Installing Graphite for use with NAV on Debian
This is a short how-to guide for installing and configuring a simple Graphite
installation, dedicated to NAV, on a Debian 9 (Stretch) server.
Warning
Do not start NAV until you have properly configured your
carbon-cache’s storage schemas with NAV’s provided storage schema
config, or you will have issues with blank areas in your
graphs, which you will need to resolve
manually after-the-fact.
Getting Graphite
A full Graphite setup consists of the Carbon backend server, which receives
metrics over TCP or UDP, and a Graphite web frontend, which enables browsing
and retrievial/rendering of the stored metrics. NAV will collect metrics and
send to the former, while utilizing the latter to retrieve metrics and render
graphs.
Assuming you will be running Graphite on the same Debian server as you are
running NAV, all you need to do to install Graphite is:
apt-get install python-psycopg2 graphite-carbon \
python-whisper/stretch-backports graphite-web/stretch-backports
Configuring Carbon
Carbon, the metric-receiving backend of Graphite, must be configured before it
can be used with NAV. We will only be covering the simple case of using a
single carbon-cache process. Most of this information is adapted from the
Integrating Graphite with NAV section of the generic installation
documentation.
Edit /etc/carbon/carbon.conf to ensure these options are set in the
[cache] section:
MAX_CREATES_PER_MINUTE = inf
ENABLE_UDP_LISTENER = True
The first line ensures that Carbon will not delay creating Whisper backend
files for the metrics NAV sends it. The default setting is a maximum of 50
creates per minute (the setting exists to limit I/O strain on huge setups),
which means that when bootstrapping a NAV installation, hours to days can pass
before all its metrics are being actually stored in Graphite.
The second line ensures that Carbon accepts metrics on a UDP socket, which is
required by NAV.
Carbon also needs to know the resolution at which to store your time-series
data, for how long to store it, and how to roll up data from high resolution
data archives to lower resolution archives. These are the storage schemas and
aggregation methods. NAV provides its own config examples for this; on a
Graphite backend dedicated to NAV, you can simply symlink these config files
from NAV:
cd /etc/carbon/
mv storage-schemas.conf storage-schemas.conf.bak
mv storage-aggregation.conf storage-aggregation.conf.bak
ln -s /etc/nav/graphite/*.conf /etc/carbon/
Finally, restart the carbon-cache daemon:
systemctl restart carbon-cache
Configuring the Graphite web interface
To enable the web interface, you need to do two things:
- Configure and create the database it will use for storing graph definitions.
- Configure Apache to serve the web interface.
Creating the graphite database
Graphite will by default use a SQLite database, but this is not recommended in
a production setting, as it will cause issues with multiple simultaneous
users. You already have a PostgreSQL installation because of NAV, so we
recommend using this.
Make a graphite PostgreSQL user and give it a password (make note of the
password), then create a database owned by that user:
sudo -u postgres createuser --pwprompt --no-createrole --no-superuser --no-createdb --login graphite
sudo -u postgres createdb --owner=graphite graphite
The Graphite web app’s configuration file is located in
/etc/graphite/local_settings.py. There are mainly three settings you
will need to adjust: SECRET_KEY, TIME_ZONE and DATABASES. The
SECRET_KEY is used for cryptographic purposes when working with cookies and
session data (just as the SECRET_KEY setting from nav.conf). It
should be a random string of characters; we can suggest using the
makepasswd command to generate such a string:
$ makepasswd --chars 51
iLNScMiUpNy5hditWAp9e2dyHGTFoX44UKsbhj91f9xL4fdJSDY
Then edit /etc/graphite/local_settings.py (do not, under any
circumstances, re-use the actual example value of SECRET_KEY here!) and
make to set these three settings:
SECRET_KEY = 'iLNScMiUpNy5hditWAp9e2dyHGTFoX44UKsbhj91f9xL4fdJSDY'
TIME_ZONE = 'Europe/Oslo' # This should correspond to your actual timezone, also as in nav.conf
DATABASES = {
'default': {
'NAME': 'graphite',
'ENGINE': 'django.db.backends.postgresql_psycopg2',
'USER': 'graphite',
'PASSWORD': 'the password you made note of above',
'HOST': 'localhost',
'PORT': '5432'
}
}
Now make graphite-web initialize its database schema:
sudo -u _graphite graphite-manage migrate auth --noinput
sudo -u _graphite graphite-manage migrate --run-syncdb --noinput
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