Internal DB/Raid System

This system is a Synology RAID system (specifically RS3412RPxs), with 10 4-TB disks. 8 of these disks provide RAID6 (total ~22 TB of space) with 2 disks acting as hot spares. The system runs a linux distribution (DSM) and is generally administrated either from the command line (e.g. ssh) or via a web interface.

Administration screen of raid system

This system provides the following features:

Central experimental control database, central CouchDB database for experimental control and slow-control variables.
OpenVPN, VPN access to the internal network from external locations
NFS/CIFS File Server network drive for data files
File Synchronization of files to the cluster DB.
CouchDB Monitoring, monitoring of the CouchDB database using munin

Required Packages

Synology DSM provides software bundled in packages which allows for easy installation. The central server requires:

Cloud Station - Automatic synchronization of files to the Cluster DB.
Docker - ‘Virtualization’ program allowing deployment of ‘containers’ housing separate programs.
RADIUS Server - Authentication for VPN server.
VPN Server - Virtual private network

Control DB

The control database consists of the following components:

CouchDB database
ngingx reverse proxy with file server

Both of these components run in two separate (but connected) Docker containers on the server. More details regarding this system are presented on the slow control DB page.

OpenVPN

An OpenVPN server runs on the central server, providing access to the internal network from external sites. The connection is made available to public computers by remote forwarding an ssh tunnel (see e.g. here) to ucgate.universe-cluster.de. This is done using an autossh daemon on the gateway machine.

Connection information to the OpenVPN is available on the wiki.

The only file necessary to configure this is /usr/syno/etc/packages/VPNCenter/openvpn/openvpn.conf (available on the wiki). Note that the two Synology Packages must be installed for this to work:

VPN Server - provides the actual OpenVPN server
Radius Server - provides authentication of users.

NFS File Server

This provides simply a network drive for storage of files. Note, this should not be confused with the file server associated with the control database.

File synchronization

File sychronization happens behind the scenes using the Cloud Station. This synchronizes files that are saved using the nginx File Server. To enable this, a port is tunneled to optimal.universe-cluster.de using autossh.

There is also a script that runs on this server which corrects the permissions of the files. Otherwise these files are not transferred using CloudStation. The script is configured in Control Panel -> Task Scheduler to run every hour.

find /volume1/Measurements/nedm -user root -type d -exec chmod 775 {} \; 
find /volume1/Measurements/nedm -user root -type f -exec chmod 664 {} \; 
find /volume1/Measurements/nedm -user root -exec chown meas_daemon:users {} \;

This synchronizes files located in /volume1/Measurements.

CouchDB Monitoring

The CouchDB server is monitored via a docker container containing a munin process. This tracks several metrics which can be important when monitoring usage or tracking down problems. The site is available here.

Screenshot of Munin Monitoring .

Setting up the monitoring requires several steps.

Ensure the CouchDB and associated File Server are running. See here.
Download (using the DSM interface) the docker container: mgmarino/munin-docker:latest. Run this with the execution command: echo "Munin Data Container" and name the container munin-data-container. (Note: This provides the static file structure to save the data from the munin process. This container should run once and exit.)

docker run\
  --name munin-data-container\
  mgmarino/munin-docker\
  echo "Munin Data Container"

Start the the munin daemon container:

docker run -d -p 81:80\
  --volumes-from munin-data-container\
  --name munin --link nEDM-FileServer:db \
  registry.hub.docker.com/mgmarino/munin-docker:latest

Note: here we have assumed that the nEDM-FileServer (see here) is running with the name: nEDM-FileServer.

More details about the munin container can be found here.

WiFi/WLAN

The wireless internet dongle runs on the Synology server, giving access to the nEDM network in the Osthalle.

System Overview

Sub-pages: