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Persistence for Ahnlich DB

Why need persistence?​

Ahnlich DB manages structured data like keys, values, and predicates. Running it in-memory only means:

  • Stored data disappears after restarts.

  • Predicate indexes must be rebuilt manually.

  • Any production state is volatile.

Enabling persistence ensures:

  • Data and indexes survive restarts or container upgrades.

  • Your stores can be backed up and restored easily.

  • Mission-critical applications don’t lose their data.

Configuring persistence from in-memory mode to disk​

Enable persistence by starting the DB service with persistence flags:

ahnlich_db:
  image: ghcr.io/deven96/ahnlich-db:latest
  command: >
    "ahnlich-db run --host 0.0.0.0 \
    --enable-persistence --persist-location /root/.ahnlich/data/db.dat \
    --persistence-interval 300"
  ports:
    - "1369:1369"
  volumes:
    - "./data/:/root/.ahnlich/data" # Persistence Location

  • --enable-persistence → turns on persistence.

  • --persist-location → file path to store snapshots (e.g., db.dat).

  • --persistence-interval → snapshot interval in seconds (default: 300).

  • volumes → ensures snapshots persist outside container lifecycle.

Loading from persistence​

When restarted, the DB automatically loads the latest snapshot from db.dat.

  • All stores, keys, and predicates return to their previous state.

  • No manual re-indexing is required.

  • You can back up or restore DB state simply by copying the persistence file.