Log::Log4perl::Appender::RRDs - Log to a RRDtool Archive


    use Log::Log4perl qw(get_logger);
    use RRDs;
    my $DB = "myrrddb.dat";
      $DB, "--step=1",
    print time(), "\n";
      log4perl.category = INFO, RRDapp
      log4perl.appender.RRDapp = Log::Log4perl::Appender::RRDs
      log4perl.appender.RRDapp.dbname = $DB
      log4perl.appender.RRDapp.layout = Log::Log4perl::Layout::PatternLayout
      log4perl.appender.RRDapp.layout.ConversionPattern = N:%m
    my $logger = get_logger();
    for(10, 15, 20, 25) {
        sleep 1;


Log::Log4perl::Appender::RRDs appenders facilitate writing data to RRDtool round-robin archives via Log4perl. For documentation on RRD and its Perl interface RRDs (which comes with the distribution), check out

Messages sent to Log4perl's RRDs appender are expected to be numerical values (ints or floats), which then are used to run a rrdtool update command on an existing round-robin database. The name of this database needs to be set in the appender's dbname configuration parameter.

If there's more parameters you wish to pass to the update method, use the rrdupd_params configuration parameter:

    log4perl.appender.RRDapp.rrdupd_params = --template=in:out

To read out the round robin database later on, use rrdtool fetch or rrdtool graph for graphic displays.


Copyright 2002-2013 by Mike Schilli <> and Kevin Goess <>.

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.


Please contribute patches to the project on Github:

Send bug reports or requests for enhancements to the authors via our

MAILING LIST (questions, bug reports, suggestions/patches):

Authors (please contact them via the list above, not directly): Mike Schilli <>, Kevin Goess <>

Contributors (in alphabetical order): Ateeq Altaf, Cory Bennett, Jens Berthold, Jeremy Bopp, Hutton Davidson, Chris R. Donnelly, Matisse Enzer, Hugh Esco, Anthony Foiani, James FitzGibbon, Carl Franks, Dennis Gregorovic, Andy Grundman, Paul Harrington, Alexander Hartmaier David Hull, Robert Jacobson, Jason Kohles, Jeff Macdonald, Markus Peter, Brett Rann, Peter Rabbitson, Erik Selberg, Aaron Straup Cope, Lars Thegler, David Viner, Mac Yang.