Avro RPC

README.md

Sample JavaScript client and Java server RPC setup.

client.js

/* jshint node: true */

'use strict';

var avro = require('avsc'),
    http = require('http');

// Parse protocol file.
var protocol = avro.parse('./mail.avpr');
var message = protocol.getType('example.proto.Message');

// HTTP emitter, assuming the server is listening on localhost:8888.
var ee = protocol.createEmitter(function (cb) {
  return http.request({
    port: 8888,
    headers: {'content-type': 'avro/binary'},
    method: 'POST'
  }).on('response', function (res) { cb(res); });
});

// Send a sample message, and print the response to stdout.
protocol.emit('send', {message: message.random()}, ee, function (err, res) {
  if (err) {
    console.error(err);
    return;
  }
  console.log('response: ' + res);
});

Mail.avpr

{
  "protocol": "Mail",
  "namespace": "example.proto",
  "doc": "From https://github.com/phunt/avro-rpc-quickstart/blob/master/src/main/avro/mail.avpr",
  "types": [
    {
      "name": "Message",
      "type": "record",
      "fields": [
        {
          "name": "to",
          "type": "string"
        },
        {
          "name": "from",
          "type": "string"
        },
        {
          "name": "body",
          "type": "string"
        }
      ]
    }
  ],
  "messages": {
    "send": {
      "request": [
        {
          "name": "message",
          "type": "Message"
        }
      ],
      "response": "string"
    }
  }
}

Server.java

import example.proto.Mail; // This example assumes the protocol has been compiled.
import example.proto.Message;
import java.io.IOException;
import org.apache.avro.ipc.HttpServer;
import org.apache.avro.ipc.HttpTransceiver;
import org.apache.avro.ipc.specific.SpecificResponder;
import org.apache.avro.util.Utf8;

public class Server {

  public static class MailImpl implements Mail {

    // Echo each message back.
    public Utf8 send(Message message) {
      return new Utf8(
        "Got message to " + message.getTo().toString() +
        " from " + message.getFrom().toString() +
        " with body " + message.getBody().toString()
      );
    }

  }

  public static void main(String[] args) throws IOException {
    HttpServer server = new HttpServer(new SpecificResponder(Mail.class, new MailImpl()), 8888);
    server.start();
  }

}