Node Configuration

Fed-BioMed framework has 2 main components: node and researcher. A node stores private datasets and performs training in response to researcher's train requests. It communicates directly with the researcher component using RPC protocol.

A basic node component configuration contains the following settings:

• a python environment
• a unique node id
• security parameters such as training plan approval mode, hashing algorithms
• connection credentials for the researcher component

Environment for Nodes

A node requires a conda environment to be able to run. This environment provides necessary python modules for both the task management part and the model training part. Thanks to Fed-BioMed Node CLI, this conda environment can be created easily.

$ ${FEDBIOMED_DIR}/scripts/configure_conda

The command above creates three different environments including fedbiomed-node. You can see details in installation tutorial. This documentation will focus more on configuration steps.

Note: FEDBIOMED_DIR represents the path of the base Fed-BioMed project directory.

Configuration Files

A configuration file is an ini file that is located in${FEDBIOMED_DIR}/etc directory. It contains the variables that are required for starting a single node. Please see the sections and the corresponding variables of a basic configuration file for a node.

• Default Parameters:

  • id: This is the unique ID that identifies the node.
  • component: Specifies the component type. It is always NODE for node component
  • version: Version of the configuration format to avoid using older configuration files with recent Fed-BioMed versions.

• Researcher:

  • ip: The IP address of the researcher component that the node will connect to.
  • port: The port of the researcher component.

• Security Parameters:

• hashing_algorithm: The algorithm will be used for hashing training plan scripts to verify if the requested training plan matches the one approved on the node side.
• training_plan_approval: Boolean value to switch training plan approval to verify training plan scripts before the training.
• allow_default_training_plans: Boolean value to enable automatic approval of example training plans provided by Fed-BioMed.
• secure_aggregation: Boolean parameter (True/False) to activate secure aggregation.

• force_secure_aggregation: Boolean parameter (True/False) to force secure aggregation for every action that uses local dataset.

• MPSDPZ (Secure Aggregation)

• MP-SDPZ is the library used for secure aggregation to be able to generate private/public keys securely. Please see the details Here.
• private_key: Path to private key to use in secure HTTP connection.
• public_key: Path to public key to share with other parties (nodes and researcher) use in secure HTTP connection.
• mpspdz_ip: The IP address that will be used for launching MP-SPDZ instance.
• mpsdpz_port: The port that will be used for launching MP-SPDZ instance.
• allow_default_biprimes: Boolean (True/False) to allow default biprimes for key generation.

An example for a config file is shown below;

[default]
id = node_73768d5f-6a66-47de-8533-1291c4ef59d1
component = NODE
version = 2

[security]
hashing_algorithm = SHA256
allow_default_training_plans = True
training_plan_approval = False
secure_aggregation = True
force_secure_aggregation = False

[researcher]
ip = localhost
port = 50051

[mpspdz]
private_key = certs/cert_node_73768d5f-6a66-47de-8533-1291c4ef59d1/MPSPDZ_certificate.key
public_key = certs/cert_node_73768d5f-6a66-47de-8533-1291c4ef59d1/MPSPDZ_certificate.pem
mpspdz_ip = localhost
mpspdz_port = 14004
allow_default_biprimes = True

Starting Nodes with Config Files

Currently, creating config files is done by the fedbiomed_run script. It automatically creates config files based on values assigned in the fedbiomed.node.environ. Starting nodes with specific config creates a new configuration file. The following command creates a specific config file with default settings and starts the node.

$ ./scripts/fedbiomed_run node config config-n1.ini start

If you run this command, you can see a new config file created in the etc/ directory of the Fed-BioMed. Each node that runs in the same host should have a different node id and configuration file. Starting another node that uses the same config file with another raises errors. Therefore, if you launch multiple nodes please
make sure to use different configurations.

Listing and adding datasets follows the same logic. If you want to list or add datasets in the nodes that is different from the default one, you need to specify the config file.

$ ./scripts/fedbiomed_run node config config-n1.ini list
$ ./scripts/fedbiomed_run node config config-n1.ini add

Creating advanced configuration files for node components

The script ${FEDBIOMED_DIR}/scripts/fedbiomed_run configuration create -c NODE -n [CONFIGURATION_FILE_NAME] will create or optionally recreate (-f) a configuration file for a node with CONFIGURATION_FILE_NAME name in the ${FEDBIOMED_DIR}/etc folder. More options are available and described through the help menu: ${FEDBIOMED_DIR}/scripts/fedbiomed_run configuration create -h The parametrization of this script with regard to the various fields stored in the configuration happens through the usage of environment variables. The fields that can be controlled, their associated evironment variable and default value are described as follow:

[security]: - allow_default_training_plans: ALLOW_DEFAULT_TRAINING_PLANS, True - training_plan_approval: ENABLE_TRAINING_PLAN_APPROVAL, False - secure_aggregation: SECURE_AGGREGATION, True - force_secure_aggregation: FORCE_SECURE_AGGREGATION, False

[researcher]: - ip: RESEARCHER_SERVER_HOST, ${IP_ADDRESS}, if not set: localhost - port: RESEARCHER_SERVER_PORT, 50051

Examples:

$ RESEARCHER_SERVER_HOST=121.203.21.147 RESEARCHER_SERVER_PORT=8909 SECURE_AGGREGATION=0 ${FEDBIOMED_DIR}/scripts/fedbiomed_run configuration create -c NODE -n node_1.ini -f

Note that recreating (-f) a configuration file will override the whole file including the node id. To preserve the node id across updates of the configuration file, prefer using ${FEDBIOMED_DIR}/scripts/fedbiomed_run configuration refresh -c NODE -n node_1.ini.