By default, APM Server sends all its output to syslog. When you run APM Server in the foreground, you can use the -e command line flag to redirect the output to standard error instead. For example:

apm-server -e

The default configuration file is apm-server.yml (the location of the file varies by platform). You can use a different configuration file by specifying the -c flag. For example:

apm-server -e -c myapm-serverconfig.yml

You can increase the verbosity of debug messages by enabling one or more debug selectors. For example, to view the published transactions, you can start APM Server with the publish selector like this:

apm-server -e -d "publish"

If you want all the debugging output (fair warning, it’s quite a lot), you can use *, like this:

apm-server -e -d "*"