Configuration

Configuration options are located in a JSON file. Default path is config.json in current working directory. Alternative paths to the configuration file can be specified using the command line switch -config <filename>.

All durations are specified as string that will be parsed like this (Allowed suffixes: s, m, h, …).

The configuration is organized into four main sections: main, metrics, nats, and metric-store.

Main Section

• main: Server configuration (required)
  • addr: Address to bind to, for example localhost:8080 or 0.0.0.0:443 (required)
  • https-cert-file: Filepath to SSL certificate. If also https-key-file is set, use HTTPS (optional)
  • https-key-file: Filepath to SSL key file. If also https-cert-file is set, use HTTPS (optional)
  • user: Drop root permissions to this user once the port was bound. Only applicable if using privileged port (optional)
  • group: Drop root permissions to this group once the port was bound. Only applicable if using privileged port (optional)
  • backend-url: URL of cc-backend for querying job information, e.g., https://localhost:8080 (optional)
  • jwt-public-key: Base64 encoded Ed25519 public key, use this to verify requests to the HTTP API (required)
  • debug: Debug options (optional)
    • dump-to-file: Path to file for dumping internal state (optional)
    • gops: Enable gops agent for debugging (optional)

Metrics Section

• metrics: Map of metric-name to objects with the following properties (required)
  • frequency: Timestep/Interval/Resolution of this metric in seconds (required)
  • aggregation: Can be "sum", "avg" or null (required)
    • null means aggregation across topology levels is disabled for this metric (use for node-scope-only metrics)
    • "sum" means that values from the child levels are summed up for the parent level
    • "avg" means that values from the child levels are averaged for the parent level

NATS Section

• nats: NATS server connection configuration (optional)
  • address: URL of NATS.io server, example: nats://localhost:4222 (required if nats section present)
  • username: NATS username for authentication (optional)
  • password: NATS password for authentication (optional)

Metric-Store Section

• metric-store: Storage engine configuration (required)
  • retention-in-memory: Keep all values in memory for at least that amount of time. Should be long enough to cover common job durations (required)
  • memory-cap: Upper memory capacity limit used by the metric store in GB (required). If exceeded, buffers still in use by long-running jobs will be freed.
  • num-workers: Number of concurrent workers for checkpoint and archive operations (optional). Defaults to min(NumCPU/2+1, 10).
  • checkpoints: Checkpoint configuration (optional)
    • file-format: Format for checkpoint files. Either "json" (human-readable, periodic) or "wal" (binary snapshot + Write-Ahead Log, crash-safe). Default: "wal" (optional)
    • directory: Path to checkpoint directory. Default: ./var/checkpoints (optional)
  • cleanup: Cleanup/archiving configuration (optional). The cleanup interval always equals retention-in-memory. Defaults to mode: delete if not set.
    • mode: Either "archive" (move old checkpoints to archive directory) or "delete" (remove old checkpoints). Default: "delete" (optional)
    • directory: Path to archive directory (required if mode is "archive")
  • nats-subscriptions: Array of NATS subscription configurations (optional, requires nats section)
    • subscribe-to: NATS subject to subscribe to (required)
    • cluster-tag: Default cluster tag for metrics without a cluster tag (optional)