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Welcome to the ECS wiki!

Dependencies:

• python3.7
• django
• zmq
• paramiko
• django-guardian
• django-widget-tweaks
• zc.lockfile
• sqlite3

ECA and Webserver

The Experiment-Control-Agent(ECA) is the highest process on the ECS hierarchie and controlls the entire Experiment. It manages a set Partition-Control-Agents(PCA) and the database for configurations and detector partition-assignments. It provides a user interface via a webserver and the django framework. The ECA runs as a subprocess of the Webserver. Settings like options or ports for the ECA and Webserver can be found in Django/ECS_GUI/ECS_GUI/settings.py.

The ECS components (ECA,PCA,subsystem controller) can be run distributed on several computing nodes. The components get connection data from the ECS database therefore they need the address and communication ports of the ECS. The Hostaddress and Ports of the ECA/Webserver must be set in Django/ECS_GUI/ECS_GUI/settings.py and in the init.cfg.

Django includes a lightweight webserver for debugging purposes it can be run via python3 Django/ECS_GUI/manage.py runserver.

For non-debugging usage the django webserver should not be used, instead the Application should be deployed over WSGI on an apache or nginx server with SSL Encryption.

Deploying on apache2 with ssl encryption:

• copy Project to e.g. /var/www/ECS
• create a SSL Certificate e.g. /etc/apache2/ssl/crt/apache.crt and a Key e.g. /etc/apache2/ssl/key/apache.key
• create a file /etc/apache2/sites-available/ECS.conf and add something like this:

<VirtualHost *:80>
        #redirect all HTTP requests to HTTPS
        ServerName localhost
        ServerAdmin admin@example.com

        # Redirect Requests to SSL
        Redirect permanent "/" "https://localhost/"
        
	ErrorLog ${APACHE_LOG_DIR}/errorECS.log
        CustomLog ${APACHE_LOG_DIR}/accessECS.log combined

</VirtualHost>

<VirtualHost *:443>
	ServerName localhost

	ServerAdmin webmaster@localhost
	DocumentRoot /var/www/ECS

	# Available loglevels: trace8, ..., trace1, debug, info, notice, warn,
	# error, crit, alert, emerg.
	# It is also possible to configure the loglevel for particular
	# modules, e.g.
	#LogLevel info ssl:warn

	ErrorLog ${APACHE_LOG_DIR}/errorECS.log
	CustomLog ${APACHE_LOG_DIR}/accessECS.log combined
	
        SSLEngine on

        SSLCertificateFile /etc/apache2/ssl/crt/apache.crt
        SSLCertificateKeyFile /etc/apache2/ssl/key/apache.key

	# For most configuration files from conf-available/, which are
	# enabled or disabled at a global level, it is possible to
	# include a line for only one particular virtual host. For example the
	# following line enables the CGI configuration for this host only
	# after it has been globally disabled with "a2disconf".
	#Include conf-available/serve-cgi-bin.conf
	WSGIScriptAlias / /var/www/ECS/Django/ECS_GUI/ECS_GUI/wsgi.py
	WSGIDaemonProcess test python-home=<Path to virtuel python enviroment> python-path=/var/www/ECS/Django/ECS_GUI/ home=/var/www/ECS/ user=<username>
	WSGIProcessGroup test

	<Directory /var/www/ECS/Django/ECS_GUI/ECS_GUI/>
		<Files wsgi.py>
			Require all granted
		</Files>
	</Directory>

	Alias /static/ /var/www/ECS/Django/ECS_GUI/GUI/static/

	<Directory /var/www/ECS/Django/ECS_GUI/GUI/static/>
		Require all granted
	</Directory>

</VirtualHost>

• and must be changed acordingly
• run sudo a2ensite ECS and sudo systemctl reload apache2
• in ECS/Django/ECS_GUI/ECS_GUI/settings.py set PATH_TO_PROJECT = "/var/www/ECS" and PATH and LOG_PATH_ECS = "/var/www/ECS/logECS" and ENCRYPT_WEBSOCKET=False and SSL_CERT_FILE="/etc/apache2/ssl/crt/apache.crt" and SSL_PEM_FILE="/etc/apache2/ssl/key/apache.key"

PCA

The Partition-Control-Agent(PCA) manages a Partition of detectors and global subsystems. Basic settings for the PCA can be found in the init.cfg file. The PCA manages a global state for the partition in a finite state machine. The graph for the FSM is generated over the PCAStatemachine.csv file. Changes to the PCA state machine will most likely require in the states.py file which (for the most part) assigns the states of the csv to python variables. Furthermore a state machine change will likely require changes to the function checkGlobalState (probably more) in PCA.py.

The PCA client can be startet by typing ./PCA.py <pca id> while replacing <pca id> with the actual partition name.

The PCA client can also be started automatically by the ECA be setting START_CLIENTS = True in the Django/ECS_GUI/ECS_GUI/settings.py file. The ECA then tries to start the clients over ssh. It is required that the user who runs the ECA can login into the target node without entering his/her password.

Client Agents

Client Agents are the interface to the actual experiment subssytems like detectors. There is a separation between detectors which belong to exactly one partition and global systems like the DCS which belong to all partitions. Basic settings for subsystem controller can be found in subsystem.cfg. Each subsystem has it's own state machine. These FSMs are again provided in csv files. Again changes to these will most likely also require changes to states.py and DetectorController.py or GlobalSystemClient.py.

Detectors can be startet by ./DetectorController.py -s <startState> -c <startConfig> <detector Id>.

Global Systems can be startet by ./GlobalSystem.py -s <startState> -o <startConfig> <System (TFC,DCS,QA,FLES or all)>

The options startState and startConfig should only be used for debugging the controller should get the actual state from the subsystem itself .

starting scripts

There are several start scripts for the ECS.

• The script demo.sh starts a set demo detector dummys.
• start.sh <number of detectors> starts n detectors with ascending numeric ids.
• startSlurm.sh <number of detectors> starts n detectors,a test PCA and Global Systems in an SLURM cluster. It executes the scripts pca_and_globalSystem_start.sh and detectorStart.sh on the SLURM nodes

The python script Django/ECS_GUI/createTestPCA.py can be used to quickly create a test partition with a large number of detectors, which run distributed in a SLURM cluster.