use Log::Log4perl qw(:easy);

Log::Log4perl->init(\ qq{
    log4perl.logger=DEBUG, A1
    log4perl.appender.A1          = Log::Log4perl::Appender::File
    log4perl.appender.A1.filename = test2.log
    log4perl.appender.A1.syswrite = 1
    log4perl.appender.A1.layout   = SimpleLayout
});

my $id = shift;

for (1..20) {
    DEBUG "tick $_ from $id";
    sleep(1);
}

##</code><code>##

perl -E "say for 1..10" | xargs -n 1 -P 10 perl log_test.pl

##</code><code>##

...
DEBUG - tick 1 from 4
DEBUG - tick 1 from 5
DEBUG - tick 2 from 9
DEBUG - tick 2 from 10
...