Truncating, Rotating, Flushing Listener.log file

Listener Log file audits trail information which enables us to analyze network statistics, client connection requests, service registration events or other stuff. So it is obvious that listener log can contain very useful information for troubleshooting network related problems.

This file is usually small and easy to diagnose but in cases of very active databases it could grew very fast to several gigabytes. We have listener.log file which is growing very fast because of very active OLTP database. After few months that file grew up to 4 GB and there stopped updating new logs.

I asked on OTN forums why it stopped on 4 GB's and here is the link to that question:
http://forums.oracle.com/forums/thread.jspa?threadID=921004&tstart=0

In this post I want to show you how to truncate listener log file and free some disk space doing that.

You could stop listener service process, move or remove listener.log file and start service again. But what if your Oracle database is running 24/7 and you cannot easily stop listener service. Then you cannot truncate listener.log file using mv or rm commands because Oracle will continue writing to that file and will not free up disk space.


First solution:




You could also use [ $echo "" > listener.log ] to truncate file.


Second solution - using LSNRCTL utility:





Oracle 11g introduced new diagnostically system - "Automatic Diagnostic Repository (ADR)" and now we have listener log written to xml file (besides listener.log file).
Trying to change log file using LSNRCTL utility will fail with:

TNS-01251: Cannot set trace/log directory under ADR.

LSRNCTL>set current_listener
LSNRCTL>set log_directory fails:

TNS-01251: Cannot set trace/log directory under ADR

For solution find more information on Metalink - note 762787.1.


Third solution - using LOGROTATE command:

We can use logrotate command in cron to rotate listener logs in some time intervals. Logrotate is designed to help administrators with managing large numbers of log files. It allows automatic rotation, compression, removal, and mailing of log files.

Simple logrotate configuration:

Add file:
/etc/logrotate.d/oracle

- write this lines into that file:

/oracle/product/10.2.0/network/log/listener.log {
missingok
weekly
rotate 4
compress
create 644 oracle dba
}

Logs will rotate every weak and old ones will be compressed. We will have 4 latest backups.


Fourth solution - using LSNRCTL utility #2

Oracle TNS listener holds an open handle to listener.log file so I can't just rename file because Oracle won't create new log file for logging purposes. To recreate log file I must restart TNS listener process. Better option is to disable logging to release open handle, rename file and enable logging.





Fifth solution - custom script:

trunc_lsnr.sh




Execute this script as a cron job in time intervals based on your needs.