Vertx Websocket: Load Balancing

Question

I am working on a system where I send messages to a server using web sockets. For this, I use vertx (without Rx) web sockets client with multiple verticles and the messages are stored in an internal queue. I wish to dequeue from the messaging queue and submit to a verticle is has the least load. To identify the verticle with least load I plan to use a ratio of number messages ack received to number messages sent. I understand vertx web sockets are async in nature. But is there a provision to use any of the provided handlers to parse the response which indicates the message had reached the server.

Please note: The communication is one way ie only from client to server and server is not on vertx, it uses plain netty Thanks in advance.

Alexey Soshin Alexey Soshin · Accepted Answer · 2018-09-07T15:33:08

You can use a combination of SharedData and regular handlers:

this.vertx.createHttpServer().websocketHandler(ws -> {
  ws.handler(data -> {
    this.vertx.sharedData().getCounter(this.deploymentID(), (c) -> {
      c.result().incrementAndGet((dummy) -> {});
    });
  });
});

This will increment an atomic counter for specific verticle each time a new WebSocket request comes in.

Now you can get all deployment IDs using vertx.deploymentIDs()

What's left is to iterate over those, gather the counters, then get the minimal one.

Vertx Websocket: Load Balancing

1 Answers