rpc_notify_redis #

Redis Pub/Sub backed INotifyRepository for rpc_notify. Fans topic events out across server replicas via PUBLISH/SUBSCRIBE, so a subscriber connected to one instance receives events published by any other.

Like the Postgres backend, this is a stateless relay: nothing is persisted, and a subscriber only receives events published while it is subscribed. There is no backlog, replay, cursor, or acknowledgement. For Redis this maps to Pub/Sub, not Streams.

Quick start #

import 'package:rpc_notify/rpc_notify.dart';
import 'package:rpc_notify_redis/rpc_notify_redis.dart';

Future<void> main() async {
  final repo = await RedisNotifyRepository.connect(
    host: 'localhost',
    port: 6379,
  );

  // Inject into the notify server on every replica.
  final server = NotifyServiceFactory.createServer(
    transport: transport, // any IRpcTransport
    repository: repo,
  );

  // Or drive the repository directly.
  repo.subscribe('client-1', 'orders').listen((e) => print(e.payload));
  repo.publish('orders', {'id': '42'});
  repo.publishTo('client-1', 'orders', {'private': true});

  await repo.dispose();
}

Configuration #

RedisNotifyRepository.connect options:

• host / port — Redis endpoint (default localhost:6379).
• username / password — optional AUTH (username for ACL users).
• useTls — connect over TLS (connectSecure).
• keyPrefix — channel namespace, prepended to every topic (default rpc_notify:). Replicas must share the same prefix to see each other's events.
• healthCheckInterval — periodic PING used to detect a dead connection (default 10s).

There is no db option: Redis Pub/Sub is server-global and ignores the selected database. Isolate namespaces with keyPrefix instead.

Behavior #

• Two Redis connections are opened: one dedicated to SUBSCRIBE (a connection in subscribe mode cannot issue other commands) and one for PUBLISH.
• publish / publishTo are fire-and-forget (void); they no-op silently while the connection is down.
• publishTo tags the event with the target clientId so only the replica holding that client delivers it.
• On connection loss the repository reconnects with backoff and re-subscribes to all active topics.

Testing #

The tests require a running Redis. Start one and run them:

docker run -d --rm --name redis -p 6379:6379 redis:7-alpine
fvm dart test

Being service-dependent, this package is excluded from melos run test:unit (matched by *_redis).