# =====================================================================
# Node identity
# =====================================================================
node:
  # [Required]
  # Unique and stable identifier for this node within the cluster.
  # This value must be globally unique and must not change across restarts.
  # It is used as the node's identity in vnode ownership, routing,
  # rebalance planning, and all cluster‑wide coordination.
  # The identifier should be explicit (e.g., 'node-1', 'db-a', 'shard-3') and
  # must not depend on ephemeral properties such as IP address or hostname.
  id: "node-1"

  # [Default: L]
  # Size class defining how many virtual slots (vnodes) this node receives
  # when generating its vnode assignment for the first time.
  #
  # IMPORTANT:
  #   - This value is used ONLY if the storage backend does NOT already contain
  #     a persisted vnode list.
  #   - Once a vnode list exists on disk, it becomes the authoritative source
  #     of truth and this field is ignored.
  #
  # Allowed values:
  #   XS  → 1 slot
  #   S   → 2 slots
  #   M   → 4 slots
  #   L   → 8 slots
  #   XL  → 16 slots
  #   XXL → 32 slots
  size: "L"


# =====================================================================
# Server settings (TCP + TLS)
# =====================================================================
server:
  api:
    # [Default: 127.0.0.1]
    # Host/IP on which the client-facing API listens.
    # This is the bind address used locally by the OS.
    host: "127.0.0.1"

    # [Default: 2000]
    # TCP port for client requests (GET/PUT).
    port: 2000

  peer:
    # [Default: 127.0.0.1]
    # Host/IP on which the inter-node server listens.
    host: "127.0.0.1"

    # [Default: 6000]
    # TCP port used for inter-node communication:
    # join, leave, sync/view, replication, handoff, partition transfers.
    port: 6000

    # [Default: []]
    # List of seed node addresses (host:port) used during bootstrap.
    # At startup, this node will contact the listed seeds to obtain the current
    # cluster membership and ring layout.
    #
    # Seeds are only used during bootstrap. After join, the node no longer
    # depends on them.
    seeds: []

    # [Optional]
    # Reachable address (host:port) advertised to other nodes.
    # This is the canonical address peers will use to contact this node.
    # If omitted, defaults to '<server.peer.host>:<server.peer.port>'.
    listener: "127.0.0.1:6000"

  tls:
    # [Required]
    # Path to the node's TLS certificate (PEM).
    # Used for both client and peer servers.
    certfile: ""

    # [Required]
    # Path to the node's TLS private key (PEM).
    keyfile: ""

    # [Required]
    # Path to the CA certificate (PEM) used to verify client and peer certificates.
    cafile: ""

  # [Default: 128]
  # Maximum number of pending TCP connections allowed by the OS.
  backlog: 128

  # [Default: 5.0]
  # Maximum time (in seconds) allowed for a graceful shutdown.
  timeout_graceful_shutdown: 5.0

  # [Default: 1024]
  # Maximum number of concurrent in-flight requests handled by the node.
  limit_concurrency: 1024

  # [Default: 4194304 (4MB)]
  # Maximum allowed buffer size for incoming data (in bytes).
  max_buffer_size: 4194304

  # [Default: 1048576 (1MB)]
  # Maximum allowed size for a single decoded message (in bytes).
  max_message_size: 1048576


# =====================================================================
# Storage settings
# =====================================================================
storage:
  # [Required]
  # Directory where the node stores all persistent data.
  # Must exist or be creatable, writable, and persistent across restarts.
  data_dir: ""

  # [Optional: storage.data_dir]
  # Directory where incoming partitions
  # are written before being atomically swapped into place.
  # If omitted, defaults to "<storage.data_dir>".
  replication_dir: ""


# =====================================================================
# Placement / Ring configuration
# =====================================================================
placement:
  # [Default: 16]
  # Shift factor used to compute the total number of logical partitions (Q).
  # Q = 1 << shift
  #
  # This value MUST remain stable for the lifetime of the cluster.
  shift: 16

  # [Default: 3]
  # Number of distinct nodes that must store each partition.
  # A replication_factor of N means each key is stored on N different nodes.
  replication_factor: 3