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Running Beacon

The Beacon process starts multiple servers:

  • Configuration database server
  • Redis servers (settings and data)
  • (optional) configuration web application server
  • (optional) TANGO database server
  • (optional) Log server

Beacon at ESRF (auto-started)

At ESRF, the BLISS installation procedure automatically adds Beacon to the daemons started by the system:

  • The port number for the Beacon server is set to 25000
  • The Redis settings server is started on port 25001
  • The Redis data server is started on port 25002
  • The configuration files directory is set to /users/blissadm/local/beamline_configuration
  • The configuration web application is available at http://localhost:9030
  • The Beacon TANGO database service is disabled (else port 20000)
  • The LogServer service is disabled by default (else port 9020)
  • The LogViewer application is usually available at http://localhost:9080 (disable by default)


At ESRF there is at least one Beacon server per beamline.

Starting Beacon manually

While starting manually, specify the path to the configuration files with --db-path.

On a beamline at the ESRF:

beacon-server --db-path=~/local/beamline_configuration

Or within a test environement:

beacon-server --db-path=~/bliss/tests/test_configuration

The Beacon port number --port can be set manually (usually 25000 at ESRF, default is chosen by the system).

beacon-server --db-path=~/local/beamline_configuration --port=25000

Beacon implements a discovery protocol (in the same spirit as SSDP). Therefore, by default, clients trying to access the server will connect to the first Beacon found on their sub-network.

However, it is safer to specify where to connect explicitly, using the BEACON_HOST environment variable to point to <machine>:<port>.

Example, before starting a bliss session, set the BEACON_HOST environment variable:

export BEACON_HOST=bibehlm:25000
bliss -s mysession

Display the current value of the environment variable with echo $BEACON_HOST.


BLISS relies on two Redis servers, each dealing with one redis database:

  • --redis-port: settings server port is 25001 at the ESRF and default is 6379. Works with Redis database 0.
  • --redis-data-port: data server port is 25002 at the ESRF and default is 6380. Works with Redis database 1.
beacon-server --db-path=~/local/beamline_configuration --redis-port=25001 \
              --redis-data-port=25002 --port=25000

Custom Redis configuration file can be specified with --redis-config and --redis-data-config arguments:

beacon-server --db-path=~/local/beamline_configuration \
              --redis-port=25001 \
              --redis-data-port=25002 \
              --redis-conf=~/local/redis.conf  \

Custom configuration file allow to change redis settings like maxmemory or I/O threads in a local configuration file.


Port numbers in redis configuration file will be ignored, always specify --redis-port and --redis-data-port to customize the redis listening ports.

Web application

The configuration files managed by the Beacon server can be edited via a web application.

Enable the web application by specifying the port number --webapp-port (9030 at ESRF):

beacon-server --db-path=~/local/beamline_configuration --webapp-port=9030 \
              --redis-port=25001 --redis-data-port=25002 --port=25000


Beacon server is also able to provide a simple TANGO database server service (with reduced functionality compared to the Tango DataBase device server for MariaDB) that integrates nicely with the BLISS configuration.

Start the service by providing the port number --tango-port (20000 at ESRF):

beacon-server --db-path=~/local/beamline_configuration --tango-port=20000 \
              --webapp-port=9030 --redis-port=25001 --redis-data-port=25002 \

Tango clients can specify the TANGO_HOST environment variable:

export TANGO_HOST=bibehlm:20000
export BEACON_HOST=bibehlm:25000
bliss -s mysession


At ESRF, the standard setup is to use the C++ version of the Tango DataBase device server for production on beamlines to ensure all features are implemented.


MySql Tango database can be exported using: scripts/ It requires mysqldb python module (mamba install mysqlclient to install it.)

YAML Tango resource file example

YAML resource files have to be placed in ~/local/beamline_configuration/tango/ directory and beacon-server has to be restarted.

server: GpibController_PCI
personal_name: ldcm1
- tango_name: id42/gpib_ldcm1/0
  class: GpibController
    gpibBoardName: gpib0
    gpibDeviceTimeOut: '13'
    lowLevelDebugFlag: 'false'

Log Server and Log Viewer

A Log Server service is given with the purpose of receiving log messages from multiple clients and writing them to rotating files.

Beacon will create one log file per session and will rotate on a given size (default 10MB).

Also a Log Viewer Web Application is provided for reading log files.

Enable the Log Server and Viewer by providing the port numbers --log-server-port and --log-viewer-port.

The Viewer cannot be started if the Log Server is not started.

beacon-server --db-path=~/local/beamline_configuration --log-server-port=9020 \
              --log-viewer-port=9080 --tango-port=20000 --webapp-port=9030 \
              --redis-port=25001 --redis-data-port=25002 --port=25000

Additional options can be set to change the output log folder (that normally is on /var/log/bliss) and the size of files (default 10MB).

Command line options

  • --db-path: the root path of the configuration files, default is ./db or $BEACON_DB_PATH if defined.
  • --port: the tcp port for the beacon server, default is 25000 or $BEACON_PORT if defined.
  • --redis-port: the port for the redis settings server, default is 6379.
  • --redis-data-port: the port for the redis data server, default is 6380.
  • --redis-conf: redis configuration file, default is bliss/config/redis/redis.conf
  • --redis-data-conf: data redis configuration file, default is bliss/config/redis/redis_data.conf
  • --redis-socket uds redis connection, default is /tmp/redis.sock
  • --tango-port: set the tango database server port and activate the service.
  • --tango-debug-level: default is 0 WARNING == 1, INFO == 2, DEBUG == 2
  • --webapp-port: set the webapp server port and activate the service.
  • --log-server-port: set the log server port and activate the service (generates log files).
  • --log-output-folder: an existing folder to store log files (usually /var/log/bliss).
  • --log-viewer-port if defined, start the Web Applications tailon on specified port.
  • --log-level: set the logging level [DEBUG, INFO, WARN, ERROR] (default is INFO).