Some log messages are lost when the *logrotate* "copytruncate" option is used with the *rsyslog* *imfile* module
When the *logrotate* utility with "copytruncate" option is rotating a log file, the *imfile* module of the *rsyslog* utility might not have read all of the log messages from the file being rotated. As a consequence, these log messages are lost. To work around this problem, do not use the "copytruncate" log rotation option. Alternatively, it is possible to lower the probability of message loss by using the experimental option "reopenOnTruncate=on".
Description of problem:
Using the rsyslog File Input module with tomcat6's catalina.out file, it stops logging to syslog when catalina.out logrotate occurs.
/var/log/tomcat6/catalina.out {
copytruncate
weekly
rotate 52
compress
missingok
create 0644 tomcat tomcat
}
** rsyslog **
$ModLoad imfile
# catalina.out
$InputFileName /var/log/tomcat6/catalina.out
$InputFileTag catalina-out
$InputFileStateFile stat-catalina-out
$InputFileSeverity info
$InputFilePersistStateInterval 20000
$InputRunFileMonitor
Version-Release number of selected component (if applicable):
rsyslog-5.8.10-8.el6.x86_64
How reproducible:
Always
Steps to Reproduce:
1. Install tomcat6 package
2. Configure rsyslog to use the File Input module on /var/log/tomcat6/catalina.out
3. Force a logrotate
Actual results:
File input module stops working
Expected results:
File input module should continue logging to syslog
Additional info:
When logrotate occurs on most services/daemons, a reload(or SIGHUP) is sent to the process which causes it to release an association(or "connection") with the current log file and open a new file descriptor to the newly created log file. This is how logrotate works without issues for rsyslog, cron, etc.
File input module was tested with logrotate and works for httpd(which does not use copytruncate)
Actually, this is a known issue[0].
The v5 and (since el6.6) v7 versions don't support rotation of monitored files.
This functionality was added upstream "recently", but only to the v8 branch. It _might_ be possible to backport it, but that would need more research.
[0] http://lists.adiscon.net/pipermail/rsyslog/2013-June/033068.html
Looks like the issue is with the 'copytruncate' option to logrotate. In the v5 version, the imfile plugin should support proper file rotation (renaming the current file and proceeding to write to a new one with the original name).
I'm not familiar with Tomcat, but, theoretically, it should be possible to modify it (or write a script) to either do a proper rotation, or, instead of writing to catalina.out, pipe the logs to logger(1) or somesuch, or utilize some other input plugin other than imfile.
Tested this with rsyslog v8 and not able to reproduce the tomcat issue anymore (catalina still logs after forced logrotate with above configuration options)
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.
For information on the advisory, and where to find the updated
files, follow the link below.
If the solution does not work for you, open a new bug report.
https://access.redhat.com/errata/RHBA-2017:2306
Description of problem: Using the rsyslog File Input module with tomcat6's catalina.out file, it stops logging to syslog when catalina.out logrotate occurs. /var/log/tomcat6/catalina.out { copytruncate weekly rotate 52 compress missingok create 0644 tomcat tomcat } ** rsyslog ** $ModLoad imfile # catalina.out $InputFileName /var/log/tomcat6/catalina.out $InputFileTag catalina-out $InputFileStateFile stat-catalina-out $InputFileSeverity info $InputFilePersistStateInterval 20000 $InputRunFileMonitor Version-Release number of selected component (if applicable): rsyslog-5.8.10-8.el6.x86_64 How reproducible: Always Steps to Reproduce: 1. Install tomcat6 package 2. Configure rsyslog to use the File Input module on /var/log/tomcat6/catalina.out 3. Force a logrotate Actual results: File input module stops working Expected results: File input module should continue logging to syslog Additional info: When logrotate occurs on most services/daemons, a reload(or SIGHUP) is sent to the process which causes it to release an association(or "connection") with the current log file and open a new file descriptor to the newly created log file. This is how logrotate works without issues for rsyslog, cron, etc. File input module was tested with logrotate and works for httpd(which does not use copytruncate)