Collecting debugging information with strace, truss, or tusc
To properly troubleshoot certain situations, it can be useful to trace which system calls AxoSyslog performs. How this is performed depends on the platform running AxoSyslog. In general, note the following points:
When AxoSyslog is started, a supervisor process might stay in the foreground, while the actual
syslog-ngdaemon goes to the background. Always trace the background process.
Apart from the system calls, the time between two system calls can be important as well. Make sure that your tracing tool records the time information as well. For details on how to do that, refer to the manual page of your specific tool (for example,
straceon Linux, or
trusson Solaris and BSD).
Run your tracing tool in verbose mode, and if possible, set it to print long output strings, so the messages are not truncated.
strace, also record the output of
lsofto see which files are accessed.
The following are examples for tracing system calls of
syslog-ng on some platforms. The output is saved into the
/tmp/syslog-ng-trace.txt file, sufficed with the PID of the related
syslog-ng process. The path of the
syslog-ng binary may be different for your installation, as distribution-specific packages may use different paths.
strace -o /tmp/trace.txt -s256 -ff -ttT /opt/syslog-ng/sbin/syslog-ng -f /opt/syslog-ng/etc/syslog-ng.conf -Fdv
tusc -f -o /tmp/syslog-ng-trace.txt -T /opt/syslog-ng/sbin/syslog-ng
IBM AIX and Solaris:
truss -f -o /tmp/syslog-ng-trace.txt -r all -w all -u libc:: /opt/syslog-ng/sbin/syslog-ng -d -d -d
NoteTo execute these commands on an already running AxoSyslog process, use the