multiserver

Support for running Dart applications, specifically Angel apps, across multiple servers.

The idea is that you have one master server running the load balancer, and the child applications call a session synchronizer.

Dedicated WebSocket support is also present.

See the examples;

Response Caching

This plug-in works on any Angel server, not just a LoadBalancer. It caches responses, to lower future response times.

Load Balancing

This package exposes a LoadBalancer class, which extends Angel, and can be used like a normal server.

The default algorithm is a simple round-robin, but it can be extended for your own purposes.

Three load-balancing algorithms are included:

  • ROUND_ROBIN (default)
  • LEAST_LATENCY
  • STICKY_SESSION

The LoadBalancer also supports HTTPS and WebSockets. Bam.

You can also provide a maxConcurrentConnections to pool server resources and prevent premature crashes.

Session Synchronization

This package also includes three SessionSynchronizer classes:

  • MongoDB
  • Memcached
  • Redis

These are simply plugins that serialize and deserialize session data to external data stores. Try to call them as early as possible in your application, so that session data is loaded before any business logic.

import 'package:angel_framework/angel_framework.dart';
import 'package:angel_multiserver/angel_multiserver.dart';
import 'package:mongo_dart/mongo_dart.dart';

main() async {
    var app = new Angel();
    var db = new Db('<connection-string>');
    await db.open();
    await app.configure(
        new MongoSessionSynchronizer(db.collection('sessions')));
}

WebSocket Synchronization

The multiserver is also bundled with a MongoWebSocketSynchronizer.

Libraries

angel_multiserver