. PGA has 4G. In fact, 4G must meet the conditions.

(5) finally, I searched the MOS community, and someone mentioned that there may be too many APP processes under the server, resulting in abnormal listening service. I looked at the task manager and found that there were nearly 400 processes, among which there were many duplicate processes, such as expdp.exe, cmd.exe, etc., which were obviously problematic. It seems that the problem is likely to be here.

Solution

After communicating with the site personnel, the server has not been restarted for a long time, after confirmation, the server is restarted, and then the total number of processes is reduced to 100; the monitoring stutter problem is solved.

For the first time, you have encountered a monitoring exception due to a large number of processes because the server has not been restarted for a long time. Record it here.