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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

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)

Info

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

Start Beacon server

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

On a beamline at the ESRF: 

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

Or within a test environment: 

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 & BLISS sessions

BLISS uses the BEACON_HOST environment variable to identify which Beacon server should be used. Therefore, before staring a BLISS session, this environment variable must be set to a given <hostname>:<port>, with <hostname> the name of the machine running the Beacon server target.

Set the BEACON_HOST environment variable

export BEACON_HOST=localhost:25000  # for a Beacon server running locally
export BEACON_HOST=idxx:25000       # for a Beacon server running on idxx computer

Display the current value of the BEACON_HOST

echo $BEACON_HOST

Now the bliss command will use the current BEACON_HOST to retrieve information about available sessions defined in the configuration files loaded by the Beacon server.

Display available BLISS sessions

bliss -s

Available BLISS sessions:
-------------------------
exp
optics
test_session

Start a BLISS session

bliss -s optics

Redis

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  \
              --redis-data-conf=~/local/redis_data.conf

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

Note

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

BLISS uses 2 extra Redis extension modules: RediSearch and RedisJSON. When BLISS is installed with Conda packages, those are included in requirements and can be found automatically by Beacon, which adds 2 --loadmodule directives in the Redis command line at startup: there is nothing special to do. If the modules are not installed via Conda, please add a custom Redis configuration file for both instances (--redis-config and --redis-data-config) with the following:

loadmodule /path/to/redisearch.so
loadmodule /path/to/librejson.so

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

Tango

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 \
              --port=25000

Tango clients can specify the TANGO_HOST environment variable:

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

Note

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.

Note

MySql Tango database can be exported using: scripts/tango_mysql_dump.py. 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
device:
- tango_name: id42/gpib_ldcm1/0
  class: GpibController
  properties:
    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).