Skip to content

Setting up RRDCached

This document will explain how to set up RRDCached for LibreNMS.

Since version 1.5, rrdtool / rrdcached now supports creating rrd files over rrdcached. If you have rrdcached 1.5.5 or above, you can also tune over rrdcached. To enable this set the following config:

$config['rrdtool_version'] = '1.5.5';
This setting has to be the exact version of rrdtool you are running.

NOTE: This feature requires your client version of rrdtool to be 1.5.5 or newer, in addition to your rrdcached version.

Distributed Poller Support Matrix

Shared FS: Is a shared filesystem required?

Features: Supported features in the version indicated.

G = Graphs.
C = Create RRD files.
U = Update RRD files.
T = Tune RRD files.
Version Shared FS Features
1.4.x Yes G,U
<1.5.5 Yes G,U
>=1.5.5 No G,C,U
>=1.6.x No G,C,U

It is recommended that you monitor your LibreNMS server with LibreNMS so you can view the disk I/O usage delta.

Installation Manual for

  1. RRDCached installation Ubuntu 16
  2. RRDCached installation Debian Buster
  3. RRDCached installation Debian Stretch
  4. RRDCached installation CentOS 7 or 8
  5. RRDCached installation CentOS 6
  6. Securing RRCached

RRDCached installation Ubuntu 16

1: Install rrdcached

sudo apt-get install rrdcached

2: Edit /etc/default/rrdcached to include:

DAEMON=/usr/bin/rrdcached
DAEMON_USER=librenms
DAEMON_GROUP=librenms
WRITE_THREADS=4
WRITE_TIMEOUT=1800
WRITE_JITTER=1800
BASE_PATH=/opt/librenms/rrd/
JOURNAL_PATH=/var/lib/rrdcached/journal/
PIDFILE=/run/rrdcached.pid
SOCKFILE=/run/rrdcached.sock
SOCKGROUP=librenms
BASE_OPTIONS="-B -F -R"

2: Fix permissions

chown librenms:librenms /var/lib/rrdcached/journal/

3: Restart the rrdcached service

systemctl restart rrdcached.service

5: Edit /opt/librenms/config.php to include:

$config['rrdcached'] = "unix:/run/rrdcached.sock";

RRDCached installation Debian Buster

(rrdcached 1.7.1)

1: Install rrdcached

sudo apt-get install rrdcached

2; Edit /etc/default/rrdcached to include:

DAEMON=/usr/bin/rrdcached
WRITE_TIMEOUT=1800
WRITE_JITTER=1800
WRITE_THREADS=4
BASE_PATH=/opt/librenms/rrd/
JOURNAL_PATH=/var/lib/rrdcached/journal/
PIDFILE=/var/run/rrdcached.pid
SOCKFILE=/run/rrdcached.sock
SOCKGROUP=librenms
DAEMON_GROUP=librenms
DAEMON_USER=librenms
BASE_OPTIONS="-B -F -R"

3: Fix permissions

chown librenms:librenms /var/lib/rrdcached/journal/

4: Restart the rrdcached service

systemctl restart rrdcached.service

5: Edit /opt/librenms/config.php to include:

For local RRDCached server

$config['rrdcached'] = "unix:/run/rrdcached.sock";

For remote RRDCached server make sure you have network option in /var/default/rrdcached

NETWORK_OPTIONS="-L"
$config['rrdcached'] = "IPADDRESS:42217";

NOTE: change IPADDRESS to the ip the rrdcached server is listening on.

RRDCached installation Debian Stretch

(rrdcached 1.6.0)

1: Install rrdcached

sudo apt-get install rrdcached

2; Edit /etc/default/rrdcached to include:

DAEMON=/usr/bin/rrdcached
WRITE_TIMEOUT=1800
WRITE_JITTER=1800
WRITE_THREADS=4
BASE_PATH=/opt/librenms/rrd/
JOURNAL_PATH=/var/lib/rrdcached/journal/
PIDFILE=/var/run/rrdcached.pid
SOCKFILE=/run/rrdcached.sock
SOCKGROUP=librenms
DAEMON_GROUP=librenms
DAEMON_USER=librenms
BASE_OPTIONS="-B -F -R"

3: Fix permissions

chown librenms:librenms /var/lib/rrdcached/journal/

4: Restart the rrdcached service

systemctl restart rrdcached.service

5: Edit /opt/librenms/config.php to include:

For local RRDCached server

$config['rrdcached'] = "unix:/run/rrdcached.sock";

For remote RRDCached server make sure you have network option in /var/default/rrdcached

NETWORK_OPTIONS="-L"
$config['rrdcached'] = "IPADDRESS:42217";

NOTE: change IPADDRESS to the ip the rrdcached server is listening on.

RRDCached installation CentOS 7 or 8

1: Create /etc/systemd/system/rrdcached.service with this content:

[Unit]
Description=Data caching daemon for rrdtool
After=network.service

[Service]
Type=forking
PIDFile=/run/rrdcached.pid
ExecStart=/usr/bin/rrdcached -w 1800 -z 1800 -f 3600 -s librenms -U librenms -G librenms -B -R -j /var/tmp -l unix:/run/rrdcached.sock -t 4 -F -b /opt/librenms/rrd/

[Install]
WantedBy=default.target

2: Start rrdcached

systemctl enable --now rrdcached.service

3: Edit /opt/librenms/config.php to include:

$config['rrdcached'] = "unix:/run/rrdcached.sock";

RRDCached installation CentOS 6

This example is based on a fresh LibreNMS install, on a minimal CentOS 6 installation. In this example, we'll use the Repoforge repository.

rpm -ivh http://pkgs.repoforge.org/rpmforge-release/rpmforge-release-0.5.3-1.el6.rf.x86_64.rpm
vi /etc/yum.repos.d/rpmforge.repo
  • Enable the Extra repo
yum update rrdtool
vi /etc/yum.repos.d/rpmforge.repo
  • Disable the [rpmforge] and [rpmforge-extras] repos again
vi /etc/sysconfig/rrdcached

# Settings for rrdcached
OPTIONS="-w 1800 -z 1800 -f 3600 -s librenms -U librenms -G librenms -B -R -j /var/tmp -l unix:/run/rrdcached.sock -t 4 -F -b /opt/librenms/rrd/"
RRDC_USER=librenms

mkdir /var/run/rrdcached
chown librenms:librenms /var/run/rrdcached/
chown librenms:librenms /var/rrdtool/
chown librenms:librenms /var/rrdtool/rrdcached/
chkconfig rrdcached on
service rrdcached start
  • Edit /opt/librenms/config.php to include:
$config['rrdcached']    = "unix:/run/rrdcached.sock";

Verify

Check to see if the graphs are being drawn in LibreNMS. This might take a few minutes. After at least one poll cycle (5 mins), check the LibreNMS disk I/O performance delta. Disk I/O can be found under the menu Devices>All Devices>localhost hostname>Health>Disk I/O.

Depending on many factors, you should see the Ops/sec drop by ~30-40%.

Securing RRCached

According to the man page, under "SECURITY CONSIDERATIONS", rrdcached has no authentication or security except for running under a unix socket. If you choose to use a network socket instead of a unix socket, you will need to secure your rrdcached installation. To do so you can proxy rrdcached using nginx to allow only specific IPs to connect.

Using the same setup above, using nginx version 1.9.0 or later, you can follow this setup to proxy the default rrdcached port to the local unix socket.

(You can use ./conf.d for your configuration as well)

mkdir /etc/nginx/streams-{available,enabled}

add the following to your nginx.conf file:

#/etc/nginx/nginx.conf
...
stream {
    include /etc/nginx/streams-enabled/*;
}

Add this to /etc/nginx/streams-available/rrd

server {
    listen 42217;

    error_log  /var/log/nginx/rrd.stream.error.log;

    allow $LibreNMS_IP;
    deny all;

    proxy_pass unix:/run/rrdcached.sock;
}

Replace $LibreNMS_IP with the ip of the server that will be using rrdcached. You can specify more than one allow statement. This will bind nginx to TCP 42217 (the default rrdcached port), allow the specified IPs to connect, and deny all others.

next, we'll symlink the config to streams-enabled: ln -s /etc/nginx/streams-{available,enabled}/rrd

and reload nginx service nginx reload

Back to top