application.conf

## actor-ts chat sample — HOCON configuration.
##
## Fields here are read by the framework on `ActorSystem.create(...)`.
## CLI flags from `backend/config.ts` (host, ports, seeds) win over
## anything set here when the chat sample wires the cluster up; this
## file is the place to tune knobs that don't change per-node (gossip
## cadence, failure detection, downing, journal plugin, log level).

actor-ts {
  # Logging.  Accepted values: debug, info, warn, error, off.
  logger {
    level = "debug"
  }

  # Persistence — SQLite journal and snapshot store, so chat history and
  # room recovery both survive a restart.  These two ids are what selects
  # them: `backend/main.ts` passes registerSqlitePlugins() to the system as
  # a plug-in (`withPersistence({ plugins })`), which registers the
  # plug-ins under exactly these names before `ActorSystem.create` returns.
  # The two file paths are set in code (under `--data-dir`, default
  # `data/`) — putting them here would tie every reader to one working
  # directory.  See `backend/main.ts`.
  persistence {
    journal {
      plugin = "actor-ts.persistence.journal.sqlite"
    }
    snapshot-store {
      plugin = "actor-ts.persistence.snapshot-store.sqlite"
    }
  }

  # Cluster timing — tightened for a 3-node local demo: a node that dies is
  # flagged unreachable after 1.5 s of silence instead of the shipped 2 s.
  cluster {
    failure-detector {
      heartbeat-interval = 300ms
      unreachable-after  = 1500ms
      down-after         = 4s
    }
    gossip-interval = 500ms

    # Who removes a node that dies without leaving.  With no strategy the
    # failure detector removes a silent node itself at down-after (4 s here)
    # and the survivors take over the rooms it hosted -- but under a real
    # partition both sides remove each other and run on as two chat clusters.
    # keep-majority lets the two survivors of three remove it once the view
    # has held still for stable-after -- about 1.5 s + 3 s after the kill
    # here -- and the minority side of a real partition removes itself
    # instead of forking the cluster.  A Ctrl+C is a graceful leave and needs
    # none of this.
    split-brain-resolver {
      active-strategy = keep-majority
      stable-after    = 3s
    }
  }
}