lccfq-backend

Stateful, queueing backend to connect an HPC system to a QPU.

Setup

Copy the example config and edit it for your environment:

cp configs/example_config.toml config.toml

CLI

All commands are run via uv run backend.

Starting the server

uv run backend start
uv run backend start -c /path/to/config.toml

Certificate management

Server certificates must be set up before starting the server. Client certificates are issued to users who need to connect to the backend's gRPC API.

Set up CA and server certificates:

uv run backend cert setup-server
uv run backend cert setup-server --cert-dir ./certs --hostname localhost

Create a client certificate for a user:

uv run backend cert create-client <user_id>
uv run backend cert create-client <user_id> --cert-dir ./certs

List existing client certificates:

uv run backend cert list-clients

Check server certificate status:

uv run backend cert status

Logging

Log level is set via log_level in config.toml. It can also be overridden with the LCCFQ_LOG_LEVEL environment variable. Additional options:

Variable	Description
LCCFQ_LOG_LEVEL	Global log level (DEBUG, INFO, WARNING, ERROR)
LCCFQ_LOG_LEVELS	Per-component overrides, e.g. lccfq.executor=DEBUG,lccfq.hwman=WARNING
LCCFQ_LOG_FORMAT	text (default) or json
LCCFQ_LOG_FILE	Path to log file (enables rotating file handler)