QClog Daemon


QClog is an application based on the SeisComP3 framework that receives QC messages and stores all station parameters in a Round Robin Database(RRD). The stored station parameters can be visualized in a user friendly way using the integrated web front-end. The front-end provides three different views: The admin, the overview and the station page. The first one controls the style of GUI. The second page gives an overview of all stations received QC messages for. The latter one shows detailed station information about common QC parameter e.g. delay, latency and offset.


  • rrdtool 1.4.2 or higher
  • Apache HTTP Server
  • mod_python - Apache/Python Integration
  • Cheetah - The Python-Powered Template Engine
  • SeisComP3 Seattle/Jakarta with scqc running


This section describes the installation of the QCLog package. The next steps assumes that SeisComP3 has been installed in the default installation directory /home/sysop/seiscomp3.

QCLog Service

  1. Run the following command to install the latest QCLog package
gsm install qclog
  1. Generate the python files from the Cheetah templates with
cd seiscomp3/share/qclog/files/
  1. Change the SeisComP3 messaging connection if necessary
  2. Enable and start the service
seiscomp enable qclog
seiscomp start qclog

QCLog web configuration

Besides the SeisComP3 configuration QCLog uses a separate configuration file named qc_config.cfg which contains several options like for instance the RRDCache path. Depending on the install environment the path to the file needs to be adapted to get QCLog running. Available options are:

Option Descritpion
RRDpicturepath [1] Path to store the generated pictures
RRDpicturepathhtml Link-path(html) for generated pictures
RRDpath Index- and rrd-file directory
config Path of this config file
RRDbinarypath Path to the binaries of qclog, for generating pictures, etc.

The QCLog package ships with an example configuration

  1. Create a new QCLog web configuration based on the example template
cd seiscomp3/share/qclog/config
cp qc_config.cfg.example qc_config.cfg
  1. Adapt the configuration if necessary

Apache web server integration

Ubuntu 18.04

  1. Open the file /etc/apache2/envvars and add the following line
export LD_LIBRARY_PATH=${LD_LIBRARY_PATH}:/home/sysop/install/seiscomp3/lib
  1. Create a new file qclog.conf with the following content in the directory /etc/apache2/sites-available
Alias /qclog /var/www/qclog/
<Location ~ "/qclog/(stream|admin|overview)">
    PythonPath "['/home/sysop/install/seiscomp3/share/qclog/files/python',
                 '/home/sysop/install/seiscomp3/lib/python/seiscomp3'] + sys.path"
    SetHandler mod_python
    PythonHandler qc_handler
    PythonDebug On
PythonEnablePdb On

<Directory "/var/www/qclog">
    DirectoryIndex qclog.html
  1. Enable the site and the mod python extension with
a2ensite qclog.conf
a2enmod python
  1. Restart the Apache web server
service apache2 restart


The QCLog overview page will not be generated automatically by the service. One option to trigger the creation of the page is a crontab entry.

  1. Open the cron tab editor
crontab -e
  1. To update the overview page every five minutes add the following line
*/5 * * * * cd $SC3_INSTALL_DIR/share/qclog/files/python/ && $SC3_INSTALL_DIR/bin/seiscomp exec python qc_index.py > ../html/qclog.html
  1. Save the changes
[1]The directory must exist and the www-data user needs write access to the specified directory.



qclog inherits global options.


-h, --help

show a help message and exit


set for the old Qcmessage


load the stations out of the inventory and create all rrd’s and index-files(Overwrite old rrd’s) Default:write the rrd- and index-files on the fly